Intelliquilter Motor Pulleys and belt.
If you have the Intelliquilter Supermotors with the clear motor belt, then no doubt your belt will stretch, yellow or perish at some point. This will result in obstruction errors that can be very frustrating.
Zoltan has created an upgrade to new motor pulleys and notched belts, that are even more accurate and longer lasting than the clear belts.
The following video is to assist upgrading your motors yourself.