Paul's R2-D2 Project

YouTube Channel results for 2011

2012-02-01T19:52:00.000-05:00

I have to admit, I started the Paul's R2-D2 YouTube Channel as a way to keep all the building tips organized. I was really surprised when I took a look at all the views the videos were getting...

Re-working the CPU Arm system

2012-01-26T22:07:00.000-05:00

Back in March of 2010, I began the process of installing the CPU Arm into R2-D2. Over the next few months, I got the power antenna to work at making the probe extend and retract. However, the trick in doing so wasn't reliable.

That system had a problem with the plastic hose which caused some kinking and made it very difficult for the servo to move the arm up and down. As a result, sometimes when the arm was retracted into the body, the servo was fighting the tension of the plastic tubing to stay upright. This would cause tapping from inside R2...a pretty unique problem to solve!

Over the months, I found the Firgelli L16 100mm stroke actuator. It only has about 5 pounds of force it can handle but for pushing a resin piece that weighs a few ounces, it should work!

I hollowed out the resin cpu arm to 1 inch diameter, which is enough for the actuator to fit inside with a bit of extra space. I had two 1 inch diameter pieces cut and enough of the center removed for the actuator to not quite fit into. To assure a snug fit, I used a file to remove a bit of material and now the actuator fits inside and stays centered.


Surrounding the shims with electrical tape keeps them properly aligned

Then it was time to work on the tip of the probe. I trimmed the end a bit since it was rounded. I found a 10-24 thread female piece and bored out the holes to accommodate 4-40 size screws. I drilled and tapped into the resin and now have it so that the adaptor simply bolts into position.

And here is what it looks like all put together...

The next challenge is to make a a way for that assembly to connect to the high power servo. After a little trial and error...and a lot of thoughtful staring with a fresh pot of coffee, I came up with this...

At first glace, it looks like this entire assembly is a bit too tall...but we'll see! More in a day or two!

Front skins re-done

2012-01-24T21:55:00.000-05:00

During the summer, I spent about a month and a half dismantling the front skins very gingerl, sanding them, painting the outer layer and put them back together.

Its taken me a while to locate the pictures that detail this process but here they are, with some captions for guidance!

Step one, cover the painted surfaces with painter's tape, so that when it is time to clamp them together, they are not scratched or damaged

3M F9460PC VHB Adhesive Transfer Tape

VHB tape is pressure sensitive, so using a wallpaper seam roller (or something similar) is very handy

Seam roller

The outer skin, with the VHB tape on it, trimmed and ready for the tedious process of removing all that paper backing!

The prevent areas from pulling apart, get as many areas as possible. It is very slow work!

The nerve-wracking part, lining everything up and clamping them together! I used the coin slots as a guide and slowly worked my way to the edges

A trip to Staples and a few zillion tiny clamps are your best friends

Then the slow process of installing all the detail pieces again (a few days later)

Silicone is my favorite for attaching these pieces. It absorbs a lot of vibration and shock...and when it is time to remove it, it isn't a nightmare to do so

The octagon port can be a challenge to line up but once there, clamp, silicone and walk away!

Doors re-installed

Sporting new skin

Remembering our best friend

2012-01-01T21:18:00.000-05:00

Every R2-D2 Builder can share their own stories of the teasing and ribbing they have taken from people while they built their droids. While it is mostly harmless teasing, we're all pretty used to it. Let's face it, if I knew someone building a movie replica, I would be curious, intrigued and might jest a bit when the project seems to be taking a long time to complete.

My best friend, Jim MacArthur, was just that kind of friend. Jim loved the idea and was pretty impressed at the parts and pieces that started to accumulate over the years. However, to know Jim is to know that you just NEVER knew what he would say! He was relentless at times! However in all fairness, his teasing was hilarious. He was like a big kid, he wanted to see this thing working!

And it took a long time. I was pretty shy about drilling holes into parts that cost hundreds of dollars and took months to arrive. My fellow New England builders would comment on my slow progress. However as I learned more from other builders at our gatherings, my confidence to press forward grew. I set a goal to have R2-D2 greeting the children at my parents' home for Halloween.

I made it with time to spare.

Jim died on December 16th after a short illness.

I think one of the best ways to remember Jim and his love of this R2 is to re-post the article he wrote after spending that first R2-D2 appearance with me that Halloween.

Halloween show of The Force

by Jim MacArthur on Saturday, October 31, 2009 at 10:57pm

Several years ago, when it seemed we all had more time than sense, my friend Paul Bussiere decided on a hobby. He decided to build his own full size R2-D2. It didn't have to just look right; it had to be as perfect as he could make it using the Star Wars movies as his only real reference.

Then he found the web site where several people were building R2-D2s and some of the similar, but different robots seen in the Star Wars movies. Some of my doubting friends (I have to admit to being one of them) rolled their eyes at the idea. Paul persevered. We would talk about doing something, like a night out at a favorite Buffalo wing spot. Paul sacrificed having to save money for one part or another.

Years went by. Fun opportunities with the friends came and went. Dedication a Jedi would envy to getting the little robot built. We jeer Paul something awful. "Looks like an expensive trash can." "That Dome looks like a great popcorn bowl." "Wow, opposite sex repellent." We were wrong. He continued to work. He documented his progress in a blog that became surprisingly popular. Tonight (2009 Halloween) was the Droid Debutante.

Adding to the surprise of the evening, the camera didn't self-destruct when taking a picture of me with R2.

On his parent's porch, lit by the traditional light to welcome Trick-or-Treat'ers was the little robot making his first public appearance. I say little, but it's about four feet tall and weighs about two-hundred pounds! Fully animated by remote control.

The neighborhood is very child friendly, so we all expected a heavy turnout of costumed characters hoping for munchies that are the dentist's worst nightmare. And they came... Paul's mother had to retire from fatigue after handing out piles of candy to hundreds of little monsters that came through.

One of the many Trick or Treaters that came to see Paul's R2-D2.

I arrived just as the home team's candy supply was running out. Little face after little face, awed at the familiar robot with its lights flashing, and talking in its familiar language of beeps, chirps and whistles. I had to run for more candy! I think R2's flashing lights meant he approved.

I know Paul wanted to use his creation to entertain mostly children. Tonight, even the adults were entranced by the 'Power of the Force' from the little robot's presence. Parents asked to take pictures of R2. Kids stopped in the middle of the traditional "trick or treat" enthralled by R2 making a little move, turning its head or speaking up in its droid language.

Probably my favorite picture of a Trick-or-Treater this Halloween (2009) Paul's R2-D2 showing his Star Power!

I have never seen so many children in one place. Each one in costume. Wave after wave of wide eyes coming to see the little movie star. They even continued to come to see him after we exhausted the candy supply, hoping for a glimpse and perhaps a quick photo. This was a night I will remember for a long time. Even though all I did was cheer and jeer the building process. Even though all the work was Paul's. This was an evening I will remember for a long time. On a night where kids usually have fun, we made bright eyes that much brighter, and smiles that much wider.

The Force was with us this night.

More projector fun and Halloween!

2011-11-13T21:18:00.000-05:00

Its been a busy few weeks so let me get back to where I left off on the projector project!

With the mounting made, the power and data transmission settled, it was time to see how everything would fit. It was slow but steady work getting the mounting lined up to the holoprojector. Then, using the outside of the HP to thread it into the mounting adapter.

One thing that had to be removed for this to fit was the red-blue PSI light. I wound up using one of the plastic PSI blocks that are offered as add-ons to the 300mm dome. To keep the projector level, I used the self-adhesive hook, a small rubber strap and an eye hook piece.

As you can see, its getting pretty crowded in there!

In order for the projector to have enough power, it requires a dedicated 12v 7amp battery. The problem is where to put it! That I am still working on.

Work on the software is still on going. I threw myself a curve by trying to code from my Windows 7 64-bit laptop instead of my Windows Vista (32 bit) one. Put in non-geek terms, different versions and operating systems sure complicates things! But, we're slowly making progress.

That said, here is what the projector looks like inside the dome (I had to hinge another panel to access the projector power button from above)...

Here is how the Princess Leia video clip looks in darkness and in regular (bright) lighting...

As you can see, the top of Princess Leia's head it obstructed by the HP. This can be trimmed and adjusted in the Windows properties, lowering the alignment of the display.

So despite some technical hurdles, cramped for space and power demands, it works! I still have a good deal of refining to do but the components all check out.

And of course, we had another amazing Halloween at my Mom and Dad's place in Bangor.

We were outside in the 39 F weather to greet trick or treaters (yes, that is snow in the background!)

Again I was busy controlling R2 while the kids came up to meet R2, pose for pictures and ask questions. We were outside from 5:30 until 7, calling it quits when we ran out of candy. This was my third year doing this and it seems we have become a "must visit" spot for the kids, from what the parents were saying.

A quick peek at the projector project

2011-10-17T23:24:00.000-04:00

Over the past few days, in my free time between work and my college course, I have been working on the projector idea.


This is the idea I came up with a few weeks ago and just kept toying with

The projector is a Mitsubishi PK10 and came out in 2006. By today's standards, it is practically a relic. But I have used the newer model of these a year ago for a few weeks and had a fun time writing in some code in my control software to trigger the Princess Leia video clip. I came upon this one on eBay for $53. No cords, no battery, just the projector itself. I couldn't resist and bought it.

The resolution and brightness aren't stunning by the standards we have now, but for what we want R2 to display, should be more than adequate, assuming I can overcome some obstacles.

Powering the projector

With no battery or ac adapter, I couldn't even test the projector when it arrived. The specs on the projector say the power supply converted AC power to 15 volt, 2amp. Knowing that, I was able to search around my favorite electronics sites for something that could do that.

The Slip Ring power system I have been working on for months wouldn't cut it. At 12 volts, 2amps, the conversion process to boost the voltage drops the amps. Meaning, I could generate 15 volts but with only 2 amps coming in, it would be way short. I would need a power source with more amps. I contacted Dimension Engineering about what I was trying to do and they suggested the AnyVolt3. At a max amp of 3amps, it could take 12 volts and push it to 15 volts (or higher). It has a tiny potentiometer you twist to crank up or down your desired target voltage. Simply attach the multimeter to the leads and tune accordingly. They also provide a graph to indicate what amount of amps each incoming /outgoing voltage will produce. For 15 volts, it will do 1.85 amps. So close....but, it turns out, its enough to power the device!

That said, the projector will have to have its own dedicated power source, so I am using a 12 volt 7amp battery.

Getting video from computer to projector

The slip ring already occupies the dome plate, providing the dome with power from the batteries in the body. The computer is also in the body. So, how do we manage to get R2's computer to see the projector as a second monitor?

After reading tons and tons of reviews on Amazon.Com and NewEgg.Com, I found a product Warpia makes for streaming video from your computer to your big screen TV. The range is about 30 feet max and the reviews I read indicated the device works extremely well. Their Wireless USB Audio/Video Adapter sells for about $115 at many online stores. I checked eBay but they were much more expensive there for some odd reason. Before purchasing, I emailed their technical support team to find out what the power requirements were for the base station that hooks up opposite the PC source. It turns out the device uses just 5 volts 1 amp. Having spent a lot of time playing with 12 volt to 5 volt converters for the dome lighting, I knew that would be pretty easy to do. That done, I ordered the device from Amazon.Com which had overnight shipping for $10. Hard to pass up a deal like that!

It turns out that for both this device and the projector, the biggest challenge was getting the right power plug type to plug into the device. The projector took a type "B" plug, available at any Radio Shack. You could buy the $3.99 pack of two and solder your own leads. I tried that but the connectors are so small and hard to get at, it was worth buying the next option up. Radio Shack sells a wire with open connectors on each end, which you then push in whichever plug type you are going to use. In my project, I just cut the wire in half and now had a power plug for each device with bare wires on the other.

