Counterfeit igus bushings?
On the left are bushings we purchased from lulzbot last year, on the right was sourced online.
The bushing on the left has little play, and outer diameter is 22mm. On the right has about 0.5mm play, and has 22.6mm outer diameter.
Note that the ones on the left are stamped on the side.
Update: they are 2 different parts, on the left is rjmp, on the right is rjm. Our vendor shipped us the wrong parts.
I tried to press-fit the one on the right into the 3d printed holder, which cracked the holder quite badly.
Igus specs these bearings as +2% the inner diameter which at 12mm shouldn’t be more than 0.24mm
Originally this type of bearing is purposely oversize to be press fit into a machined bore. Once press fit then they tighten up and the play is removed. Then igus brought out a drop in replacement for the lm8uu bearings which are not pressfit. Maybe you are seeing both types here. With the counterfeit one a copy of the press fit version?
This kind is press-fit, but the one on the right is out of spec. Per their site it should be 2% tolerance:
http://www.igus.com/product/4
So update, I noticed that there is another part, rjm-01-12, which is lower tolerance version to the one on the left, which is rjmp-01-12
http://www.igus.com/wpck/16403/DryLin__R__RJMP
Vs
http://www.igus.com/wpck/3665/drylin_r_rjm_01
It appears that you are correct, the one on the left is likely the rjmp model, on the right is rjm. So our vendor shipped us the wrong ones…
