Linear bearings and rods
I’m seeing some serious slop in my printer’s bearings, which seem to have scored the rods pretty badly over time. They’re Chinese LM12UUs on stainless steel rod (which was absolutely not made for linear applications). They have always been well-greased, but with the bearing’s balls always running over the same spot, it seems that the rod was simply too soft and gave in. For my next printer, the #Cerbris , i have ordered chrome plated h6 HRC58 linear rods, which should be a near-ideal match for LM-type bearings.
What rods and bearings are you using and how are they holding up?
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I don’t know for 3D printers, but copy machines generally use nylon bushings on the scanner head because the nylon has just the right amount of give to not stick (with silicon grease) and is soft enough to not damage the rods.
Drill rod with lm12uus they are scored like yours after about 5 months of use. I’m moving to igus polymer bearings next. I used them in a CNC router build and they worked great.
@Will_Dent Thomson is just a brand for HRC60 unplated carbon or stainless steel, right? If so, there’s no reason why it shouldn’t work. @Joe_Spanier how are the igus holding up under the load of a router? @Wayne_Friedt that sounds pretty wild - got a link?
When I first built my machine it was at the end of the radial bearings on drill rod dark ages. It didn’t take long for those rods to show some wear. I then used some LM8UU bearings on the drill rod which did not last long at all after that.
I have only ever known it by its trade name, It’s designed for linear movement and case hardened. They usually use it in injection molds and heavy duty applications. So yes It does sound like we are talking about the same stuff.
I’m going with the idea that I can replace low-cost bearings and drill rod a couple of times for the cost of the top-quality stuff. Then again, my printer doesn’t even run every day.
I went with what @Tim_Rastall spec’d out for the Ingentis. Rods are nearly fucking indestructable. I wasn’t even able to score/mark the chroming on the outside of them with set screws. That, paired with self aligning bushings. I’m a big big fan of the bushings now, they’re so quiet.