I couldn't match up the power connector for the Warpia device with anything they had. One fit too loose, one so tight I thought it would break it. I wound up cutting the end off the included power cord and verified that the lead with white marks was indeed positive. (Always test, never assume!)

Embarrassing true story: Always label your power leads. The projector and Warpia device take extremely similar plug types. However, one is 15 volts, the other is 5 volts. I mixed those up and fried the first Warpia device I bought. Oh sure, it lit up VERY brightly for an impressive second or two. But, then came the wiff of electronics doom and a piffle of blue smoke.

How am I going to mount this in?

The very first concern I had all along was how to mate this to the back of the holoprojector (HP). There is very little surface area to mount this to that wouldn't compromise mobility. It has to be able to withstand all the bouncing around R2 does while rolling around, being loaded/unloaded and so on. It has to stay perfectly aligned with the opening of the HP in order for the image to pass thru. It also needs to be accessible should I need to manually adjust the focus, power the device on, etc.

For access I am going to hinge the dome panel on top of where it sits. More on that later.

The HP's are threaded on the backside so that builders can install a light source and close the threaded cap. The thing is, no one knows what the size and threading is. Its rather fine so anything you find at a plumbing store will not fit, it will be too coarse. Same with various home and industrial electrical fittings.

I managed to make some new friends in my many journeys over the past few months. Roger, who works at a local sheet metal facility mentioned a sign shop proprietor who does a lot of projects and CNC/engraving work for fun. I met Fred and explained what I was trying to do. He was able to determine that the threading was 20 and most likely metric. He asked if I could leave the HP with him so his friend, another CNC operator, could investigate this unique riddle further.

While they did that, I worked with Roger on making a simple L-shaped shelf that would house the projector. What would have taken me an hour and God knows how many Dremel cutting discs, his press and brake had done in 4 minutes.

A day later I heard back from Fred and we compared notes. Fred was just as smitten with this puzzle as I was. Together we cut the access holes for the projector lens and cooling fan. His friend was able to make the perfect male threading piece and weld it onto a small piece of aluminum. Fred trimmed it down to fit over the lens opening and suggested that instead of drill/tapping holes to secure it in place that it be welded.

The next day, Fred had finished the welding work and let me know the part was ready. Once there, we put all the pieces together to see how everything would fit. Fred added some support bolts to keep the projector in place.

TO BE CONTINUED!

Repairing a noisy Rockler Bearing

2011-10-06T22:57:00.000-04:00

Here's a detailed video I made showing how to take apart and replace the stock, metal ball bearings with acetal resin ones. They are available from McMaster-Carr http://www.mcmaster.com/#9614k57/=edpnv3

You'll wind up using close to 170 so you will want two bags.

Touching up rear skins and more

2011-09-22T21:40:00.000-04:00

With the paint work largely done on the front skin, it was time to patch up the multiple drill holes in the rear skins. As I did with the front skins, I placed painter's tape on the outside and applied JB Weld from the inside to fill the hole.

24 hours later, the JB Weld has dried and it is time to take the Dremel sanding wheel flap (120 grit) to it.

Due to the weather turning quite cool on me, I had to do the touch up paint in the basement with ample ventilation.

With paint drying, it was time to move ahead on what will be next...and quite a challenge...using micro servos for the doors and panels that open. One idea I want to explore before bonding the skins together is placing servo mounts in the inner skin. Meaning, if feasible, these would be drilled thru the inner skin and provide an adhesive-free. The micro servo mounts turn out to be made specifically for the HiTech HS-85 micro servo. Some of my micro servos are too narrow to fit in the mounting. However, my local R/C shop told me about some micro servos he had just received. They will fit into the servo mounts, with slight modification. The only thing I will be replacing is the servo horn. Instead of the plastic ones included, I purchased aluminum ones from Servo City.

Now as if I don't have enough things going on at once, I'm toying with another idea for the holoprojector (HP). However, in order to do so, I needed a resin version of the aluminum HP. Wayne Orr, using my aluminum HPs created a resin version gel coated with a metallic finish. Here's a picture of it...all I need to do is clean it up with a razor blade, largely around the two flange pieces.

I'm working on a way to fabricate a mounting from the resin HP to use...well, let me show a teaser picture...

Outer skin painting continues

2011-09-18T22:28:00.000-04:00

Today the sun was out so I took advantage of the weather to get another coat of paint on the outer skin and panels.

Before applying paint, I went over the skin with 1000 grit sandpaper, wiped clean then paint!

One surprise I had was that the can of Rustoleum Satin White I bought the other day has a new nozzle. It puts out a LOT more paint at once, I managed to create a drippy run line on one side of the skins which I corrected later. With that in mind, I put another light coat of paint on the panels every 30 minutes (3 times).

On the left is the new style nozzle that the Satin White paint comes in now.

"Mokey", my non-outdoor cat who adores following me around, looks on after applying another coat of paint.

Fall is here and the weather gets cool quick, so I brought the skins and panels inside and let them get some time under an electric heater with timer.

I went over each piece with 1000 grit sandpaper and all of the panels have a really nice, smooth finish. One more coat should complete these.

The skin needed some 400 grit to smooth out the blobs that the heavier-spraying nozzle caused. Then, once smooth, some 1000 grit has it all smoothed out, ready for paint.

Another coat of paint and sanding the details

2011-09-14T23:08:00.000-04:00

Today was another muggy day but I was able to put a few coats of paint on the outer skin.

Every 20 minutes I put a light coat on to avoid going too heavy or spray paint dribbling.

Next up on the sand and paint list is all the panels and doors...we can't have the white not match now, can we?

The parts that are labeled had the labels moved to the backside, so I can keep track of what goes where. The plan is to sand the pieces with 800 grit sandpaper. This will leave most of the white paint on there but remove a fair amount as well. We aren't trying to sand down to the primer but smooth out the surface. Most of the doors have various nicks and chips on them. The area between the door trim and door surface will get some special attention so that when re-painted, they maintain the sharp edges.

It was slow work but I like how smooth the pieces are now. The areas where the paint was chipped should paint up nicely.


The charging door panel has taken quite a beating Sanded smooth, it will clean up nice

While sanding one of the doors I noticed that the door had separated some from the door trim. A few dabs of JB Weld in the separated area, then clamped, should do the trick. Tomorrow I'll sand down the excess and....weather pending....more painting!

Making some minor changes to the JAG Foot Drive

2011-09-13T22:17:00.000-04:00

It was too humid for painting so I decided to tackle another task on the To-Do list.

The original JAG Foot Drives this droid has is equipped with socket head screws. The problem with this is that once installed, two adjustment screws are blocked by the foot shell. In the past, I have used some vice grips to loosen the bolt and adjust the drive belt. However, its a real struggle once the bolt head has been clawed up a few times!

I laid the leg down on a soft surface, a quilt, to make sure i wasn't going to bang up the paint any.

I bought some hex head 1/4-20 thread screws that are 1 inch long to replace the four socket head screws I would need to adjust in the future. With these screws, I can simply use a crescent wrench now.

The first step is to take the motor off the motor mount of the drive.

Once the motor is removed and safely out of the way, its just a matter to removing the screws that hold the drive to the foot shell on top. I had to remove the ankle lock so that the ankle could pivot, allowing me access to all the screws. Once out, everything came out easily...

Now it was time to replace the socket head bolts with hex head ones...

With the ankle channel accessible, it was time for some cleaning!

With everything put back together, it was time to now adjust the drive belt with the new bolts in place. As you can see on the right, now I can access the bolts to loosen and tighten as needed.

Now all that is left to do is re-install the plastic ankle lock and we are done with this foot!

White paint for the front skin

2011-09-12T21:45:00.000-04:00

Painting is my least favorite thing to do. Its not that I do not LIKE to do it, its the spray paint and their fussy nozzles.

Today the weather was in the low 80s with a light breeze. The skin already has two coats of primer, sanded down and ready to go.

R2 white is Rustoleum Satin White and I used the applicator trigger piece that attaches to the can. I checked and re-checked to make sure the trigger was hitting the nozzle properly. I didn't want splatter, spitting or paint oozing down the can.

But...despite my best efforts, it dribbled anyways....


Despite using a spray paint adapter to prevent splatter, it happened anyways (note splotch in foreground)

I let the paint dry for three hours and then used some 400 grit sandpaper on the skin. This removed and smoothed out the splatter spot as well as the rest of the surface.

Weather pending, I'll work on getting another coat or two done!

Front outer skin sanded and priming begins

2011-09-07T21:48:00.000-04:00

Over the past few days, I have managed to do some sanding, priming, sanding and more priming when the weather permits.

First I sanded the old paint off...

Before...(you can see the many areas of chipped paint)


Sanded down to bare metal with 60 grit

Knowing I had a lot of good dings to smooth out, I went with a Filling Primer first. I then let the primer dry for an hour before sanding with 400 grit sandpaper. (400 is less aggressive than the lower grits...most people would suggest 600 between layers of primer. Knowing I had a lot to fill in and smooth out, I went for 600 since since I planned to prime and sand two more times)

The pictures may not show it very well, since grey on metal is hard to photograph, but A got amount of primer came off the skin when sanded smooth.

After a thorough wipe down, it was time for the next coat of primer, this time the Rustoleum brand primer.

The Rustoleum primer went on really well. After drying for two hours, I went to 800 grit sandpaper to get a very smooth surface on the skin.

On the back of the skin, I sanded the bare surface down with 60 grit paper. This helped clean up the edges of all the cut outs.

This roughened surface will be ideal for the Very High Bond tape when it is time to use it. Here is how the front skin looks with the second coat of primer sanded...

Before calling it a night, I brought the inner front skin indoors and clamped it onto the frame. With all the sanding work, the skins are more straight then curved, so this should help get some of that back.

This is one of those little quirks...the skin won't rest flush everywhere.

Clamping where I can to get that "bend" back in the skin.

I am going to mark on the inner skin where the frame makes contact with the skin. The idea here is that where possible, if the frame allows for it, install servo brackets into the inner skin. Like any good idea, it SOUNDS great but we'll see. All of the panels are very close to each other so finding a spot to place any servo (and require linkages) can be quite a challenge!

I'm thinking one more coat of primer, while possibly overkill, will be a good idea. After seeing all the wear and tear the skins took over two years, it can't hurt. Once the weather clears out and gives me a sunny day or two, I can do that, then a coat or two of white.

Fixed a missing panel, wound up using paint remover

2011-09-02T22:51:00.000-04:00

After spending the last few days working on cleaning up the skins, I came to the conclusion that not using a paint remover was being...ready for it...stubborn!

I bought some Zip Strip a few months ago, which is more of a gel. I used this to break up the GOOP adhesive on a door hinge last spring. Since its a gel, my hope was that it would not damage the paint on the other side should some find its way there.

I used a small paint brush, like you would use for art work, to slowly apply a layer of the paint remover on the worst spots. I waited half an hour....then started to slowly scrape and wipe away the residue...

I got as much as I could scrape up. Once this dries, I'll go over it with the mouse sander with 50 grit paper. That should complete the clean up.

However, as expected, the outside of the skin and paint took a hit.

Well...it looks like a sand, prime and re-paint will have to happen. Thankfully, the white is an off the shelf Rustoleum Satin White which I have plenty of. As for matching...well, I may have to "weather" it to match the year of wear the other white pieces have!

The inner skin has a piece that popped off when I separated the skins. It was JB Welded into position but eventually gave out. Now sanded smooth, it was time to JB Weld it back into its old spot...

