I am curious how often do you service the linear rails on the 3D-printer:
- How often do you lubricate them (MGN9 or MGN12)?
- How do you lubricate them?
- What volume of lube do you use?
Explanation of how often you should do it (HIWIN Lubricating instructions for linear guideways and ballscrews)
Most 3D-printer use MGN12. Reading the HIWIN documentation they shall be lubricated every 20-50km (depends on a lot of factors).
How much is 50km in print time? Assuming an average speed of 300mm/s that would be approx. 46 hours!
In other words, the generic MGN12H carriage needs 1-2 times per week maintenance.
How much lube is suggested (horizontal mounting)? 70µL for MGN12H. For MGN9H it is 30µL!
It’s not so much about lubrication as it is about trying to prevent seal wear. When the wiper seal gets worn and can no longer keep the dust and grit out, the rolling elements have little time left.
If the bearing as lubricated correctly at installation time, it should never need re-lubrication. But it’s important to keep the rail surfaces clean. And it’s amazing just how dusty those rails can get and just how abrasive that dust is on the bearings.
I don’t lube the rails, it attracts too much dust. But I do wiper the rails periodically. I replaced the linear rod bearings and rods on my old and trusty Mk3s+ after almost 3500 hours of operation this last winter. Though I should have probably done it a bit sooner.
I’ve never had and issue with the linear rails rusting in all the years I’ve been 3D printing. But I do live in a drier temperate climate also. But dust will eat the seals up very quickly as well. If rust is a worrisome issue, hard chromed linear rods are also easily available to prevent any worry about rust. And they would outlast the the non-chrome rails significantly. That’s what I use.
As always YMMV