Creating threaded nuts and bolts
Hi there!
Did a quick section in Fusion and it seems to leave the appropriate tolerance. Are the measurements you're reporting taken from the printed part, or from the Fusion model?
Keep in mind that a 3D printer (depending on the type) does not have such perfect tolerance, and parts can come out a bit larger than expected. Especially with threads this can very quickly cause problems.
I would suggest trying Ansi 1/2-12 as it has a greater flank angle and overal more uniform fitting tolerance. Also aways pick the lowest fitting class.
If that still doesn't work, maybe you could pick 9/16 for the internal and 1/2 for the external threads. It will look way too loose in the models, but if you imagine both surfaces being slightly offset by 3D printing inaccuracies, it might just fit nicely:
Cheers,
Niels
Actually, scratch that! I just found you can press/pull the threadform surface. This will give you more control to fine tune the fit in printed form.
Perhaps instead of my example below, split the difference of the offset between the internal and external threads to keep the overall form the same.
You could make a test piece model with a few threaded holes and bolt, each using a slightly different offset (and marked in some way you can tell them apart later) to hone in on the perfect fit.
Hope that helps!
Niels
Here is a quick print with a #8-32 hole and a cylinder - threaded in Fusion. Printed with MakerBot Replicator 2X and tweakes with tap and die.
