V-wheel indentation

Just noticed my v-wheels are digging into the v on the extruded rails (the indentation is on the outer side of the v not the inner). It’s only bad on one side, dug in enough where I can feel it with my nail. Strange thing is it’s only happening around the center of the machine.

Any ideas what could cause this? Are the wheels just too tight or the machine isn’t square, or?


X-axis or Y-axis?

Post photos of the matching V wheels?

Is there a correct number of washers on the V wheels and is their placement consistent?

Its the right y-axis.

I think they have the washers and the placement looks ok, but I’m not certain. I’ve never installed any, my machine was purchased used so it’s possible there was incorrect installation by the previous owner.

Photos attached

Seems to me that you may need to replace the V-wheels. You can order those from the Carbide3D shop. They do wear out over time with use. Pretty sure the outside circumference of the V-wheels should not be applying force at the base of the matching aluminum extrusion - all the forces should be on the sides of the V to keep the gantry aligned.

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It looks to me like this is cosmetic, but if you wish, you could get a Maintenance Kit and rebuild your machine to pretty much like new:

(just be sure to pick the SO3 version)

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Yea it seems a bit strange, not sure why it’s happening or if it’s a recent or old problem. It’s only happening in a 1.5’ section around the center of the rail on that one side so I thought that might be indicative of something. On the other side it has the same line but it didn’t actually dig into the aluminum, just made a visual line that I can’t clean off.

I do have a full maintenance kit on hand. Although I want to learn how to disassemble and rebuild certain parts of the machine I’ll probably hold off until something is confirmed off or broken.

I am surprised the v wheel could do that. I would expect the rail to deform the wheel not the other way around. I had a similar situation on a “purchased used” S03 X- rail, but it was the idler pulley running too close to the aluminum V (metal on metal), cutting into its side. I ran it for a long time before even noticing. I dont think it had any impact on performance (cosmetic like Will says) but I fixed my situation with a thin washer to give more clearance. I quickly realized when you buy one of these used, who knows what mess the previous owner left. If the V wheels adjust correct and the Z axis is firm with no back-forth play it could definitely be old wear and not an active concern. Look it over close. Cheers.



I’ve got those marks on my X rail too, it was the washers on the belt idler bearings grinding away at the extrusion, carefully pushing those washers up whilst re-tightening the bolts on those belt idler bearings sorted it for me.

As it’s only happening in the middle of the rail, I might also wonder if the V wheels are properly tensioned or if the Z axis is a little loose.


Appreciate the info fellas. I checked over all my eccentric nuts and the bottom right one on the HDZ was loose (same side as the issue) so I tightened it up. I’ll have a look at the idler bearings first thing tomorrow.

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