Tomorrow we'll get the outer skins sanded up and primed...maybe even painted!

Inner skin done, on to the outer

2011-09-01T22:04:00.000-04:00

Tonight I pressed on with sanding the front skins.

I finally have the inner skin cleaned up. I also have the detail pieces from the outer skin all cleaned up (all the dried up glue residue is gone). The outer skin detail pieces will remain at 50 grit, since we want a roughed surface for the Very High Bond (VHB) 2mm tape to grip onto. The inner skin, which will have portions visible, will be sanded up from the current 120 grit to 220 grit, for a nice shine.

The outer skin is a bit more of a challenge. Since I am dealing with the curvature, sanding is a bit more of a challenge than the inner skin. Also, a lot of the adhesive is on this side and when sanded, tends to gum up rather than fling loose. I am using a lot more sandpaper than I thought I would be using but I am making steady progress. I am still going at it with the 50 grit mouse sander and 80 grit sanding flap on the Dremel

The 3M VHB adhesive should be arriving next week. Then I can begin the process of applying the tape to the outer skin!

Starting work on the front outer skin

2011-08-29T22:43:00.000-04:00

Hurricane Irene plowed through Maine yesterday so I out off doing any work over the weekend, not sure what to expect. As it turns out, Irene went west of me, leaving us with a bit over 2 inches of rain and strong winds gusting up to 50 mph. No damage, thankfully!

Today I went to work on the outer skin. The inside has a lot of residue from the 3M 77 adhesive. While using acetone would certainly speed this up, it would also risk seeping onto the painted side, ruining that.

I went to work with the mouse sander using 50 grit sandpaper. It was slow work, I think the Dremel sanding flap wheel would work better....but I need to pick up a new one.

Here's how it the surface looks after a few minutes under the sander...

Skin work continues - fixing booboos of the past

2011-08-24T21:45:00.000-04:00

Tonight I had to study for a final exam so I didn't spend much more than an hour on the skins tonight.

One of the things I wanted to do was finish up the inner skin panel. I want to get everything sanded and cleaned up, which means eliminating and removing two old servo mounts I had made in the skin. I plan to re-do these using smaller servos, but more on that later.

In this picture, you can see the JB Weld residue from the servo mount...

Here's the after, with only the hinge mounts for the doors remaining...

The next thing I wanted to do was use JB Weld to fill in all the mounting holes to the frame. I did them wrong the first time, years ago and had to drill new ones. Most of the time I have been covering them up with white electrical tape but here's a chance for a do-over!

I used some blue painters tape on the outside of all the holes and then filled them with JB Weld to dry overnight...

When this has dried I will be able to sand it smooth...although I may have to apply some more JB Weld to fully fill the holes.

What's the plan for the inner skin? I would like to mount aluminum servo mounts for the micro-servos to the skin. The trick will be, as is always the case, finding locations that are not blocked by frame structures. Hindsight is 20/20 and after struggling to mount servos in the skins when assembled, I would like to be able to drill, countersink flush for contact with the outer skin. I've also learned a lot about servos and linkages. The micro-servos are plenty powerful to open and close the panels and doors. But, we'll see how things look when I have the skin lined up on the frame.

Cleaning up the inner front skin

2011-08-23T22:48:00.000-04:00

This afternoon I picked up where I left with the inner front skin.

Here you can see there is a lot of glue residue from the 3M 77 (spray type) and a few spots of paint left behind around the panel openings.

Some friends asked why not use acetone and get it all done quicker? Well, there are several portions of the skin that need to stay intact so any acetone could dribble into areas, like where hinges are bonded.

I thought I had some low grit mouse-sander paper but as luck would have it, I had tons of the round type for an oscillating sander. That power tool died a year ago! I used some 80 grit oscillating paper on the mouse sander...why not use what I have on hand?

Here's how the skin looked after a few minutes with the sander...

I decided to pick up some 50 grit mouse sander and made really quick progress both on the outside and the inside. Some areas, due to the curvature of the skin, required the use of the Dremel and the sanding flap wheel

I still have more work to do on the inside but the outside is done. The next step will be to to sand the outside with 120 and then 220 grit to bring it to a smooth shine.

Tear down time...

2011-08-22T22:42:00.000-04:00

This evening I got right to work on my plans to start tearing down R2-D2 for some maintenance work.

I have this down to a fine art so within a few minutes I had the legs off.

Legs are off! Foot drives will be getting worked on in a few days!

With the legs off and the body on the dolly, I can now transport it to another room for further dismantling.

Next up is disconnecting the servo linkages from the doors that are actuated.

Since most of my servos are mounted to the frame, to remove the skins, I just have to disconnect the hinge from the linkage.

With that done, I can remove the front body skins, exposing R2's guts.

With the skins off, I got right to work labeling the tall doors so I would know which is which for the re-assemble.

I've never been happy with how the front skins came out. Over the years I have had several ideas on how to fix it but kept putting it on the back burner, tackling more pressing needs. Now that I have a break in the action I can take them completely apart and make them look like the set R2 #2 has.

I want the inner skin to be completely unpainted so that when the outer skin is on, the exposed inner skin adds to the depth of the skins. This time I can use a better adhesive and also patch a few holes from my first attempts mounting them to the frame. Last, the vent surround piece has been bent and mangled repeatedly. I friend with a CNC machine cut me a new one out of aluminum so I just need to curve it slightly and paint.

With the skins out, it was time to start removing the doors from their hinges. It was also time to slowly peel away the silicone used to mount the octagon port, coin return and power coupler.

Before

After

I used some blue painters tape to label the outer skin detail pieces that will eventually pop loose. With the skins ready to be separated, it was time to put the method I have come up with to the test.

The method I came up with wasn't to use a butter knife, nor a thin screw screwdriver. I opted to start with very thin aluminum, so I dug into my pile of aluminum flashing (used around chimneys) and used that. I also used a scrap piece of aluminum from the inner skins, the utility arm cut out.

I used the thin aluminum flashing and quickly worked my way through the areas where the adhesion wasn't good at all. Here's a few pictures showing how it worked...

Find a spot where the skins have come apart and work the aluminum flashing into it.

Slowly, and carefully, work the piece up, down and around. Be very careful, that flashing material is thin and very sharp.

After an hour of slow, diligent work, the skins are separated. Better yet, no warping, dings or distortions from the removal process.

Tomorrow I'll work on sanding the skins , namely the surfaces where they will need to have VHB adhesive tape attached. The pieces already white can stay as they are, so they match the rest of the droid.

Post event round up and what's next

2011-08-21T21:53:00.000-04:00

R2 and I have had a very busy month, especially the past week with two events back to back. We've had a few little glitches here and there and we will have some down time to address them.

At yesterday's Champion the Cure fundraiser, I had two problems crop up.

The first was the failure of a new omni-ball caster. These are hard to find now so replacing it with another new one may not be possible. This is mounted in the rear of the foot drive system and the caster failed at the threaded mount. Something inside the casing failed so the threaded end just drops up and down.

Failed caster thread screw, sinks into the casing


You can pull the threading up, note the angle

I think what may have done this caster in was the concrete surfaces we have been on this week. Your typical cement but those groves in between, causing R2 to clunk from one surface to another. The caster simply fell off when I went to lift the foot to inspect the source of some noise.

The second snafu was the receiver and transmitter. The Spektrum radio and receiver are 2.4ghz and bind to each other in a binding process that allows them to find a secure channel and communicate properly. For some reason, the radio and transmitter lost that link. I thought I was out of power on the electronics battery but testing of the battery at home showed it was still very charged. I haven't had to bind the transmitter and receiver for over a year, so for it to fail now had me a bit concerned. However, it could have been something as simple as me having hit a button while powering the radio on. From now on, I will make sure I have a bind plug with me so I can re-synch them.

Over the next few weeks, there are several things I plan to do...

Take R2's legs off and remove the foot drive from the foot shell. I want to replace the bolts that hold the drive system together with hex head ones. As it is now, if I want to adjust a belt setting, I can't...the current bolts are hex head and covered by the foot shell. This will allow me to inspect the belts and also inspect the legs and ankles for any signs of wear and damage.
Remove the center foot and examine how the rollerblade wheels and caster mount bearings are holding up.
Clean up and improve the electronics tray and wiring. Its a real mess of wires in there. Since I need to make improvements here anyways to incorporate the slip ring, now is a good time to do this.
Swap the fuse block in the dome out and use it in the body to offer more power connections for R2's gadgets. Replace the dome one with a smaller one and install another on the dome plate. This will give the dome its own fuse block, the dome plate will have its own, to power devices like the periscope, life form scanner and whatever else comes along.
Once the electronics power system is sorted out, we can resume work on the installation of the gripper claw and cpu arm, which still need fine tuning.

Its a pretty aggressive list of tweaks that shouldn't take too much time to do. The next step from there will be to get the dome panels hinged and servo mechanisms installed. I have almost everything I need to do this....just the time!

Champion the Cure 2011

2011-08-21T01:20:00.000-04:00

Today was the Champion the Cure 2011 event at Cancer Care of Maine.

For this posting, I am just going to post the pictures with some captions!


Jake Libby is my God Son, he was 7 years old when he died of brain cancer in 1995.

Out mingling

Knowing I would be pushing the limits of the netbook computer, I kept the ac adaptor plugged into it. When I got around hour # 3, I plugged into external power to keep the fun rolling!

Installing the slip ring into the frame

2011-08-16T22:39:00.001-04:00

Tonight was the slow work of fitting the slip ring into the frame.

The frame already has a circular cutout that fits the slip ring perfecting.

Last winter, when I was working on a dome positioning system, I added the holes needed to bolt the slip ring into position at a later time. I also tapped (threaded) them to accept 4-40 threw screws.

Side Note: In the above picture, I also want to add a small electronics tray that is mounted under the cross member. The tray I am pondering would fit between the fold-out electronics tray (bottom) and go up til the cross member piece. This way the gadgets to fold out and in, like the Gripper Claw and CPU Arm can fit inside. I would like the ServoCenter card for R2's body, the sound card and eventually, the Slip Ring connector card all on one tray. This also frees up that entire area between the shoulders for the computer.

The fun part was GENTLY folding the DB25 connector (clam shell removed) and fitting it through the hole in the frame.

Now that I have carefully folded and un-folded the DB25 leads, its time to see how well my novice soldering has held up.

I went through and tested for continuity. Thankfully, everything works! With that done, I can now re-install the clam shell onto the slip ring connector that will stay in the body. Once I had done that, I AGAIN tested to make sure that none of the soldered leads came loose and failed.

Next time I'll work on the small tray I want to install under the slip ring for the electronics to mount on. This will free up some space for the computer to sit between the shoulders. Also, with the ServoCenter card being removed from the back of the electronics tray, routing the servo wiring will be a lot easier. I'm using a LOT of extension cables so making the card more centrally located will be an improvement.

Then, the top portion of the slip ring connection will need to be fit thru the dome plate. More testing to make sure the wiring survived and THEN, on to getting the connection cards mounted.

Fun times!!

Dome electronics prep

2011-08-15T21:52:00.000-04:00

Tonight I wanted to get the electronics mounted on to mounting plates with standoffs. With the slip ring and connectors complete, I can get these done while awaiting some fuse blocks to arrive.

I found that the input pads on the ServoCenter are the for use with prong leads that solder on. I soldered on some 2-prong leads and just needed to find some 2-wire female leads. I had servo wire, but that is 3-wire. One of the other builders made a great suggestion: computer jumper leads! I have a few old PCs in the basement so I just snipped off the leads that go from the power supply to the motherboard. These are where the PC speaker, power switch, reset and other case features plug into the motherboard.

