About this 3D model
This is intended to mount bearings like: https://sdp-si.com/eStore/PartDetail.asp?Opener=Cart&PartID=9908&GroupID=469&Qty=10 There is an upright version with rounded ends - a little tough to print, but doable. There are two versions on their sides, one with square ends, one with rounded - these are easier to print. The two most recent versions have the bearing hole oversized by .6mm - these should require very little sanding to fit the SDP bearings after printing.