Found a thumping when my machine is cutting or scoring!

#1

I was trying to make a craps table layout to practice again and while cutting it out a notice a loud thumping while the machine is making moves to new start points. watched it for a bit and noticed that it was from the belts jumping across the teeth of the g2t pulleys. I have a new assembly for the head that has a belt but I am in need of 2 for the main gantry. I would like to find some from somewhere like gates so I was hoping to know the length if those 2 closed loop belts. otherwise I was hoping to just get 2 replacements for these as I fear they are stretched.

#2

I’m not sure about the gantry belts but the carriage belt is a strip, not closed loop. I think the gantry belts are the same.

The ends are clamped under an aluminum block that has grooves that match the belt teeth. The first time I removed the carriage I disconnected the belt.
I was glad to see the dust on the belt marked exactly where it had been clamped so I could reassemble the belt to the same length under the clamp.

It seems odd the belts would have stretched, they are very strong and fiber reenforced. I have a lot of time on this machine and there is not a hint of stretching. Maybe the belt clamp is loose and the belt slipped.

Another possibility is that the belt pulley slipped, they are adjustable. You can see they are mounted in an adjustable slot on the rail. The tool to tighten/loosen them is a 3mm Allen.

I would wait to hear from support for an official answer,
but it seems to me more likely a pulley or a clamp has slipped.

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