I didn't have any aluminum scrap wide enough for the ServoCenter card so I opted to cut up a piece of FR4 electronics board.

I used some 1/2 inch female-female 4-40 thread standoffs for the card and opted for double-sided tape for the Pololu 12v to 5v 3.5amp power converter. Its so small, there isn't any area to screw or mount it to anything.

The left side, orange and black lead goes to the power converter, this will be the source of 5 volt power for all the servos controlled by the ServoCenter. The blue and black lead goes to the 12 volt input for the card itself. This will plug into the fuseblock the Slip Ring will power.

As I said, the power converter is tiny! I also put a cable organizer under it as all those servo wires and other leads are going to get messy quick.

For the slip ring connector card, I opted to place it on its own piece of aluminum material.

Here's the completed pieces tonight.

What remains?

Well, I need a small fuse block (ordered) to replace the larger one in the dome now. I need that one in the body as I am out of power leads there.

The setup, as I have now, routes power directly into the dome servos. I will eventually need to splice that to the dome plate, to power the dome accessories, such as the periscope and life form scanner. Since the slip ring board has two power leads, I just need to create a quick-release connector for easy removal of the dome. The slip ring connector would unplug, by design, from the ServoCenter. A second quick-release would disconnect between the slip ring card's second power lead and dome plate fuseblock.

Clear as mud, right??

Hospital visit & Fundraiser!

2011-08-12T19:49:00.000-04:00

Thursday was a busy day for R2-D2 and I.

My friend, Charity, asked if we could pay a visit to her son and then participate in the Fundraiser Spaghetti Supper after. Her 7 year old son was involved in a lawnmower accident that severed his foot.

I've known Charity for a long time and she works at the same organization I do. I told her we would be happy to do so!

I brought R2-D2 to work the night before, so we would ready to head straight over and visit her son after work. The staff I work with has a few new employees, so they were thrilled to meet R2 after hearing all about it for weeks.

We went up and visited with the kids on Peds and then paid a visit to Charity's son. She took some really great pictures and sent one to me to share on the blog. (This is one of the rare, few photos I get to see of R2-D2 in action with a patient due to privacy laws)

After visiting for an hour, we got packed up, had Security help me lift R2 into the Odyssey and then drove to the VFW Hall in Old Town for the Spaghetti Fundraiser being held to benefit Charity and her family.

The place was PACKED. Lot's and lot's of people! An outstanding turn out! With the help of some helpful strangers, we unloaded R2 and headed inside. A very enthusiastic group was anxiously awaiting our arrival.

As always, the kids had a LOT of questions and requests ("Build me one!!") I spent the next two hours maneuvering R2 around so kids and adults could pose for pictures and video clips. I always wonder how many of those become profile pictures on Facebook!

Charity's family posed for pictures with R2-D2...

Over $7,000 was raised!

R2 ran very well, with the exception of a problematic center caster. It seems the change I made in the foot drive caused a few minor headaches. More on that later!

Star Wars Day at the Newport Cultural Center

2011-07-24T14:20:00.000-04:00

Saturday was Star Wars Day at the Newport Cultural Center. R2-D2 and I attended this event last year and appeared with the Mandalorian Mercs, a Bounty Hunter group.

As it had been all week, it was extremely hot and humid outside. Just loading and unloading R2 into the van got the sweat going. Thankfully the Cultural Center is air conditioned.

The Mercs appeared first, with about 50-60 kids waiting to greet them. R2 and I came in about 15 minutes later.

After posing for pictures, everyone headed to the conference room for Star Wars Trivia. We ended the afternoon snacking on Wookie Cookies and thanking our hosts for having us over.


Mercs are set to head out and greet the crowd


Picture time


Yours truly, taking pictures

New England R2 Builders Summer Get-Together

2011-07-19T22:36:00.000-04:00

Last weekend was our annual get-together. I say "Annual" because we always manage to have one...sometimes a second one before the end of summer or fall!

Kevin Helmig hosted the event from his spacious new home in Amherst, NH. That made for a 3.5 hour drive for me and others came from other impressive distances as well.

The New England group really spans beyond that. Many are in New York, Canada, New Jersey (What exit? Sorry, old joke!) and points beyond. We try to pick a date and location that works for everyone.

Here's some pictures...


This is the prototype Lifter/Riser device for use in the dome for the periscope, life form scanner and potentially the light saber chucker!

Those incredible aluminum JAG rocket boosters

This is my second R2-D2 sporting some new modifications


The wood blocks keep the ankles locked in place.

The weather was hot, very very hot! We had about 15-20 builders of various phases of build. What's really great about our gatherings is we aren't walking around with pocket protectors, quoting the movie. We all have a sincere, genuine passion to build the R2-D2 robot we all like from the movies. Everyone has a favorite film, everyone has a different way of doing their build. You learn so much when you can interact with other builders and see how they went about their droid, different materials and so on.

I'm already looking forward to our next gathering! We plan to work on our group plans to get to the Star Wars Celebration Six in Orlando, FL next summer!

Barbara Bush Children's Hospital visit

2011-07-18T21:18:00.000-04:00

Last Friday R2-D2 and I paid another visit the BBCH in Portland, Maine. They are a 2 hour drive south from me and they asked when I would be in the area again. Since this is the weekend of the New England R2 Builders get together in New Hampshire, this date worked out well!

I invited my brother, Greg, to join me since he lives right in Portland. We put him to work, handling the digital camera for the staff so they can print the pictures out for the staff.

Once up on the floor, I prepped R2 and disinfected the surfaces with the wipes they provided. We were set to go and the Child Life Specialist lead the way for us.

As usual, I can not take pictures with the patients due to privacy but one parent gave us her blessing to share a great photo of her daughter with the child life specialist and R2-D2

One of the volunteers named "Ann" was fantastic to work with.

Once we finished up, my brother posed for a photo with his aluminum "nephew"...

And of course, all of us together...

We really enjoyed our visit with the children and staff. Greg had to head out and R2 and I stayed put for a little while for staff and families to pose for pictures. The security staff was gracious enough to provide us with a large cart and muscle to load and unload R2 to the floor.

Trips and events like this make the whole R2 building experience extremely rewarding. We brought many, many smiles today and look forward to visiting again sometime soon!

Wiring up the Slip Ring Connector & testing it

2011-07-13T23:12:00.000-04:00

Tonight I picked up where I left off, resuming the process of slowly soldering in the wire leads. The nice part about the first end is you can put any wire anywhere, you have to match it up on the other end!

I found that if I put a small amount of solder on the top of the connector, then slid the wire into place wearing a shop glove, I could then re-heat that solder and it would fill around the wire.

Every 4 wires, I would stop and test the connection with the multimeter, this way I didn't get too far ahead of myself. I used all the solid colored wires first, then went on to the rest from there. Once I had the connector all wired up, I jotted down what color wire was in what pin in the connector.

Next up was to slide the shrink wrap down to help reinforce the connectors to the wiring. Since I lack a heat gun or a hair dryer (I'm bald...seriously!)...I used a match. Some of the shrink tubing I used at first was too thin, the stuff I bought recently fit perfectly over the connector....

Again I wont win any awards but for a first effort...I'm happy with it.

Next up was assembling the DB-25 clam shell and squeezing the wires to fit.

Happy that everything went together, I opened the clam shell piece up and wanted to again test all the pin outs and the wire leads on the other end of the slip ring. After all the work so far, I wanted to make sure everything was still checking out OK. I mean, 24 thin wires on little connectors...and a lot of shoving and tugging...something HAD to pop loose, right?

Much to my surprise, everything checked out as working fine!

Now I just need to tin the wire leads on the other end and connect those into the other connector. Half way there!

Tinning the slip ring wires and connecting to the DB25 connector

2011-07-12T22:46:00.000-04:00

Up here in Maine we are in the midst of the hot, muggy days. Once the temperature goes past 75F and the humidity rises to over 65%, I start to melt. As such, I took refuge inside, enjoying the air conditioning and getting some more work done on the slip ring.

First I had to pick up some more thin shrink wrap tubing and a DB25 clam shell, which will eventually cover the connector. My local retailer, ICC North in Brewer had everything I needed. (I love supporting local small businesses whenever I can)

The next step was to make sure the wires were twisted and ready for tinning. With such a thin wire, you do not need to very hot iron. You heat the wire from underneath and slowly apply the solder to the heated wire. It goes on very smoothly and just requires some practice to go on well. With 48 wire leads, you will eventually master it!

Now it is very important to have a multimeter handy for the next step. As you solder in the wires into the DB25, you can to test each end ....put a paperclip in the DB25 and touch a probe on that side, then on the other end of the slip ring, touch the matching bare wire lead. You want to make sure you have continuity and verify the connection will work.

The trickiest part is getting the leads into the DB25 connector. Someone suggested putting some solder in the "bucket", heat it and stick the wire in. Don't do that. That's sucks! Without burning yourself, I found the best process was this:

1) Make sure you trim the wire lead so you do not have too much exposed wire showing.

2) Put a small amount of solder on your solder iron.

3) As you place the wire lead into the connector, use that small dab or solder to position the wire into the bucket. Its really hard (for this newbie) to get the iron in the right position around those little connectors. I added more solder when I was satisfied I had a good connection and verified it with the multimeter

I have the shrink tubing already on the wiring, so when all the soldering is done, I can reinforce the solders with that.

Per the instructions, I skipped pin 7 since this is a 25 pin connector and we have a 24 wire slip ring.

As you can see, my soldering will not win me any awards...and hopefully will improve as I go!

Prepping the Slip Ring

2011-07-10T21:55:00.000-04:00

After doing some more research on the slip ring setup others have done, I felt I had enough information and confidence to proceed!

The wires need to be stripped back about 1/4 of an inch so they can be tinned and installed into the DB25 connector.

Its very slow work, the wire is very thin. I wish my wire stripper could do 28 gauge wire. I used the cutter to gently tug the outer layer off. On a few, I pulled away some wire too.

The next step is to find some very small wiring shrink wrap and cut it into small sections. We do not want the wires touching one another or contacting other leads once soldered into position.

As I slid these onto the wires, I clamped them into an alligator clamp so they will not fall out. I ran out of shrink wrap tubing so I will pick some more up tomorrow and begin the process of tinning the exposed wire ends.

More tomorrow!

Assembling the Slip Ring connection cards

2011-07-09T23:15:00.000-04:00

Today, after gaining some more information on how piece these together, I started work on them.

The kit that was offered last year consists of two cards that are used on each end of the slip ring, an electrical connector that rotates 360 degrees. The Slip Ring has 24 wires which are eventually soldered to two 25 pin connectors. Each other those plug into a card like these, allowing for electrical power and signal communications to pass thru.

The first step is to place and solder the two-terminal screw connectors. I used tape to hold them into place, flip over and then solder.

Once those are soldered into position, the next step is to place the signal pins into the PCB. They fit very snug and while they probably do not require soldering, I opted to do so while I had the iron out and ready to go.

The pins are very small and my soldering iron tip seems to have two settings; too cold and too hot. I am trying to not damage the pcb with the soldering iron being too warm. I just slowly apply heat to the connector and let it melt the solder.

Next up is installing the 25-pin, right angle connector. No soldering is required for this.

I did the same thing to the second slip ring connector card. The next step is to do some pre-planning, to make sure the center of the frame has room for the connector to fit thru it. Then, after referring to the manual that came with this, determining what wire will go where. I need to purchase some terminal blocks so that the one 12-volt lead can be split up to go into the two inputs on the card.

