Version 1.5 of AlphaPujo (AP) got beat up pretty bad at BotBash. After looking at the damage (most of which was dished out by HyperActive), I decided to do a full rebuild.
The first thing I had to decide on was which motors to use for the new build of AP. After looking at several possibilities, I choose the Handiwork drills. They seemed to have a good balance of weight, torque, speed, and size.
Mounting the wheels to the motors proved very simple. I used a 3/8" tap on the surplus wheels I was using, and just screwed them onto the output shaft of the gear box. These are the same wheels I used in the earlier versions of AP.
Since the Handiwork motors were considerably heavier then Barber-Coleman motors I had used before, I decided to go with 3/16" aluminum. I had used 1/4" aluminim on the previous incarnation of AP.
After laying out the basic design down in a CAD program, Ted and I machined the frame components in about 3 hours. The aluminum frame was machined, everything else was made in the garage with much simpler tools.
Here's a early fit test of the various components. It looks like I'll have all kinds of room. The Vantec makes a return. It's probably overkill, but it's what I have.
I made some corner braces out of 1/2" polycarb. These provided something to bolt the base and top plate into for the corners.
Here's the baseplate and motors mounted.
Not much is mounted internally, but I wanted to to go for a test run. I'm happy with the speed and traction I'm getting.
The batteries I originally planned on using couldn't source enough current, so I ended up ordering a few Battlepacks. These worked great, and gave me aroung 6 minutes of non-combat driving time. They weighed about 6 oz less the original batteries!
The batteries, Vantec, and motors get pretty warm after six minutes, so I hooked up a few fans to keep things cool. The fan up front pulls air in, the air is directed over the interesting components, and exits the rear of the bot.
In order to eliminate the 4.8V receiver battery pack, I picked up a 5 volt regulator at the local electronics store. In AP 1.5 I had used a Team Delta BEC, but Dan doesn't sell one for low voltage systems.
For an on/off switch, I made a removable link out of two Anderson connectors. The link requires a LOT of force to remove.
I decided to try a Biohazard style side skirts. Here I've attached them, but not cut the angle.
I tried eyeballing the angles, and got relatively close. There's a small gap, but it's not too bad.
Here's the final glamour shot.