Friday, November 27, 2009
R2 Goes to Sam's School
On Wednesday, just before Thanksgiving, I took R2 over to Sam's preschool to see all the kids. They were very excited. There seems to be a short or something going wrong with the sound system. When I would press the button for one of the sounds, I'd get an amperage spike and the sound would cut off short. I turned the sounds off for the visit until I can investigate the problem:
The motors are still running weak. I think that on one of my very first tests, I pushed the left motor too hard and damaged it. Every since, its response has been sluggish. I am eager to get more reliable, responsive, and higher torque motors in there. The answer is a set of the NPC 2212 motors from NPC robotics. And I think I am going to build a Senna style drive train (the files are in the files section of the Yahoo group). I've been searching around for some cheaper parts alternatives. The Surplus Center has all the gears, axles, chains, and extra links that are in Senna's plans. Mike got his from McMaster Carr, but the Surplus Center options are much cheaper. And since they have keyway slots already cut in them, there's no need to buy the keyway broach cutter for the project. So I think I can save about $150 on the project, which is substantial. The keyways are little slots that have been cut into the axles and into the gears. When you slide the gear onto the axle you then put a small strip of metal into the slot and it locks the gear to the axle for the power system to turn it. That will be the next project after these two sets of legs are done.