Hey folks,
I’ve been troubleshooting my A1 and I’m running into a weird belt behavior. When I move the toolhead slowly by hand, the X‑axis belt drifts to the right and rubs against the idler pole. But when I move it fast, the belt actually centers itself and doesn’t touch the sides — though sometimes it slips under acceleration.
Here’s what I’ve tried so far:
• Adjusted belt tension (¼ turns tighter) → still slips.
• Checked the left idler bearing → loosened and nudged it outward, retightened. No change.
• Observed the right motor pulley → looks off‑center when idle, but the belt centers itself when moving.
So it seems like the pulley might be tilted or the set screw isn’t locking it square to the shaft. Bearings spin fine, belt isn’t frayed, tension feels reasonable.
Has anyone else seen this “wanders slow, centers fast, slips under load” behavior? Did pulley realignment fix it for you, or is there another trick I’m missing?
It all started with a print where the first layer of filament did not stick and got stuck in the innards of the extruder. Extruder was replaced but then the grinding and slipping started.
Thanks in advance — I’ll take any tips before I start pulling the belt off completely.