wIndependence Parade Float
In honor of the first annual wIndpendence day (as declared by the Desktop Linux folks), and to help spread the linux message to the masses, I am building a parade float for the annual Potwin Place July 4th parade. Combine a few sheets of plywood (and some other supplies) from Home Depot with the guts of a retired BattleBots combat robot, add some bits of cardboard & paper-mache to make a 6' tall Tux, and I figure there's a Desktop Linux wIndependence day prize with my name on it! Besides, all the neighborhood kids will think I'm cool (as if the whole BattleBots thing didn't have that effect already :-).
BTW: Potwin Place is a small Victorian neighborhood in Topeka, KS (mainly built in the late 1800's), and happens to be where I currently call home. News-Flash: See the Potwin mayor on the cover of the Topeka paper.
June 28, 2002: It's a box!
After almost 1 week of construction, I have a plywood box. Not a lot of progress, considering I bought the plywood almost a week ago, but I came down with a nasty summer cold and was sick most of the week, even missing work. I probably only have about a half-day of real work at this point, spread out over many days. Hopefully the rate of progress will increase now that I'm feeling better.
June 29, 2002: It's a box with a wheel!
Well, after a good solid day of work, things don't look a lot different, but there is now a front wheel. Actually, an amazing amount of planning, measuring, and general problem solving has been done, and it takes longer than you'd think to work out a steering mechanism, even for a tri-cycle gear with only one steer-able wheel. BTW: That's a lazy-susan bearing I'm using to support the front wheel. So far it's worked pretty well.
June 30, 2002: It's mobile (sort-of)!
Lots of progress today. Yesterday I managed to only get one wheel added...today I got two more, *AND* I even got the motors hooked up. If you're wondering, they are Baldor industrial servo motors (about $750 each), and will be driven by one channel of my Baldor motor driver (the big mass of electronics). I'd like to have both channels for drive, but one is still fried from my latest BattleBots adventure. :( The motors & controller are really designed to be run off of about 150 Volts (rectified AC), but they seem to run fine on the apx 50V I'm using here. You can see the battery packs (the two large white lumps in front of the electronics), which are built up from 3000 mAH NiMh RC car packs (4 6-cell packs in each of my 28.8V battery packs). In BattleBot configuration, I used to use 4-6 of these packs in series (for high voltage), but now they've changed the rules, so you have to go with higher current, lower voltage stuff <sigh>. Anyway, the 3000 mAH capacity should get me through the parade on one charge, the fairly low-voltage shouldn't affect much...I can still go way faster than the parade speed, and the motors have lots of torque (did I mention they're industrial servo motors :-) ...plus, the battery packs are small, so I'll carry some extras "just in case".
The rear wheels are still not bolted to the box frame, but "push-tests" up & down the alley (prior to mounting the heavy motors on the wheel carriers) were a lot of fun. The only "problem": high-speed turns will cause the front corners to dive, potentially even hitting the ground. Given the expected pace of the parade (small children on tri-cycles can easily keep up), I doubt this is a serious issue :)
July 1, 2002: It's Alive!
I didn't get a lot done today (I had to run the last of our 5K race series), but I did manage to get the rear wheels mounted, and the motors wired up to the controller. After hooking a couple batteries up with clip leads, I headed down the alley to terrorize the neighbors...sadly, my batteries gave out at about the end of the block, but it was still a lot of fun. Now I need to do some tests with fully charged batteries...hopefully I won't need to carry too many spares, but I can always beg, borrow, or steal four car or motorcycle batteries if I need *LOTS* of juice.
Only two more days to go, but I can finally start working on Tux!
July 2, 2002: Hijacked!
No pictures (I forgot my camera at home)...check back later.
Today I hooked up and mounted all the electronic bits, then did some test driving around the neighborhood. This may have been a mistake, as not only did I loose a lot of time driving around, I picked up a couple the Teeter's two youngest boys, who quickly decided they wanted to ride my float in the parade, and that a July 4th float should *NOT* have a penguin on it. Being out-voted 3-1 (my wife mutinied and voted against me), and rapidly running out of time to make a presentable tux, I may have to give in to the inevitable. I'm still planning on swinging by Home Deopt tomorrow, to see if I can find anything that can be turned into a respectable Tux in a few hours...I figure if they can do the Trading Spaces thing in two days, I should be able to build a Tux in less than an evening! :-)