My Prusa i3 Mk3 printer’s LM8UU bearings were acting up. It could’ve been an issue with the installation. Or they might’ve just been junk out of the box.
Regardless, it’s time to replace them. With three Igus Drylin bushings in-hand I’ve decided to swap those in on the printer, at least temporarily.
Check out the video above. I walk through the process of removing the old bearings and replacing them with the new Igus Drylins. There are also instructions on tightening the Prusa i3 Mk3 heatbed in there.
If you’re not familiar with the Igus Drylin they’re a solid bushing made of iglide J4. And it has lubricant built in the keep everything moving while it ever so slightly wears in. I assume that’s PTFE or an analog but it’s all trademarked product names rather than the types of plastic used.
The model of Igus Drylin busing I’m using is the RJ4JP-01-08 (specifications here). They’re about 12$ for 8 making them a fairly inexpensive alternative to a decent quality LM8UU bearing.
After a week of using the Igus Drylin bushings on the Prusa i3 Mk3 I’m happy with their performance. And they’re still as dead silent as in the video. There’ll be a follow up video and a example print once the bed camera’s up and running.
I’m going to create a proper housing for the IGus bushing. I just need to figure out the easiest to use material stiff enough to exert the proper clamping force on the bushing without breaking.
In the meantime rcaslis on Thingiverse has come out with a fitting to keep the bushings in place on your rods. https://www.thingiverse.com/thing:2835381
Although if you’re not tightening them down hard enough for that already you’re probably not tightening them down enough. They do require quite a bit of clamping force around them to compress and seat.
This should, though, help spread the force out over the entire bearing which’ll certainly make them work better.
Oh, and Igus also makes a linear adapter with a removable sleeve which may be better suited if you don’t want to make a housing. That’s the RJZM-01-08 and the JUM-01 (possibly with extra numbers for ID) replaceable liner.
Inhibit, did you ever complete that object? Also, what about https://www.thingiverse.com/thing:3009203 ? IDK the dimensions of the Igus vs the Drylin, so not sure if that will fit, but would that be an improvement?
I haven’t yet. Ended up getting a Lathe so I’ve been waffling between doing a 3D design and testing out some carbon-fiber impregnated plastic (PC or ABS) or just doing it in metal.
That and it turns out the PC is a bear for me to tune in on the Prusa. Although it was a bit easier in one of the smaller offset extruder printers.
Since the printer’s once again sounding fairly sandy I’ll probably get it done sometime soon either way. I’ll likely make a new design up since I usually avoid simple designs with overly restrictive licenses.
And yeesh. PLA bushings with a metal shell.. that’s just weird. I get the PLA bushings verbatim.. print them to size so they’re a direct replacement and they’re immediately producible if not that durable. But that seems like a lot of work to not just use a 30 cent sintered bronze bushing.