Robot does not travel straight


#1

Hi, Now that all my previous problems appear solved, I put the GoPiGo on the floor and reran the Demo. I had to reposition the battery pack from the rear deck up to the canopy because it could not get traction. Now that there is weight over the wheels, it gets traction and moves. However, it moves in a clockwise arc (curves to the left) and retraces that arc in reverse. Any ideas on what may be causing this and how to straighten out the route?
Thanks.


#2

It sounds like one of your motors polarity is reversed. Turn your GPG upside down and send it a forward movement command and notice if the wheels are both turning in the same direction.

Good luck


#3

Thanks, but that is not the problem. I tried reversing polarity on the outside wheel, but the robot then spun in a very tight circle. because my arc is about 3 feet long, I can only surmise that the floor must be slippery in spots. guess I will have to try it out elsewhere. Thanks


#4

Hey Larry,

Great question! I haven’t seen this one in a while. This might be because of a minor difference in the motors. More likely, as you point out, it’s slipping. If you feel like the wheels are slipping on your surface, we’ve found that a rubber band around the rubber wheels (like one of those white and wide ones) can help you get better traction. Putting the same thing on each wheels will yield the best results.

If that doesn’t solve the problem, let us know; there’s a way to trim the wheels specific to your board we can walk you through.

John


#5

Hi John,
The problem has been resolved - it was mismatched motors. I replaced the motors from the original kit with the motors from the replacement kit you sent me. Now the robot moves in basically a straight line. There is just a little jiggle near the 3/4 of its path and I put that down to the surface.


#6

Hi larry,
Glad to hear that it worked for you. Can you describe a bit more about the mismatched motor. Was one of the motors running a bit slow or was there any other problem with it.

-Karan