Ramping causing gear skipping

Gears are skipping in the WCP flipped gearbox attached to two Falcon 500s. We have motor ramping done by Phoenix slew rate (configOpenLoopRamp). We replaced the belts on the right side and nothing works. Before, the ramping was 0.6 along with brake mode. Now if we set the ramping below 1.5 it’s instant brake. We replaced the whole gearbox and it still skips the gears.
Picture of the right side:

Picture of the left side (this side works partly):

My code: https://github.com/JaiCode08/4065-2023-code
Everything worked before we replaced the belts on the right side. If we change the direction too quickly the gears skip (both sides). This problem also didn’t happen before. Thank you for taking your time reading this.

EDIT: I ran the code in simulation and the ramping works with 1.5 but it does not work with anything below it, this is super weird. Anyone have any idea what’s causing this?


Is it the pulley skipping or the gears? If it is the pulley I would recommend switching to 35 chain

Well your gears look like they’re in decent shape, so if those are skipping I’d look at the gear spacing. If f those are COTS gearboxes double check you are using the right gears, if they’re custom double check your spacing are gears.

If there’s any chance it is something else that sounds or looks like gear skipping, check for belt skipping and consider a chain (we use #25 without issue), go through the whole drivetrain step by step looking for wear.

If those are 9 mm wide belts they may not be adequate for a west coast drive application. 15 mm wide will work, but I have heard people have issues with 9.

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I didn’t know why our team uses 9 mm as I am a programmer but everything worked fine before we replaced the belt.

We had a problem with gear skipping, tensioners worked, but eventually we switched to chain. I don’t know how easy or possible that would be for you though.

I saw my coach talk about it and we might be switching over. I just hope that the drivetrain performs as it did before, we have a regional in 3 days :grimacing:.

We got ours all swapped and finished in a day or two, if you need a quick fix then tensioners are the best bet without swapping anything, but chain or a different belt should work well if you are able to swap in time. We use 25 chain like Patrick3357 mentioned.

I still recommend switching to chain, but to get the belt working you could loosen the 10-32s in the bearing block, put a clamp on the axle, and on the frame perimeter, and tighten it. Put all 4 10-32s in the bearing block so it does not shift. Make sure the 10-32s are very tight. Also are there lock nuts on the bolt? I cannot tell from the picture.


Those pulleys are way too small for those wheels, especially with 9mm belts.

Update: swapped to chain and works really good, thank you!


I’m glad!

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