We have an 6 wheel H drive - 4 Omni wheels for forward/backward motion and 2 Omni wheels mounted in center for strafeing (sideways movements).
Our strafe wheel rollers siege up after about 2-3 weeks of high usage (as it is competition season). The new wheels perform excellently. We are now on our 3 set of wheels for the strafe motor. The issue is when this happens, our robot either moves very slowly in forward/reverse directions or unable to move at all. After investigations, we determined that the rubber rollers get soft and start stretching and then get stuck as it folds. Is anyone else facing this issue and are there any solutions we can implement? We checked the leveling and all wheels are even on the floor/mat. Picture of our frame and the worn out rollers on strafe wheel below.
That’s what we are doing. We are now on 3 set of wheels. And no - pictures are of wheels purchased couple of months ago. It was Ok it happened with 1 st set as it lasted couple of months. The second set lasted 2 weeks of competition season.
This is the same thing that happened to our wheels at worlds last year. One thing that I notice is that having those strafing wheels are preventing normal turning. With a single strafing wheel this would not be a problem, but since you have 2 wheels it is. Whenever you turn it is pushing against both of those wheels since they are being forced to move in opposite directions, this is most likely the reason your wheels are getting worn like that.
Thanks ! this is definitely the problem - Going to a single strafe wheel is not an option when our bot is performing very well otherwise and also to balance the load and stabilize the overall system (we are a 9 block stacker). We are thinking of replacing the one of the strafe wheel shaft inserts with a round one so it moves freely
Thanks for the great post and for sharing your pictures.
Are the motors driving the green wheels set up so they can free spin or do you have the locking/hold function set on them? It looks like you have huge wear on one of the rollers and not as much on the others. You would get that if the wheel can’t rotate and it’s forcing the roller to drag.
We have a very similar set-up (2 strafe wheels, previously 3), turn frequently, and have never had these problems. I think that you must just have old deteriorating wheels.
We initially had locking set for precision- after we wore out our first set of wheels, that was the first thing we got rid of in code.
For the second set, I think we had the locking reintroduced for just few runs, when we started noticing the same problem of robot slowing down and the front/rear wheels slipping. Also the second set has only couple of rollers worn out and the robot was still able to move move forward although slowly. So it could be that locking is main problem, but can’t believe few runs with locked wheels would wear out the rollers so fast.
Also a clarification - we only lock the motor for straight forward/rear motion and unlock it for turning and strafeing.
the robot in the pictures look pretty compact, the grey omni wheels might be a little closeto the outside of the robot and the chain looks pretty close too
and also to balance the load and stabilize the overall system (we are a 9 block stacker). We are thinking of replacing the one of the strafe wheel shaft inserts with a round one so it moves freely