Prusa MK3 x/y adapter kit for igus RJ4JP bearings by loskexos

Last crawled date: 3 years, 1 month ago

Adapter set to switch from LM8UU linear bearings to IGUS RJ4JP-01-08.
target:
make replacement possible without redesigning carriages etc.
x/y axis only, z axis is not making a lot of noise and wear
avoid deformation on installation
keep x/y axis geometry (endstop etc)
X carriage:
3 washers on x Axis needed to eliminate play (2 top rail, 1 bottom rail) to eliminate x-axis play.
2 shims for x carriage needed (at my copy of carriage parts) - to avoid deforming the igus bearings and slightly increase resistance.
Y carriage:
Casing to spread the force for firm mount and for fixating y position in bed carriage holes.
Keep ability to careful adjust mount force via screws.
3 pieces needed for top and bottom part. Print without brim/support.
Additionally needed: 6x M3x10 screw, 6x M3nS square nut
Print in PETG due to proximity to heated bed.
Mount the bottom part with the indented side towards the frame (for the rod that holds 2, for the other one orientation does not matter).
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this is a work in progress, I'm still assembling my mk3 ;)
update 29aug18: added shims for x carriage
update 15sep18: prints come out nice so far. No further modifications needed at the moment. On a paver in LACK enclosure it is really quiet.
update 13apr20: Happily printing for ~1.5 years now. Kept the IGUS bearings when converting to mk3s last year.
Printing covid headbands at full speed I started to wonder what difference the linear bearings would make. Had a set of Misumi bearings and Rods sitting in the drawer since a year and now finally got curious enough and had the time to swap.
Result: accuracy is definitely better. Ball bearings a definitely more audible. A LOT. With IGUS bearings I could join phone conferences in the same room. With the ball bearings I get irritated watching TV sitting 2 rooms away... (no they are not broken and are well lubricated with lithium grease ;) ).
Like one comment said - these IGUS bearings are meant to be used with some compression. I'd say accuracy can be improved with more sophisticated mounting mechanism. Too much (and especially punctual) compression is impacting friction heavily. I'll put the printer in the basement during summer. Probably will go for IGUS again next winter...
Add1: mk3s x carriage: no washers for the lower bearing. For between the upper ones optional and only with diameter smaller than the beariengs.
Add2: mk3s x carriage: added stl for a set of shims for mk3s with 4 different thickness to experiment (thickest worked best for me).
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