Extreme curve?

[logank013]

Disclaimer: Not on the manufacturing team.

But check the code. Is one side driving faster than the other in the code? If so, try boosting the left side to 80% and the right side to 70%. Just adjust so the system drives straight, even if the code says it shouldn't (straight might be left 90% and right 60%. idk, robots do odd things.

Also, by some odd chance, does your left side have a higher gear reduction? could your gear boxes have been built just different enough?

[MetaEngineer]

The number of parts in a typical FRC drivetrain can make for a noticeable variation in the speeds of drive units. When run open loop, the drivetrain on our bot this year has one side a few percent faster than the other which made it curve.

Certainly calibrate all motor controllers and double check connections first. You may be able to tweak your drive train for better consistency and find a balance of motor power settings that goes approximately straight, but the real solution is using some form of feedback. A combination of wheel speed encoders and/or a gyro lets the roborio make adjustments on the fly. However this can take a fair bit of time to get coded and tuned in properly.

[wsh32]

If you do have the time, I would advise using the gryo to make a feedback loop to keep the robot going straight. If tuned properly, that should make the drivebase drive straight regardless of any mechanical issues.

[AustinSchuh]

Originally Posted by logank013

Disclaimer: Not on the manufacturing team.

But check the code. Is one side driving faster than the other in the code? If so, try boosting the left side to 80% and the right side to 70%. Just adjust so the system drives straight, even if the code says it shouldn't (straight might be left 90% and right 60%. idk, robots do odd things.

Not to pick on you directly, but this is a convenient quote.

I'd caution against ignoring the issue or papering over it, and instead start to look for the root cause. If the issue is that a motor isn't plugged in when you thought it was, or the speed controller was disconnected or a mechanical issue, fixing it in code will make it look like everything works when it doesn't.

The current suggestion is a good one. After that, I'd try isolating the issue. Feel each of the sides of your drivetrain and try to see if one side has more resistance than the other. Try unplugging all but 1 motor per side and see how it performs. Do that for each of the motors on a side. Try controlled experiments to see if you can discover where the problem is.

[Ether]

Originally Posted by AustinSchuh

I'd caution against ignoring the issue or papering over it, and instead start to look for the root cause... Try controlled experiments to see if you can discover where the problem is.

This needs to be shouted from the rooftops.