My machine has been working excellent, but lately the movement of the gantry seems to be getting quite rough. If you watch the top of the Z axis you can watch it shaking as the machine moves from point to point, even when it is just traveling. The rough movement has started transferring into my cuts and it is quite noticeable as I have been cutting a lot of HDPE, which has a shiny finish after cutting.
It seems as though the bearings are smashing bits of sawdust and/or HDPE into the rails and the surfaces of the bearings, causing the rough movement. I have tried running a razor-blade over the bearings that I can access while it is traveling to remove the debris and it seems to help. I am also wiping off any debris from the rails fairly often. I have just today started using a dust collector attachment on my spindle in the hopes that it will keep some of the dust off of the rails, but it does not catch everything…
I don’t have the degree of the problem that you describe (yet), but I have noticed a lot of dust on the bearings and conduit, and cleaning it is a bit of a hassle. One thought that I came up was to add little brushes that would clear the dust as the machine moved around. If I placed them at an angle, then it might work better by pushing the bits perpendicular to the direction of travel. Not sure if it would work, and to do it right would require A LOT of locations.
I would love to see how others have addressed this.
Interesting. What I think is going on here is you need a bit more tension on the bearings. Typically the high point load of the bearings might let stuff build up on the edges of the bearings but nothing can handle the actual contact strip. Other option is to shield it from dust a bit or get in with the vacuum during cuts a little more often.
Has anyone tried putting brushes in front of the trucks? I think a little sawdust on the rails is not a big deal in the end, but I wanted to play around with aluminum cutting and it would maybe help my sanity is the rails were clean.
I have experimented with brushes in front of the rollers but the dust still builds up. So it was just another part to maintain and clean - as Ryan proposed try to set your tension right and there won’t be any built up dust where the surface touches the bearing.
There are also two types of bearings, some are covered in sticky oil on the outer surface when they are delivered. These will especially attract dust that sticks to the bearing very well. Since I knew this from my first build, I used “non-oiled” bearings for the second MPCNC and havent’t had that much biult up dust anymore.