Wednesday, May 18, 2011

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

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!