Need Help Top of Y-drive belt is slowly being sanded down

[KeepPunkElite]

I've had issues with my old Mimaki jfx200-2513 and have been able to fix them thanks to online help. But now i have a new issue. Our old y-drvie belt was falling apart when i got hired but after a couple months, i noticed it was falling apoart much faster then before. The top of the belt was being ground down and exposing the wire inside. This caused y-motor and position errors that would stop our prints with no method of recovering the print. So I went ahead and got a new belt and placed it. It seemed to fix the issue for a couple days until I noticed the same wear and tear at the top edge of the belt and then got a position error during a print. So now I don't know what the hell the problem is. Can someone help a new guy?

I attached a video showing how the belt is going over the top of the y-drive cyclinder and causing the fraying.

 

[Smoke_Jaguar]

Bearings would likely be my guess, the idler and drive pulleys both use 2 bearings. If one is dragging a lot more than the other, it will cause the belt to 'walk' towards the edge of the pulley and wear out. The pulleys are available, but they are stupid expensive (hundreds of dollars each). As for bearings, good ones are under $80 for a set.

F699ZZ for the idler pulley.
629-2Z for the drive pulley

2 of each to rebuild idler and drive. We went high dollar and uses McMaster Carr, but they stock the good stuff. The bearings are press fit, but we used a big Allen key and placed them on a block of wood with a hole drilled out to tap the bearings out through. Worked a treat.

 

[KeepPunkElite]

OK found the issue, the tension on the belt was too strong and I had to give it a lot more slack before it started to center on the pulley. The old operator had the tension screws all the way. Now that I've loosened it, the issue seems to have resolved. If the sanding issue returns, I'll try replacing the bearings.

 

[Smoke_Jaguar]

Yup, that'd do it as well.