This is a simple press fit pillow block for the commonly used 608 (skateboard size) ball bearings. Ther are three versions that allow for three different mounting bolt sizes. These are M3, M4 and 0.25, they all have a hole spacing of 60mm. The bearings go in one way due to the lip on the face down side (as oriented when importing the STL into Cura) The M4 and 0.25 versions can fit two 608 bearings each. Print with a minimum of 3 walls and 20% infill, increase wall thickness for increased strength. Print the blocks laying down with the inner lip on the bottom side of the print bed , no supports needed but a brim is recommended. Message me for custom bearing or mounting hole requests.