Visit to Barbara Bush Children's Hospital (Maine Medical Center, Portland)

2011-06-24T19:16:00.000-04:00

Today was my trip to the Barbara Bush Children's Hospital, which is part of Maine Medical Center. Located in Portland, its about 2 hour drive south from me. Road construction and rainy weather added some time to that but when you have the right music, who cares, right?

Like most of my hospital visits, due to patient privacy (HIPPA) laws, I can't photograph the patients with R2, unless they have signed consent forms agreeing to it. Since I have both hands busy controlling R2, I do not take many pictures.

My friend, Christina, joined me for this R2 visit and acted as the official photographer for the Child Life staff. The pictures will be printed and given to the kids.

As is usually the case with patient visits, after R2-D2 was given a thorough disinfectant wipe down, we do a quick system check, make sure everything is working normally and then follow the Child Life Specialist around. "Alice" was fantastic to work with, leading us from room to room, making sure the patient was awake and wanted a galactic visitor!

I honestly don't know who had the biggest smiles. The patients, the families or the staff!

One family gave me the "Ok" to take a wonderful picture of their little boy with R2. I had R2 playing the disco song "Staying Alive" from the BeeGees and the little guy would clap away with a big smile...

I lost track of how many children we visited but we had a great time.

* * * * *

The night before the journey, I discovered what has caused two blown fuses at the Children's Miracle Network Telethon.

It turns out that the thick 10-gauge wire that goes from the drive batteries into the RoboteQ AX-3500 bends at a sharp angle. When R2 takes a large bump, this one power wire seems to get yanked, pulling upwards on the tab. This has slowly pulled it loose of the solder connection, so the pin portion of the tab is sliding in and out of the solder joint.

I did some very delicate solder work to heat the tab and re-apply some solder to the top portion of where it meets the circuit board.

Then the more delicate work was to slowly heat the pins on the other side. The camera couldn't focus very well but essentially it looked like to solder doughnuts, with the pins sliding in and out. Now, after some careful heating, it has been re-soldered and is back to new condition.

Installing a servo in the gripper claw that will fit R2's door opening

2011-06-20T01:02:00.000-04:00

Tonight I was finally caught up with my college term papers and could unwind with some R2-D2 work.

One thing I have been anxious to try was two servos that might be the potential to replace the gripper claw's medium size servo. The servo is too tall, so that when I try to move the gripper claw in and out of the door opening, it hits the door hinge.

The first servo was suggested by Warren over the King's Mountain R/C. This HS-75BB is shorter, used for R/C aircraft retractable landing great. It has the same spindle size as the existing servo, that is where the servo horn slides onto the servo.

Before I got too carried away, I took a "before" picture in case I have refer to it...

Once the screws that secure the claw to the servo are removed, you can see the plastic horn it attaches too. Mine came already installed and you can already tell by the rough plastic edges and holes, whoever installs these has a lot of customization to do.

With the screw removed that holds the horn onto the servo, you can see how the servo needs to sit very flush to the gripper.

With the servo removed, you can see we already have a little problem. While the HiTec servo is shorter, its a lot wider.

I decided to line up all the servos...the HiTech, the one that came with it and a "Mighty Feather", a very strong HiTec micro-servo.

It looks like the HS-65MG (Metal Gear) is going to be the way to go.

I compared the servo horn that came with the gripper to the horn that comes with the micro servo. Since the spline is smaller on the micro servo, I can't just use the old horn on it. I widened the holes to match that of the old horn but careful to be a bit under, so that the screws that thread in can "bite" into the horn.

I also had to widen the mounting holes on the ends of the servo.

The micro servo is smaller so the mounting holes will not work. I "guess" where the holes should go, which will just wind up widening the existing ones.

One photo doesn't do the hassle this was justice! Its close to possible to twist the nut onto the screw. I also had to use some spacers to allow for the servo to mount securely.

The servo horn had to be trimmed so as not to hit the supporting structures.

The micro servo sits a bit lower and as a result, the gripper arms will too. This means they will make contact with these pan head screws. These need to be replaced with 4-40 flat head screws and the holes countersunk for a flush fit.

Since the arms sit lower, the spacer the other one uses needs to come out. I found that this nut plus a thin washer worked well.

And here it is, all back together. Making sure the arms are aligned properly is a bit of an optical illusion if you use the geared teeth as a reference. Instead, use the mounting holes.

Now you can see, after all that work, that the smaller servo will make fitting in and out of the doorway better. With the larger one, it was bumping into the door hinge.

And here is an example of how just changing out this servo has gained me a bit more room to work with.

It looks like, in order to have a gripper claw, I will have to accept that it will have to open straight out the middle to the door opening. I wanted it to open at an angle, so that the arm would extend straight out in front of R2, rather than off center.

More tomorrow!

Second ServoCenter card arrives

2011-06-15T22:09:00.000-04:00

The second ServoCenter card arrived today. This one will be installed in R2-D2's dome and control all of the servos via computer control. The card will communicate with the first card via a slip ring wiring connection. This, like your steering wheel, allows for an electrical connection thru a rotating linkage.

I'll have to solder external power connections for the card and the servo power source, just like I did the first card. The cards communicate with each other via a serial (DB9) connector. Only 3 wires (pins) are used to establish a TTL data communication between the cards. I can route those three wires thru the slip ring. I can daisy chain many of these cards but two should be fine.

Like everything else with R2-D2, the challenge will be mounting the card inside the dome and the wiring fun.

CPU Interface Arm complete re-do ( Part 1 )

2011-06-12T00:39:00.000-04:00

Last September I spent several days working on my first attempt on a functional CPU Interface Arm for R2 (Link). While that did work well for a while, a few consistent kinks kept making the device unreliable.

The automotive power antenna motor was bulky and awkward to install inside the body. The "plumbing" that attached the CPU arm to the power antenna had some serious drawbacks. The problem was that thick plastic tubing going from vertical to horizontal made for some real challenges. It eventually became too much for the large scale servo that would pivot it in and out of the body. The poor servo would jitter and rattle as it struggled to hold the arm inside the body.

Tonight I started on my new plan to hollow out the resin cpu arm with a one inch diameter drill bore. As luck would have it, my drill press isn't tall enough for the drill bit and the resin arm to fit, so I will have to use my vice and power drill.


The nice thing about drilling in resin is you can use wood or masonry bits. Have the shop vac handy, it gets messy quick!

As you can see, I didn't do a great job being right in the center as I had hoped to be. The pre-existing holes from my previous version made that a real hassle. With this bored out to 1 inch diameter, the Firgelli actuator will not fit without some additional work. This is a good thing since we have a square peg in a round hole. The idea i went with was an double-cut metal file, which removes more material than a single-cut one. Essentially, I am creating four flat sides, checking often to see how the actuator fits inside.

After cleaning up all the resin debris with the shop vac, I sized up how the actuator fits...

Since its getting late, I decided to stop there. The next step is going to be cutting some Lexan circles and cutting out some material in the middle. This will create a mount for the thin part of the actuator so that it lines up straight. Eventually the CPU arm probe will attach to the tip and needs to retract and fit flush.

There is a little more work to be done to determine how far into the CPU arm the actuator needs to go. As you can see in the picture below, the actuator is a really good fit for arm.

Next time we'll work on those mounts and see how this idea of mine goes!

2011 Children's Miracle Network Telethon

2011-06-05T22:56:00.000-04:00

Saturday was the CMN Telethon at the Bangor Mall center court.

As I did last year, I asked for and received permission from Sears to unload and setup there. I arrived with plenty of lead time, just in case any technical issues arose. The staff was great, helping me unload R2 and allowing me to use a side office next to the big screen TVs. ( I used to work there part time back in 2004. My friend John Dunning, who still works there, was a great liaison to get this all planned!)

Like last year, I knew it would take over half an hour to travel the 100 yards from Sears to the mall's center court. Since I had no technical problems, R2 played around the big screen TVs and appliances, posing for pictures with staff and passing customers.


Anyone know how to remove the lint filter from an R2-D2?

R2 and I had a fun stroll from Sears to center court, where all the action was already underway. We checked in with the Community Relations folks to let them know we were here (I suspect the throng of children might have tipped them off). I checked and double-checked for any huge bumps near the set. Last year, a large bundle of power cables made for a difficult obstacle to drive over. When we thunked over it last year, we popped a blade fuse that goes to the motor controller. It was easy enough to swap out, I keep a huge stack of spare fuses in the dome...but a bit embarrassing!

We were told we would be on in a few minutes and it was a good time to roll on set and get in position. I observed a 2 inch think cable taped to the floor. Remembering last year, I slowly drive to it and went to drive over it. It wouldn't go. It didn't appear too big, so I backed R2 and hit it a little bit quicker. This time we made it over. And stopped. Dead. Again.

Quickly I pushed R2 into place. I did a quick check of the controls. Everything else worked. It had to be the same problem as last year. Oh well, we pressed on and waited the cameras to turn red.

Five, Four...(just like Wayne's World)

I've done a fair amount of TV interviews now but its amazing how the live ones nail you with instant dry mouth! But we made it through the interview. I was asked to bring some DVDs they had of the saga on camera with me but as you can see, with two controllers, I am out of hands. Carolyn asked how the "girl" R2 was coming along and I answered that construction is on-going. But, I assured her, when complete, they will have separate rooms.

After the interview, I quickly inspected R2 to see if my hunch on the fuse was right. I was. Sure enough, its the connector on the AX3500. The 10 guage wire is at a 90 degree angle onto the board and when the bump hits, its pulling the connector up on card. Luckily the fuse is taking the hit but I need to either move that card or get a new connector.

With a new fuse in place, I moved R2 to a less busy part of the set to let people take pictures with R2. I had a lot of people asking how long we would be around. Kids had seen R2 on TV and wanted to come see us. No problem, since we were on at 5:15 I told them we would stay for 2 hours.

We had a lot of kids and a lot of great interactions. John took a lot of great pictures...

R2's batteries all held up very well. When I brought R2 back to Sears, the netbook was down to 22 minutes of power. With some help from the staff, I had R2 loaded back up and ready to go home.

Public events are a mixed bag, I am learning. I am used to the smaller setting of visiting patients in their room. This time around, R2 went home with a fair amount of damage from kids poking and touching after being asked repeatedly not to. A center vent piece got pushed down on and broke, the front blinking red-blue light lens is damaged. I had a mother watch while her child flipped the lighting switches on R2's dome off and on repeatedly. (The dome lighting is a few hundred bucks) While not damaged it certainly is frustrating to do so much work and see it taking a beating as parents stand by and watch.

Over the next few weeks, I'll work on repairing the damage. R2 is due for a total overhaul into the new frame and I may do that during my week off later this month.

All things considered, we had a great time meeting many new friends.

Getting R2 prepped for our next appearance

2011-06-03T23:39:00.000-04:00

This evening I spent some time making sure R2 is set to go for the Children's Miracle Network Telethon tomorrow.

The batteries are all fully charged and set to go. I inspected the frame and made sure the ankles, leg and shoulder connections are all tight and torqued up.

One problem I found was the door on the rear skins. The top edge of the skins have separated again, requiring a few dabs of Super Glue and some clamping. The way the door slides in via the tabs seems to pry the edges apart every few months.

Tomorrow we'll get everything packed up and head to the Bangor Mall. The local Sears has graciously allowed me to unload R2-D2 there and get setup. They did the same thing last year and it made for a very smooth experience getting in and out of the mall.

My plywood ramp is on its last leg and I have been asking around for suggestions or help with something else. Its too narrow and short. I would really like to be able to roll R2 up and onto the Honda Odyssey without begging for help lifting R2 up or down. Several have sent me links to various aluminum and other devices but I can't afford those. I have seen the power chair/scooter lifts some have sent me info on. Very slick! Maybe someday!

