Please click here and download the Test Fit model: Test Fit.3mf
Print "Test Fit.3mf" with normal settings at 0.2 or 0.3mm layer height. These parts have small tolerances between them and there are 2 sized rings. First place the widerring all the way onto the axle. It should not move or rotate on its own, It should stay in place with a tight friction fit.
Then take the narrower ring and also place it on the axle. The narrower ring should be able to move/rotate freely, but still be snugly on the axle. This narrow test ring represents the wheel later on, so it should turn freely. To make them fit, you can also lightly sand if there are any imperfections from 3d printing on the axle.



You may need to calibrate your 3D printer’s extrusion multiplier to get the correct fit. If you are having trouble getting a correct fit, consider using “horizontal size compensation”. This setting controls how many millimeters the features printed will be enlarged or shrunk by. If the fit is too tight, try -0.1mm compensation, if it's still too tight, try -0.2mm, etc.
- In PrusaSlicer this can be found under Print settings -> Advanced -> XY Size Compensation.
- In Simplify3D open your Process settings, click “Show advanced” to show all the settings, click the tab labeled “Other” and then find Horizontal Size Compensation.
- In Cura the setting is called "Horizontal Expansion"
If it is relatively close, then you can also probably get away with leaving your printer settings as they are, but then you will have to sand more.