Today, we got our robot going, set it down to drive, and well, it dind’t. What happens is that the bot will move about 6 inches or so and then the 40 amp curcuit brakers will cut off. We have tried checking all of the connections for binding, greasing everyting, etc. We are running the drill motors through the supplied gear boxes directly to 8 1/2 in dia. wheels. We have a chain connecting the drive wheels to the rear ones to form a 4wd system. We have also tried removing the chain to make it a 2wd system.
Scooter,
Does the robot run when you lift it off the floor? If it does then your wheel axle(s) is probably binding. Since you are using the drill motor transmission combo, is the trans firmly selected into one gear or the other? Start with the simple stuff, disengage the drive wheel gear from the rest of the drive system and see how easy it is to turn the wheels. If that seems OK then see if you can drive the drill motors without being connected to the drive wheels. If that is OK then the gears are not meshing right. I suspect you will find a mechanical problem is the cause if you are using the supplied FIRST drive system. Many teams have reported over tightening causes the parts to crack.
Let us know what you find.
We’ve been having a lot of problems w/ our transmission too. I think almost everyone on the team knows basically how to change it b/c it messes up SO much.
Air is the problem…or lack of it…or is it lack of power??
We’re using pneumatic cylinders to shift our two speed transmission. The cylinder is controlled by a single acting solenoid valve. When power is removed, the cylinder will return to its original state. Therefore, if we are traveling 13ft/sec when the control power is interrupted, the transmission will shift into low. NOT GOOD. We therefore changed the solenoid valve to a double acting type to eliminate any problems.
Another thing to all teams…Make sure you are checking your mechanical connections very well after every match. This years game is very physical and the playing field is very stressful on your machines. Bots will experience significant vibration as they travel over the ramp, especially if they have a fast machiane. Our students have been running our robot around during the last few days for hours at a time, catching air over the ramp, destroying crates and basically pushing it to its limits. It has really held up very well except of some lose connections. Take the time after every match to go over your machine and check your connections.