More gripper arm work

2011-05-30T22:27:00.000-04:00

Tonight I spent some time on the gripper arm. I would really like to have this working for the event this weekend but I keep encountering more and more issues.

As you may recall from previous entries, getting the right sized actuator and reducing the size of the linkages. So the good news is that it fits the doorway. The BAD news is that the servo that opens and closes the claw barely does.

The pictures may not be a great illustrator of the problem, but the servo comes right into contact with the hinge. You can also see how tight it is on the left side, clearing the door.

Now recall, if this just had to pivot straight out of the body, no problem. But, R2 is round and in order to compensate for where straight ahead is, the arm has to open at an angle. I had to do the same thing for the CPU arm several months ago.

My first thought was to see if I can replace the servo with a smaller one, such as a micro one. The servo that this gripper uses is a very unusual, "medium" sized Chinese model. It has the same spline (round gear cog the servo arm slides onto) as a regular servo.

I have an idea or two about, perhaps, getting a micro server to fit in there. As you can see, how the servo hangs from the claw...

I could remove the servo completely but the "wow" factor of the claw opening and closing is really sharp.

Well, more in a bit...a few more ideas to try!

Fixing something that has bothered me for age....the location of the dome drive

2011-05-23T21:52:00.000-04:00

One thing I have been meaning to do, especially with R2's doors opening and closing, is move the dome drive to the back of the frame.

With the doors open, the motor is clearly visible. It also makes it impossible to install any gadgets inside that panel....

Moving the motor bracket is just a matter of drilling two 13/64 holes for the mount and one for the spring retainer to latch it to. Quickly tapped to a 1/4 20 thread and figured that's all it would take.

Til I discovered the bearing inside the dome drive mount was pretty much shattered...

Despite the broken pieces, I put the bearing back together minus the fractured casing. Since the bearing isn't exactly essential, I got the drive and linkage hooked up again.

I am not going to invest too much time in this frame but with our next appearance being on the Children's Miracle Network Telethon in two weeks, I would like to see if I can get the gripper claw working. We'll see!

A few recent tweaks: Bigger battery, dome battery holder and a speaker fix

2011-05-18T22:39:00.000-04:00

With the flurry of activity I have had recently, I have not had a chance to document some of the changes I have made to R2's electronics.

One of the first minor issues I had was in the dome. When I was testing to see how to hinge the pie panel, I had to re-locate the fuse block. The fuse block was part of my battery mount, I essentially use velcro straps to wrap the 12 volt 2.3 amp battery to it. In the new location, there isn't any room behind the fuse block. The rear holoprojector is in the way.

My solution was to continue to use the velcro straps but to use two of them, drilling a small wood screw thru each into the plastic dome ring. Its not a very high tech solution but it works. Using one strap, the battery wiggles around when the dome moves. With two, it stays in place just fine now. I also used a long velcro strap horizontally to strap it to the fuse block for additional support.


Remember all that hard work removing silicone from the panel to test the hinge? Its all sealed up again! It was making too much noise without a servo linkage installed to hold it in place.

The next change was the electronics main battery. I was using two 12 volt 7 amp batteries in parallel, which gives you the same voltage, double the capacity (amps). While this worked well, those two batteries were stacked between the two 12 volt 18 amp batteries for the drive system. I was always worried these batteries would shift while moving or the connectors would slide off.

My local BatteriesPlus store has been a wealth of information all along the way in my R2-D2 Build. When I stopped over to see about adding a third 12 volt 18 amp battery, the gentleman there pointed out that for a little bit more, I could go with a deep cycle, 12 volt 20 amp battery. Being deep cycle, I would have more amps and longer battery life. Best of all, its the same size as the other two batteries. Also, this battery powers more devices, all the electronics like the newly re-done sound system and all the servos & ServoCenter card. The only con is that it does not have the slide on connectors like the other batteries, so I simply clamped the wire leads into the battery. In the future, I want to make quick-release connectors so getting the battery out and un-plugged is a quick process. Right now you have enough wire to get it out of the battery holder but its a little awkward tightening and loosening the bolts.

The newest arrival hasn't been installed yet...we'll get to that in a day or two. These are Bass Blockers from Crutchfield. Essentially, for $10 a set, these wire in between the amplifier and speaker(s) and prevent bass distortion . Since R2 plays a lot of the Star Wars music and will be upgrading to 3.5 inch speakers, I thought this would be a prudent investment to improve sound quality. You can read more about these Bass Blockers at the Crutchfield website.

R2 and I have a short break until our next event. I need it since I have just re-enrolled in college after a 20 year break! Courses began the first of May and I am having a really challenging time managing my time for work, schoolwork, R2 work and events!

LifeFlight 1st Annual Reunion

2011-05-16T22:38:00.000-04:00

Sunday was the first LifeFlight Reunion Party for all the young patients they have flown. This gave the children and their families a chance to reunite with the LifeFlight staff.

The event was held at Owl's Head Transportation Museum (http://www.ohtm.org/)

R2-D2 and several clowns from the local Anah Temple were the entertainment for the kids...and adults!

Kids of ALL AGES enjoyed R2-D2


Local media were on hand covering the event

You can see video of the event HERE

Habitat for Humanity's Family Day

2011-05-14T23:05:00.000-04:00

Today was Family Day at the new Habitat for Humanty ReStore.

R2-D2 and I were invited to join the festivities which included many great give-a-ways. Local radio station KISS 94.5 was broadcasting on site and made many mentions of R2-D2 being there. We had lot of kids stop by and the looks on their faces were amazing.

Thanks to a battery upgrade the night before, the electronics ran all day!

One of my favorite pictures of the day

Even the local Trekkies broke the Prime Directive and posed with R2

This was the scene all day long

Visit to Fruit Street Elementary School

2011-05-07T13:12:00.000-04:00

On Thursday, R2-D2 and I spent the entire school day at the Fruit Street School.

We had been contacted by the school librarian, whom we share a mutual friend. Last fall they had inquired about having R2 make a visit to the school. They wanted to make it part of something the kids were learning about. They also wanted to figure out the best way for the kids to meet R2. A large assembly or have each class come visit us in the library.

With over 300 students ranging from Pre-K to 3rd grade, they decided on having each class or two come to the library for a presentation with Questions and Answers (my favorite!).

Like past school visits, I do not have any pictures to post since I do not have the appropriate approval to do so.

We started at 9:15 and for each class, R2 came out from behind a bookshelf, greeted the kids by driving around, beeping and interacting with them. The kids asked some really good questions. For most events, people are more interested in the technical aspects of how I built R2. With the kids, they are asking personal questions of R2. What's does R2-D2 eat? What does this do, what does that do? Does R2 have a girlfriend? Where's Threepio? And so on.

I had a short, 30 minute lunch break at noon. I was able to plug R2's netbook and body electronics batteries to the charger during that time.

After lunch, we continued with the remaining sessions. R2 kept working perfectly until the very last class. The dome battery started to run low on power, so the logic displays that randomly blink and change color were staying on, meaning the voltage was getting low.

To R2's credit, this was the first time we had done an all-day event like this. For everything to work for almost 7 hours straight is great!

The entire staff and children were great. The 1st graders asked me to join them for lunch, so I did (I have lunch with adults all the time! Why not hang out with some 5 and 6 year olds?). It was a lot of fun to eat lunch with them and notice I was among the few with front teeth!

With the recent changes to the sound system, it was really surprising to see how well the power system is doing. R2 and I are enjoying a well-deserved weekend off before we prepare for a weekend of back-to-back events next Saturday and Sunday!

Space Day at the Challenger Learning Center!

2011-05-05T22:50:00.000-04:00

Wednesday was Space Day at the Challenger Learning Center in Bangor (Maine). R2-D2 and I received an request to join the festivities a few weeks ago.

This was my first event since changing over to the new sound amplifier. It worked flawlessly.

The event had a LOT of kid and adults in a pretty confined area. R2 was pretty much mobbed from the time we rolled in.


Somewhere in there is an R2-D2...

As usual, in a public setting like this, the kids have their hands all over R2. The touching is fine, its the kicking, sticking fingers in lighting and yanking on things that are nerve-wracking. Most parents are pretty good an tending to their kids. Others, well, not so much. I kept having to ask kids to not touch, only to have them do it over and over again. This was one of those situations I really thought someone was going to punch out a very expensive light or break something on R2. We rolled into another room with less people to escape the fingers for a bit!

The guests invited to the open house were many and varied. I didn't get a chance to interact with many of them since I was busy guarding R2! They had one of the gloves the astronauts use in space to work and a gent was there who trains astronauts. The local news did a live broadcast at 5/530 and 6pm.

The weather didn't cooperate with heavy rain all evening long. This made loading R2 after the event a very wet operation.

Before leaving I had a chance to interact with several students from the University of Maine and their electronics and robotic work. It was quite something to see what they were working on (and to have FUNDING!). They were very impressed with R2-D2 and I demonstrated how I have it all set up with the netbook, XBOX Controller and so on. It was really fun to see their reactions to how I have overcome hurdles along the way. They want meet up with us again and work on some ideas together. I can't wait!

Replacing the 300 watt amplifier with a 2x25 watt model

2011-05-04T23:21:00.000-04:00

The 300 watt amplifier I have for R2-D2 uses up a LOT of power. It also takes up a fair amount of space inside the body. Powered by a 12 volt 18 amp battery, the battery life isn't as long as I would like it to be for events that run a few hours long.

Recently one of the other builders posted a link to a very small and modestly powered amplifier on Parts Express.

While on their site I checked for something I hadn't found locally...3.5 inch speakers by Pioneer. I've read good reviews of a particular model for a few months now and it was on my "To Do" list for a while. They had them so to save on shipping charges, I opted to purchase both.

And a few days later, they arrived...

I then went to the website to get the installation instructions in PDF format. With the directions confirming how the setup should work, I setup a test rig...

It works really well! Since I have an event the next day, I am not going to bother trying to replace the speakers and fabricate a mounting for them. The existing 100 watt will work just fine.

The existing 300 watt amplifier can now be removed and as you can see with the pictures below, I gained a lot of space back...

Top view, showing the metal stand (heat shield) above the amplifier.


Heat shield removed, now to remove the 300 watt amplifier.

Look at all the free space!

Yes, the wiring situation is a bit of a mess!

After cleaning up that wiring mess, I used some L brackets and some FR4 G10 material to mount the amplifier board to.

With heat no being an issue anymore, I will be able to remove the cooling fan.

After testing various volume settings on the card, I found setting it to LOW wasn't quite good nor was high. However, through testing with the sound settings on the netbook, its working quite well!

A little detour to fix a door problem

2011-04-29T13:10:00.000-04:00

With all the time and work I have invested on the gripper claw, it quickly became obvious the door panel had a problem: It wouldn't open all the way. The door would rub against the skin and not open as widely as it should.

What happened? When the door and hinge were epoxied together, it looks like a clamp slipped off, pushing the hinge away from the door opening. As a result, at first glance, it looked fine but when I went to open the door and check the radius, I could tell the hinge was crooked.

Further complicating things was I had used a different epoxy. I used GOOP instead of JB Weld on these, since I have a love/hate relationship with JB Weld. For somethings, it works really well. For others...not so much, especially the Qwik version.

That said, I had to find a way to remove the GOOP adhesive. Being an epoxy, I found that toluene will dissolve and is suggested by GOOP to remove it. I went to my local hardware store since no one at the big box store had any idea or personal experience with the solvents. It was suggested I use a paste/gel type solvent, lightly brush it on, let it sit, pry a bit with a scrapper, then do a bit more in a few hours.

