Diagnosing Belt Skip Under Load

[Joey Milia]

The problem is definitely at the small pulley. It's not simply supported so I wouldn't be surprised if the position of the pulley flexes a bit under high acceleration, not much you can do about that though. I'm assuming you're using the VexPro htd belt.

Things that would help:
1. Switch to 24t pulley. Would slow you down a bit but probably not super noticeable, you're pretty fast already.
2. Switch to GT2 or GT3 belt from sdpsi.
(Edit: scratch that one. GT series are better with power but HTD might be better with shock loads due to deeper profile. Don't have personal experience on that. Jury is out)
3. Limit your acceleration in software. Even a small ramp will help enormously. This is probably the best option as you don't need to buy anything else and will probably make the biggest difference.

Higher tension would probably help with the skipping, but may not be the best solution (depending on how tight things are already)