Problem with belt tension/slippage/noise

I am an amatuer at roasting, and I am no expert on using the Bullet. I deep cleaned the machine recently, and tried roasting today. The motor belt appears to be slipping (rat-a-tat noise, drum stops). I took off the back cover. The 3 mm nut holding the motor in place is tight, but the motor housing drifts toward the left when I spin the drum (and makes the rat-a-tat noise), even though the nut is tight. Is there supposed to be movement? The spring pushing the motor to the right is seeminlgy OK. I assume there is supposed to be some movement of the motor housing, otherwise what sould be the purpose of the spring? The screw on motor shaft is tight. Anyway, I’m unsure how tho proceed. Any ideas?

Best start with the Bullet manual. IIRC it has instructions on adjusting the drive belt.

Also the Aillio site has Support info.


Thanks for your response. I did read the manual, which is how i knew to check the motor hpusing bracket. My question is regarding the top screw on the bracket. Even when the screw is toghtened as much as possible the bracket can still can move to the left fairly easily. Is it supposed to be like that? Or do i need an extra washer so as to allow the screw to be tightened to eliminate any sliding to the left?

I have a V1.5 Bullet. One of the things that changed is drum motor tensioning. I’m not familiar with what to expect with a V2 version. I believe I recall that there is some free play but that’s a WAG on my part.

I recall some videos on the Aillio/Support pages but didn’t spot them immediately when I got that link earlier. At least one of them related to drum motor adjustments. When I looked thru those videos a couple years ago I think I recall a link to In fact as I went to find a link to Aillio on Vimeo I stumbled on this one related to drum motor tensioning. Maybe this has what you need.


Hi @chestdoc51,

Have you taken off the Drum during deep cleaning? This might be an alignment issue. We suggest sending us a ticket ([email protected]) as you might need to share some pictures and that can be too sensitive on a forum.

For the record, All V2 Bullets have a Tension Spring to maintain the Belt tension. With the Tension Spring present, you don’t have to secure the Screw on top of the Drum Motor. Also, the Belt would slip if the Drum is spinning too fast (with hand). You should feel the Drum spinning slowly and smoothly with a little resistance when you spin the Drum by hand clockwise. If the Drum feels completely stuck, then it’s most likely an alignment issue.

Best regards,

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