This is really, really nasty stuff so I did this outside, in the garage, with the door open.
(Incidentally, it seems EVERYTHING is bad for laboratory mice)

Once I had the door and hinge off the skins, I let them dry in the sun for a few hours. I need used the mouse sander to remove the larger residue. For the rest, I used the Dremel sanding flap to bring the surfaces to a shine yet rough enough for a good bond with JB Weld (later today).

As you can tell from all of these side tracking tasks, my R2-D2 hasn't moved to the new frame. With 4 events planned for May, I thought it best to leave things alone and working on the new accessories for my second R2.

So, if you have lost track of what I am working on...me too!

Progress will be focused on R2-D2 #2 now, maintaining my first one until #2 is ready to take over. Once #2 is up and working, I can come back to the first one, paint the blue pieces pink and do a complete upgrade and rebuild into the new frame.

(That plan may change in an hour tho!)

More on the gripper claw, prepping for the CPU Arm version 2.0

2011-04-26T22:46:00.000-04:00

Tonight I spent some time reviewing how to fit the gripper arm into the body so that it opens straight ahead. After a lot of adjusting, pondering and re-thinking....it looks like the best solution will be to remove the breadpan entirely.


The sides of the bread pan either rub the arm or the servo on the claw. The next step will be to attach the front skin and see how this alignment works without the breadpan.

The front skins are being worked on right now...trying to remove the crooked hinge still, so I'll have to wait a bit to check out the fit with and without the breadpans.

Meanwhile, I wanted to get the cpu interface arm dismantled so I could examine it...

Here you can see the original setup i had using plumbing pieces. In the foreground you can see the linear actuator I want to use.

It took a few good tugs with a set of pliers to get all the plumbing and tubing I had inside the cpu arm.

Next it was time to visually size everything up. It looks like once I hollow out the cpu arm a bit to fit the actuator, everything to go together fairly smoothly.

The trick, of course, is making a square piece fit in a round hole.

Always a challenge, this one.... (Yoda voice)

More work on the gripper arm

2011-04-25T22:09:00.000-04:00

Over the weekend I continued to make some progress on the arm assembly.

One thing that bothered me was how close to an inch of space was wasted trying to make a 1/4 20 thread fit into a 10-24 thread actuator. A coupler was required but I wanted to find something better.

By accident, I think I did!

I found a 10-24 thread grommet that had potential. I just had to add some holes for a 4-40 screw to pass thru.

The grommet is too small to reach the existing mounting holes, so I used a small, square-shaped piece of aluminum that would. Then it was creating two countersunk holes for the mounting to the claw, then two threaded holes for the grommet to be secured to. (No room for a lock nut where those screws go in)

As you can see, with the old coupler and mounting piece in the foreground. In an area that already has tight clearances, this helps a lot.

The next obstacle is the attachment of the linear actuator to the servo.

Ideally, you want the servo horn to be screwed into the servo. However, with the attachment pictured below, that's hard to do...


The L16 Linear Actuator includes mounting hardware, a U-shaped bracket and 10-32 threaded screws and lock nuts. I drilled a hole large enough for the bolt to go through the servo horn.

Now I can just use electrical tape on the bottom part for now and then the arm slides onto the servo fine. However, anticipating Murphy's Law, I would like to find something better. For now it will suffice.

And here is where I am at now, R2's arm assembly moves out, extends and the claw can open and close. However, the next step in this challenge is to have it going straight out, in relation to where R2 is pointed.

I was going to work on this some tonight but decided to address the issue with the door not opening all the way properly. This requires removing the GOOP adhesive since it dried crooked (clamp slipped off). As a result, the door is perfect at the bottom but as you go up, the hinge is falling into the body. I have some toluene solvent, which will dissolve the GOOP adhesive.

The one good thing about all this time in the basement has been my dedicated assistant, "Mokey". Anytime I get up, he steals my chair. When I am staring out in space, trying to find a solution to something, he's rubbing around my legs, desiring some of that attention. Gotta love a great wingman!

Dome pie panel mounted

2011-04-23T23:17:00.000-04:00

It took several tries to get right...and I wound up using the trusty hot-glue gun to find the right location!

2011-04-23T18:01:00.000-04:00

Here's a look at some of the progress I am making with the Gripper Claw addition to my R2-D2. Pardon the masking tape and electrical tape! I still have quite a ways to go to tweak this to run smoother!

More work transferring to the new frame - Dome Drive installed

2011-04-20T22:23:00.000-04:00

Tonight I did what I thought would be a quick installation of an AP Dome Drive into the JAG v5 frame.

What I am trying to do is instead of just pulling everything from one frame into a new, I am upgrading components I have been wanting to swap out. The dome drive was on the to do list since a better drive wheel had been developed.

On the JAG frame, there are pre-drilled holes for the dome drive to be installed to. You simply have to tap the hole to a 1/4 20 thread and bolt the drive in. The next step is to trim to drive shaft of the Pittman motor, so it will not interfere with the dome plate.

Easy, right?

Well...once I installed the dome drive, it was rather obvious that the electronics tray was going to have a problem...

I had two quick thoughts...move the dome drive mount a bit further right or move it to the front side.

The problem with the front idea was that there would be no place for the spring pin mount to attach. That space is taken up with the front door breadpans and then everything that mounts behind the large data port. (Translated = Bad spot)

So, I opted for moving the position over a few inches. The only issue with that would place it very close to where the shoulder mechanisms will be. To allow for maximum space, I drilled and counter sunk a hole for the bolt to go in from above where the piece is closest to the shoulder.

This looks like it will work out OK.

Next was to trim the Pittman drive shaft and bolt it into the mount. When that was completed, it was time to slide on the drive wheel and see how it fits with the rockler bearing and dome plate installed...

The good news is that the dome plate clears the drive nicely. The new silicone wheel material should be an excellent improvement over the older drive wheel that had a rubber band type material.

I like that the drive wheel has a nice engraving on it. The hex head screws may have to be replace with something more flush in the future. But, for now, it works.

Building this improved droid is teaching me something rather quickly....space is going fast. For this R2 to have the accessories it has now and additional one...is going to be quite the challenge!

Installing a hinge on the dome pie panels

2011-04-17T23:37:00.000-04:00

Today I have been working on installing a hinge on one of the top dome panels, referred to as the "pie panels".

When I first put R2-D2's dome together, I simply used some clear silicone to adhere the panels to the dome. I made the cut outs in the inner dome so I could come back to this in the future.

The particular pie panel I am installing a hinge on is the one that R2-D2's Life Form Scanner extends from.

With R2's dome removed from the body, I examine how much silicone I need to scrape free to release the panel...

I had to remove the dome power system, which consists of a fuse block and 12 volt battery. Once those I removed, I am able to slowly, carefully...and very delicately remove enough silicone for the panel to fall out.

Once out, its slow work removing the dried silicone.

The rest will be removed using a dremel sanding flap (120 grit). To protect the existing paint, I cover it with Painter's Tape and clean the surface.

Next up was to determine the fit and location for the hinge. I used some double-sided foam tape to find the best position.

The next step is to add some material to the hinge where it meets the dome panel. Since I threw away the inner dome panel when I cut them out, I had to make use of a scrap piece from the body skins. The extra material is required for proper alignment. I decided to use Super Glue, the Loctite brand that has a control gel formula.

Again, the most difficult part is the location, height and alignment. When I was happy with the location and moved the hinge around, I used the Super Glue gel, placed it on the hinge and gently laid it into position. I would have used JB Weld for this part but due to the awkward location, I wanted something that would set faster, allow me to test, then clamp into place.

Once the hinge was in position and had dried (I gave it a few hours to be sure), it was time to position the panel over the panel opening. With the hinges, you need to position the panel up a bit, so it can open smoothly and not rub the edge of the dome lip.

I used one of the cat beds to cushion, protect and hold the dome in position.

Now for the attachment to the hinge to the dome panel, I opted for JB Weld. Why? Because if I should need to remove the panel and re-position, I can do so. JB Weld is easy to remove, sand and clean up.

Tomorrow I'll check and see how well the fit is. If it works well, I can work on the servo installation!

Building a Gripper Claw Assembly for R2-D2

2011-04-05T23:55:00.000-04:00

A year ago, one of the R2 Builders was offering a replica of the gripper claw assembly. It was a really nicely done piece but I just didn't have the resources at the time to purchase one.

If you are not familiar with what that device is, this is a screenshot from The Empire Strikes Back, in a scene where R2-D2 is trying to grab a small lamp from Yoda...

Like most things with R2-D2...what a movie prop can do for a scene is very different for a real R2-D2. What's that mean? Well, finding the parts and pieces that can extend out that far, motorized and work as seen on the movie is a big challenge.

Several months ago, I stumbled upon an aluminum gripper arm & wrist combination. It strongly resembled the gripper R2-D2 has.

I found this Dagu Gripper Arm at RobotShop.com It has the servos pre installed and has one in the open/close mechanism and another for the wrist motion. Due to the fact the tall doors in R2 are 12 inches tall, to fit with an actuator, the wrist portion would have to go.

I found a Hub Adapter made my Lynx Motion (also from RobotShop) that would fit on the end of the gripper. The key to all of this working is the Firgelli L16 140mm actuator. With just under 5 inches of stroke, in the closed position it completely fits in the door way. Needed to make everything work together was something to go from the actuator to the claw.

The opening is a bit too large to thread with a 10-24 tap. The L16 actuator comes with a thread-on piece for fitting into 10-24 threads. Too get a snug fit, I had to drill this out with an #7 drill bit (13/64) and tap it with a 1/4-20 tap.

It was a real challenge to secure a round piece into a vice....but using a lot of WD40 and patient work, it eventually worked out.

The coupler I bough from McMaster-Carr. The female end is 10-24 and the male end is 1/4-20. I shortened the female side by 4 threads to shorten the distance up for a better fit.

With the coupler installed into the hub, the L16 actuator can thread in now...

Here is how it fits in the door-breadpan that mounts behind the front door...

Total cost is less than $200 and all you have to do is drill and tap one pre-existing hole!

Dagu Gripper Arm ($57)
Firgelli L16 140mm Linear Actuator ($80)
Lynxmotion Aluminum Hub ($8)
McMaster-Carr M-F Coupler Part # 92499A127 ($9.82)
$155 + shipping/handling/taxes

Uh-oh...Softpot fried...

2011-04-01T23:48:00.000-04:00

The Softpot Rotary potentiometer was working so well...then...poof!

It looks like the plastic stylus may have been forced too close and the ripped the sensor pad.

For the past several weeks I have been working on the software to read and work with the data. The progress has been slow but steady...then when I went to resume work one evening, noticed the data being output was very erratic. After removing the dome and checking the Softpot...well, you see the rips!

I did something a little different this time. Instead of ordering from SparkFun, I bought two replacements from TrossenRobotics. I was able to call them on their toll free number and immediately speak to a tech. The way they sell theirs, you can purchase it with a female connector already attached or bare, with the 3 male tabs exposed for soldering. They also include the coupler pins, so this time around, it will simply be a matter of plugging a servo cable in...no soldering tiny tabs!

Link: http://www.trossenrobotics.com/store/p/5604-Softpot-Rotary-Potentiometer.aspx

Replacements should arrive next week, then its a matter or carefully removing the old one and putting the new one in!

New frame assembly continues

2011-03-10T20:48:00.000-05:00

Over the past two nights I have been piecing together the new frame for my original R2. As I mentioned, it has been thru two owners before landing here and as a result, some pieces are missing.

