MR128 Bearing 8x12x3.5mm

This is a simple two-part bearing sized to match an MR128 bearing, that prints in less than 6 minutes.
ID: 8mm

OD: 12mm
Thickness: 3.5mm

To assemble, flex the INNER “C” race into the OUTER ring. Once you place a shaft through the inner ring, it cannot come out. For faster rotation, you can add a small touch of light oil or silicone/PTFE spray. For slower rotation use grease to lubricate it.

Note that this design works well for low speed rotational motion, but is not really suitable for thrust or torsional loads. To put it another way, this design works well if the shaft is supported by two bearings spaced a reasonable distance apart, and the shaft does not get pushed on either end too hard.

The print profile is 0.12mm layer height, and I have adjusted the speed and seam settings to ensure the parts fit together well. You may need to use a scalpel knife to trim away any small elephant foot from the parts to ensure they run smoothly together.

I have adjusted the model dimensions so that the final printed size is correct. I printed mine on a Bambu A1 using cheap Kingroon PETG, so your results may vary, which is why I have also attached the STEP files if you want to adjust the size.

I created it specifically for the Card Shuffler by Josh-3D because 1) I didn't want to purchase and then wait for the bearings and 2) because I don't think it's necessary to have proper metal bearings in there. I found it works very well but had to modify the handle to reduce torsional movement.