Y-Axis Belt Just Snapped


I’m not sure what caused this, but the right y-axis belt (6mm) on my Late 2015 Shapeoko 3 just stretched past it’s limit and snapped. Yesterday, after tramming an 11x11 inch plate of aluminum down 1.5 mm I noticed that the right belt had substantially more slack than the left. Upon inspecting it, I found one of the teeth to be stretched to the point where it was almost flat.

Fast forward 18 hours… I somewhat forgot about the flattened tooth in the belt and just simply re-tensioned the belt. I ran a job of cutting a part out of acetal, and 90% through the job I see some jittering as the gantry traversed back in the y axis. That’s when I noticed that the belt had completely torn.

I can only think that the issue is that I may have overtightened the v-wheels on that side (I retightened everything recently after upgrading to the threaded table and updated z-axis plate).

Any thoughts? I would really hate for it to happen again.

Every so often this happens — the belts have to be considered consumables — Brandon (Improbable Construct on the Shapeoko forums) had a belt go after over a hard year of milling.

I think the U.S. made belts from SDP/SI have better quality control, and they seem to have “grippier” rubber which helps w/ not skipping a pulley tooth — but maybe that’s just my patriotism showing through.

List of sources and specs at: http://www.shapeoko.com/wiki/index.php/Parts#X-_and_Y-Axes and specifics at: http://www.shapeoko.com/wiki/index.php/Belts_and_Pulleys#9mm_wide_belts_for_SO3_X-_and_Y-axes

Thanks for that info William. I’ve only used my machine for no more than 30 parts since I first received it, so the single belt stretch after relatively so little use was surprising. I’m going to place an order for the upgraded 9mm belts and pulleys. I’ll be sure to pay close attention to my tensioning of everything.

Thanks again!

Shoot us an email to support@carbide3d.com and we’ll get it taken care of.

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