Any advice on my nut & bolt? (not important, just practice)

[Tapap]

Good morning all.

Turns out there's a massive wait on on my next cad class. The first two classes focused on 2d and constraints, the third is when we were going to get into 3d design and the waiting list is 3 semesters out. I've been tinkering here and there with designs I can 3d print but now I want to focus on topics so I don't forget the skill I learned in class. This week I'm focusing on thread design.

For printability I made the nut hole slightly larger than the nut shaft but my threads are the same size and pitch.

 

[albie0803]

Not that it really matters but you may get a better shaped bolt if you cut the thread rather than add it. You can start with a nicely chamfered end and cut into it.
Also, bolt threads are normally under the nominal size rather than the nut being over.

 

[Tapap]

Not that it really matters but you may get a better shaped bolt if you cut the thread rather than add it. You can start with a nicely chamfered end and cut into it.
Also, bolt threads are normally under the nominal size rather than the nut being over.

That makes sense about the sizing, wasn't sure what I was thinking.

I don't think I follow you about the thread though. So if I cut it, what do I do to make the nut?

 

[albie0803]

Your nut is perfectly fine.
Use the same concept as the nut but cut the OD rather than the ID

Rather than starting with the root diameter and adding the thread to it, start with the OD size and use helical cut rather than helical boss.

With your bolt you had to trim the end and would want to chamfer it as well. 2 additional operations. By starting with the full size shank, you can either draw it with a chamfer or easily add one before cutting the thread.

In the real world a thread isn't wound onto a smaller rod, it is cut (or rolled) into a full size rod.

 

[Tapap]

Oh I see now. Thanks so much for taking the time to explain that.