IGUS vs linear bearings

Purely for science I tested out some IGUS 8mm linear plane bearings. Here's a little video of the normal LM8UU's and IGUS ones to compare the noise they make.


Other interesting differences:

Cost: Fing expensive. I think these were about £8 each, for which you can get a dozen LM8UU bearings.
Size: Annoyingly they are exactly 1mm longer and 1mm wider than the LM8UU. Quite infuriating because I had to reprint my x carriage with wider gaps.
Performance: Very smooth, but x carriage is still quite noisy at certain speeds. This suggests the noise issues are caused by resonance in the structure, and sure enough, applying dampening on the parallel rails (i3) mitigates some of the noise. They are quieter generally though in most cases.

What about friction? The metal ones are louder because they roll (at least from what I understand), but they may have less friction because of it. It probably won't make a difference unless there is a big cantilever setup where the bearings have to take a lot of torque.

The sounds of resonance might be caused by slip-stick too. Using O rings or dampening washers on key parts of you printer can reduce the resonance a lot, but you have ot be careful not to make it too flexible.

Yes, I didn't have an objective way to measure the friction, but they are very slippery an it *seems* to be more slippery when you apply a twisting force to the bearing. In the video when I'm sliding the up and down, I'm actually pushing into the rod and twisting to try and make life difficult for them.