Robot not turning well?

I have a 22.6 pound robot with 4 inch Omni Wheels (2 on each side) connected by chain on a 2:1 Ratio powered by a total of 4 Standard 393 Motors. My robot is easily accelerating around the field without stalling out, but is having trouble with turning in place. It always appears to be putting a lot of stress on the chains when turning and does it very slowly. It doesn’t stall out, but it just seems like its not performing to its maximum potential. My robot is a Single Flywheel Shooter and the side with the launcher is pretty heavy, making the center of gravity about 12-13 inches from the front. Can anyone give me small tips or suggestions to help me make my robot perform better? Any help would be greatly appreciated :slight_smile:

Could you post a video of it turning? We had this issue once because our drive motors were at the top of our robot and the angle we tried to drive the wheels at was leveraged weird. Also, is your flywheel spinning when you are turning?

We’ve seen this a number of times with Omni’s. The robot is so heavy that it sinks into the mat and the omni ‘barrels’ can’t turn sideways, only drive in a straight line.
You can add another pair of omni’s, 6 total. The extra 2 do not need to be powered but drop the PSI on wheels.

I can later, In school currently. I haven’t noticed a difference in turning with the flywheel powered vs unpowered.

Good idea!

We have seen robots able to turn but not drive straight when the motors are not string enough to drive it. But it sounds like @TriDragon has a good idea here. Doubling the width of the wheels would be another option to add surface area but a little space in between the wheels is needed to make the rollers still roll. You probably don’t have the width to do that.

The extra wheel does not necessarily need to be driven either. You could just have a free spinning wheel just to alleviate the pressure per square inch on the mat. That size of a free spinning wheel could be a smaller one if necessary too.

I don’t believe triDragon meant adding the wheel next to an existing one, he meant put it in between the two existing wheels, making a standard six wheel base.

Also make sure the omni wheels are not broken. The 4 inch omni’s hubs are weak and cracks easily. We had two hub shattered the day before our provincial. Thank god our sister team has two extra. Also check the individual roller to make sure they are intact and rolling smoothly. We had 4" omni rollers that self destruct after a day of competition. We have now switched to 3.25 inch omni.