I am having problems sweeping the triangle to create a screw, I've merged the triangle

zhikun_li

bruce_williams

@zhikun_li

Please share your document.  See guidelines here.

https://forum.onshape.com/discussion/9107/forum-post-checklist-read-this-first#latest

bradley_sauln

The way you have your triangle set up, the sweep cut will result in zero thickness geometry OR the triangle profile is not 'piercing' the helix path. Please take a look at this: https://www.onshape.com/cad-blog/tech-tip-creating-a-thread

NeilCooke

Geometry will self-intersect which is a no-no

michael3424

This image gives some info on the critical dimensions for UN/UNF screw thread forms.  Note that there are flats knocked off the V-shape.  I normally incorporate those dimensions into the thread form when I have to accurately model a thread.  If you are 3D printing you might want to make simple test threads to see if the dimensions need to be adjusted for filament shrinkage during the print process.

michael3424

Sorry - forgot to paste in the image:



P, here, stands for pitch or tpi.

MBartlett21

@michael3424
What you can do is extend the external edge of your triangle a bit (it doesn't matter how much)
The sweep should then work

joshua_smith082

on a helix, if your sweep body dimension is the same as your pitch then the sweep intersects. Shrink your sketch just enough to not intersect (.01?) and it should work.