Sunday, February 16, 2014

Working on R2's Life Form Scanner

(Note:  I seem to be cross posting about the lifter mechanisms on both of my R2-D2 blogs, so I apologize for that confusion!)

The Life Form Scanner has many names.  Some call it "the mini radar dish" R2-D2 uses in THE EMPIRE STRIKES BACK.  Here's some screen shots...

Now thanks to the talent of the R2 Builders Club, we have Life Form Scanner machined in aluminum  Here's how the base pieces look like when it arrives...

The challenge is making all of these separate pieces interlink, since by design, they do not.

First, the top most piece is called the "cap", which is where the screen mounts into.  The bottom of the cap has been drilled and tapped with a 10-32 thread.  The next piece down, which I will simply call the "top", already has the hole in the top.  To allow it to connect to the cap, that hole is also tapped to a 10-32 thread.  Now a small 10-32 machine screw, with the head cut off, can thread in.

The top piece has two holes, one on each side, as a means to route the wires that connects to the screen.  As the screen shots show, the movie wiring shows curly/spiral type wires going to the screen.  I have searched high and low for super thin, spiral wire like that.  I couldn't find anything even close so opted to go with 22 AWG solid core wire.  With solid core wire, I can wrap the wire around the shaft of a screw driver and create my own coiled wire.  But that will be the last step before attaching the wire to the lighting, since the holes need to be widened out a bit for the wire to fit.  Using a 3/32 drill bit, I can easily get the wire to pass thru now.  

Here's how the bottom of the top piece looks from the bottom, showing the wires (test wiring!) as they pass thru...

As you can see, with the wires there, that rules out having one long threaded rod go thru the base pieces...the wires are in the way.

The bottom piece has a hole already in place for the wire to pass through.  However its too small for two wires.  The hole is too far to the side to allow for it to be widened, so I added another hole on the other side.

My strategy is going to be this...get the white wiring in place, crimp on a female connector, use white shrink tubing to seal it up then spiral the wire before attaching to the screen.

I make sure to note which wire will act as POSITIVE by putting some blue tape on each end after it has passed thru.

The white 1/16 shrink tubing goes on first, the wire is stripped back a 1/2 inch and the female connector is crimped on.  The shrink tubing is pulled over the connector and using a lit match beneath it, the tubing shrinks.  The connector slips onto the lighting prong.

Now the delicate work of disconnecting the connector from the lighting and coiling it up around a screw driver.  This gives that coiled look seen in the movie screenshots.

The lights only take 5 volts so I used an R/C receiver battery to test the wiring and lights...

I found an old cell phone charger that had a black spiral cord, which I can use for the bottom section...

After some delicate soldering work, the scanner wires are connected to the black spiral wire...

I think the bottom part of the wiring needs some more work to better resemble the movie screen captures...but this is good enough for today.

I also applied some silcone adhesive between the top and bottom piece.  I need to secure those two sections together.  This way, when the servo rotates the scanner, the entire assembly moves as one.