The crank-in-a-box that I’m working on needs an axle stub to locate it in the box. I designed the parts that I needed in Fusion 360 and printed them out.
The first version is on the left below. As a by-product of the printing process you can see that the top, and to a lesser degree, the bottom of the part are slightly flaired out. As a result the parts won’t fit in the matching hole without being filed down.
The part on the right is my attempt to get round the problem.
I’ve gone into Fusion 360 and added a 0.5m chamfer to the top and bottom edge.
It works a treat and the parts now fit together very nicely. (Just to mention, I’m making the hole 0.25mm larger than the part resulting in a nice tight fit)