Today the spacers and dowels I needed arrived from McMaster Carr. These are the spacers that go from the bottom frame ring to the bottom box as well as those that hold the utility arms. I also ordered some dowel pins.

The one oddity has been the block that goes on the bottom of the battery plate, where the center ankle connects. This isn't the original block, it doesn't even come close to the hole pattern on the plate. On the left is what came with this frame, on the right is what came with the original v5 Frame for my other R2.

The solution will be to use the correct one as a template and drill & tap the 1/4 20 thread holes needed.

Overhauling R2-D2 begins

2011-03-07T21:44:00.000-05:00

Today, the v5 JAG Frame I bought from another builder arrived today. This is identical to what I bought for my second R2-D2 project.

The frame is missing a few minor pieces, such as some spacers and dowel pings, but nothing I can't replace locally or on-line via McMaster-Carr.

Here's a bunch of pictures showing the assembly process from tonight. More soon!

Here's what a JAG v5 frame looks like un-assembled

Bottom plate, the holes on the bottom have already been countersunk

Threaded studs in the front and back, side pieces bolted in.

Long vertical rods are in

Side pieces are in. The big trick here is to make sure the shoulder stops are facing the right way

Top ring in

I saved one of these when Jerry offered them....fold out electronics tray for the frame


Mostly assembled now...

I haven't decided how "quickly" I will try to move things from my existing R2 into the new frame. The electronics portion will be the most intense part. But, I may just take my time making sure I have a good plan thought out before doing so.

Tomorrow I'll work on the rest of the frame, getting the battery holder installed with the correct spacers.

Benefit for Don and Dora Winslow

2011-02-13T19:40:00.000-05:00

Last night was the fundraiser benefit for Don and Dora Winslow. Don used to be the Chief of Police here in Bangor and his wife Dora worked for the hospital. Recently they were each diagnosed with cancer and their many, many friends wanted to do something to help. The result was a huge benefit at the Morgan Hill Event Center in Hermon. Many fantastic items were offered for auction and over 400 people came out to show their support and donate.

When the event was first announced, I offered to bring R2-D2, if they would like us there. I have had many, many emails from people asking when R2 would be available outside of the hospital. Since I keep to only charitable functions, this seemed perfect. I checked with the organizers and they were thrilled with the offer.

One hurdle was getting R2-D2 out of the house. We have had several consecutive storms that left 4-5 feet of snow in the front yard. Further complicating things, the snow blower died. (The mechanism that engages the auger has sheared off.) It took about 4 hours to shovel out a path wide enough to the front door. The real challenge was by the roadside, where the wet snow had frozen solid, into ice. Where's a light saber when you need one?

Once there, R2 mingled with the public and posed for a lot of photos. I was amazed at the reactions, many had seen us on television or read about us. Since this was an adult event, it was really neat to see all the girls hug and kiss R2-D2! (R2 was also in high demand once the dancing started!)

Dora and Don Winslow sharing a dance

Sarah and R2 get their groove on

Sensor installed in frame, R2 is seeing data!

2011-01-29T23:01:00.000-05:00

This afternoon I relented a bit and made the changes on the original frame for this bracket to work on. I really, really want to see this sensor working!

In order for it to work, I had to bore out the hole in the top frame ring. The newer frame already has a properly sized hole to accommodate the slip ring electrical connector. In the old frame, we aren't going to mount the slip ring to it, but we need that hole there so that the bottom piece of it. This way the all the wiring can pass thru.

I had to drill the hole with the frame ring mounted in place. First, it wouldn't fit under the drill press. Second, to remove it would require removing the skins, which would require a lot more things to be removed, such as the legs and so on. What I did do was use some old t-shirts I have to cover everything below. We do not want aluminum debris showering down on all the electronics.

After carefully wiping the aluminum debris off, I wrapped up that t-shirt and tossed it in the trash, then replaced it with another.

Next up was taking the aluminum bracket piece, marking, center punching and drilling out the holes. Since the frame piece it is going onto is so thick, I am drill with a 3/32 drill bit then tapping a 4-40 thread into it.

Next up was the lexan piece that the Softpot sensor would adhere to. I did some initial measurements and it became clear to me that I would want to add a second piece of lexan in there. With two identical pieces, the height would be just right for the stylus piece to make contact.

I clamped the lexan pieces together and drilled a hole on each side and into the aluminum bracket. The lexan pieces were drilled again with a 1/8th inch bit and the top piece countersunk for a flush mounting. The holes made in the bracket were threaded to 4-40. Once tapped, the lexan mount was secured into place.

The next step was sticking the Softpot onto the Lexan.
Using the slip ring as a guide, I removed the paper backing and slowing lined up front to the center front of the frame. It needs to be centered well for the stylus to track around it, much like a stylus does on a record player!

Now a real fun challenge!
The stylus for the Softpot is METRIC. I do not have ANY metric drill bits or taps. The best I could do was approximate the 6mm threaded stylus into Imperial. I checked a few references online and found 15/64 is very, very close. However, the closest I had was 7/32 and 1/4. 7/32 was a tad too small and 1/4 was a smidge too large. So, we went with 1/4!

As luck would have it, I could not find anything thinner for a 6mm nut. I did find a piece that would allow it to thread thru for additional support under the dome ring. Set up the way it is, I can adjust the height the stylus is set to by holding the nut and turning it with a (blade) screwdriver. Again, like with most things in the project, it isn't perfect and I am sure it will be refined again and again!


The stylus has a spring loaded plastic nub to make contact with the poteniometer. As the stylus goes around the piece, the voltage value changes. The ServoCenter card receives this analog data in 8-bit and 10-bit streams.

The big moment! Plugging R2-D2 into the computer and seeing the data come in...

And it works....in the red rectangle, the values change for ADC0 as the dome is rotated around. Several things will have to be adjusted for in the software as the values are reading in reverse. I also need to trim the values some so that a zero value can be dead center. These aren't hard to fix, it will just take some trial and error to get right.

So another hurdle leaped! Next up....writing the software code to establish the position of the dome and moving it around under computer control.

Trimming and drilling out the dome position bracket

2011-01-24T21:45:00.000-05:00

Tonight I did some more work on the aluminum piece that will mount on top the frame and hold the lexan piece.

My scrap piece isn't a perfect rectangle and for what it needs to do, it really doesn't need to be. At some point I'll want to refine the piece but for now, I just want functional for testing.

That said, I used my trusty Dremel 4000 and trimmed down the aluminum to be just a tad bigger than the lexan.

I took the piece and placed it on the newer frame, which has the bolt pattern for the slip ring to mount. The slip ring will not mount onto this but since the holes are already cut into the frame, this makes bolting it to the frame that much easier. I drilled out a 1/8th inch hole, which will allow a 4-40 thread bolt to pass thru. I then used a counter-sunk the holes so that the head of the 4-40 bolts will sit flush.

Here's how the piece looks on the newer frame. The pre-drilled holes in the frame are larger than the 1/8th inch holes i drilled. A washer and nylon-insert lock nuts will make this a snug fit.

If you are curious why I haven't modified the original frame for this, here's why. I plan to acquire another newer-design (JAG v5) frame and transplant everything from R2 into it. Not only will there be some significant weight savings, but now both droids will be identical in structure. Should I need to inter-change parts & pieces, they'll fit!

Next time, I plan to do some work on the best way to mount the lexan to aluminum bracket.

More work on the dome sensor mount

2011-01-23T21:54:00.000-05:00

Post number 300!

I wasn't completely satisfied with the circular piece of Lexan I had cut out last time. The inner hole was sloppy and I knew I could do better.

Once again, a trip to my local Lowe's. This time I bought a PVC/Metal hole cutter, which has a much less aggressive cutting tooth than a regular hole cutter has. The inner diameter is 1 inch and at a cost of $7, it was one of my cheaper trips to Lowe's in quite sometime.

After making another 3 inch circle in Lexan using the Dremel, I clamped the piece into the drill press and using the circle cutter. Since the circle cutter has a drill bit in the middle, it lines up on the center hole used to cut the circle, making the job quite easy.

It took me a long time to decide what I wanted to mount the lexan piece onto. Another piece of plexi? A thick piece of aluminum? I opted for aluminum since I had a small scrap piece I think will do the job.

Going very slowly and with a generous amount of WD-40 to lubricate the hole cutter, I drilled a perfect 1 inch hole into the aluminum.

Here's what I have...


Electrical Slip Ring, Aluminum mount and Lexan Softpot mount

The slip ring, has to fit through the center since it will be mounted above this assembly.

As you can see, the slip ring will fit with a bit of room to spare. Excellent.

Next up is trimming the aluminum piece a pit, mounting the lexan onto it, then the block onto the frame. Once that is in, we can fine tune the installation of the stylus.

Starting work on the dome position sensor

2011-01-12T21:45:00.002-05:00

Tonight I began working on one of my ideas I have had to mount a dome position sensor inside R2-D2.

Here's a graphic of how it should work...

Essentially I need to craft a way to mount the sensor on top of R2's frame. It has to be tall enough for the stylus to reach the Softpot sensor, which is mounted on a piece of Lexan for best adhesion. The inner hole needs to be large enough for the slip ring electrical connector can pass thru.

First I will make a circular lexan piece for the sensor to come to attach to. I decided to use my new Dremel 4000 with the circular cutting gadget I've had for years. I also bought a better cutting tip which will work well with plastics and metal. Here's the photos that detail the process...

Once the paper backing is removed from the sensor, the sensor will not appear to take as much of the lexan as it does now.

I took the lexan piece and placed it on the top of R2's frame so I can see how tall the mounting will need to be...

This gives a good perspective of the challenge. The center-spar like section of the frame shows, the lexan piece and above is the dome plate.

Tomorrow I am going to resume work on a mounting piece to go from the frame to the lexan piece.

Recognized by Eastern Maine Medical Center for our Pediatric visits!

2011-01-08T19:23:00.000-05:00

I was very surprised last Wednesday to have the CEO of EMMC and many others from management award me (and R2-D2) the "Splash" Award, which is our company's highest honor.

I have the rare honor of loving what I do for work....and what I do off the clock...at work!

Here's the award....

Huge KUDOS and thanks to my fellow R2 Builders who have helped me along the way! From those who produce the parts, to those who were able to answer my many questions and those whose blogs/tutorials gave me guidance during the build and upgrades!

Repairing the CPU arm

2010-12-21T20:07:00.000-05:00

Well the CPU arm is having some issues.

Where it mounts to the large-scale servo is a bit problematic. The arm has an L bracket on it, which then bolts on to the metal servo horn. The arm has worked well for weeks but since the attach point is one bolt, it was a matter of time before is loosened.

Here's what happens..as the arm got loose, its more difficult for the servo horn to lift it/hold it steady. As a result, this gives the servo feedback and it begins to twitch.

Tonight I removed the cpu arm from the servo horn to draw out some ideas...

I've actually thought of a few ways to re-do this with a linear actuator. That would replace the car power antenna, which is taking up some valuable space.

However with the R2 fund being what it is (Ha, can you say *zero*?), I will have to see what I can do to tweak/repair the existing setup.

Back to work!

Rollerblade wheels installed and working

2010-12-20T19:10:00.000-05:00

Today we continued the work of installing the rollerblade wheels into the center foot.

However before that, I wanted to put R2's center foot on the scale and see how much weight is being placed on it....

Center foot gets weighed in...


There it is...94 pounds.

There's just under 100 pounds of weight being supported by the center foot. The casters I have been using are rated for that and more yet we're still grinding the bearings and wearing the wheels out.

Here's a comparison picture of the casters that were mounted in there with the new, replacement one sporting rollerblade wheels...

...and just before being installed...

I made a video blog entry that shows the result...