Problem with constructing a thread (for 3D-printing)

hansrudolf

Hi all,
again one of my strange problems. I want to draw a thread in a nut, which I want then to print on my 3D-printer.
I managed to draw the nut, the helix and a plane perpendicular to the helix. Furthermore, I could also draw a triangle on that plane. But when I want to sweep it, I see it only in dashed lines (also if I use the section view) and the sweep does not work.
The strangest thing is that many months ago I could do that operation, with the difference that I used a circle instead of a triangle.

https://cad.onshape.com/documents/221a69568cae352864f9ca25/w/cde28ce27d88e56548e72d0e/e/54fbaad6bbd23af4244eab78

(hope that works)

Regards,
Hansrudolf

_anton

There's a custom feature for modeling threads: https://forum.onshape.com/discussion/comment/84303

Do you actually want to model such fine features, though? You could either buy the nut, or leave just a hole and let the bolt make its own threads.

hansrudolf

Hi _anton,
I'm sure your answer was well-intentioned, but doesn't help me much.
I really want to know why my approach has failed, and working with that custom feature is way above my pay level. I tried to add that to my part, but found no way, especially as I didn't find out what's the real name of that function. "Search or paste URL" needs a meaningful input, am I right?

Anyway, thanks
Hansrudolf

robert_scott_jr_

I don't understand why the sweep didn't succeed since the sweep pitch and the sweep profile height match. However, decreasing the profile height to 1.4mm works. Seems the error message might have been more in the line of 'self intersecting'. - Scotty

https://cad.onshape.com/documents/4d8a1ca8337e0cf764688ac6/w/c37405a9c9af56dca9503b66/e/0c4f1b9bebc864a534145ffa

_anton

I think the immediate problem is that the swept body is nonmanifold (and, if you increase the sweep profile, it'll be self-intersecting). So yeah, decrease the dimension a bit.

hansrudolf

Many thanks again for your help.
I could now draw a part with an external thread, and print the nut part also. The nut is not perfect, the thread does not 'fade out' correctly at the end. Don't know how I could that describe better, the thread should continue about 90 deg. more (a guess could be 180 deg.)
Another internal thread failed again. I think I will use a thread tap for this one.
Maybe I find some time to study how that custom feature works.
Case closed for the moment.
Kind regards,
Hansrudolf