How do I get my pierce and sweep to work when threading?

gabriel_francis261

I am trying to thread a part with a thread of M14*1.5. I have entered 1.5 as the thread pitch to make the helix and it seems right but I am having trouble in making the triangle to sweep along its path. I have tried searching the problem and haven't really made any progress. I tried a larger triangle with a construction line but I can't get the pierce to work. This may be what is stopping the sweep from working.

Eric_Gauthier

Looks like your sketch of the triangle is parallel to your path starting point when it should be perpendicular or normal to.

John_P_Desilets

@gabriel_francis261

I don't always recommend putting a thread on a part because of how expensive it can be for regeneration times. However,  if the part is 3D printed or plays a critical role for how parts fit together a thread feature is needed. 

There is a custom feature for creating threads that you can add to your toolbar. This is a great feature and has several standard thread sizes.

https://cad.onshape.com/documents/6b640a407d78066bd5e41c7a/w/4693805578a72f40ebfb4ea3/e/f8aea9e5c33e02eab0854a4f#_ga=2.232152220.2018415010.1590505462-1556897280.1583850809

I made an example of how I like to model threads if you don't want to use the custom feature.  Here is a link. 

https://cad.onshape.com/documents/bdfddb378ebfbb4843a92e38/w/4c86b4c902f5126fec13dd53/e/650b3e9aef9fb16aa804fb07

In this example, I used a construction surface to place the helix on. This is so the thread can start before the solid part, the same way a thread would be cut on a lathe. 



Next I added in the chamfers and undercut.



Modeled the thread profile. 



Sweep remove. 



Let us know how you made out. Good Luck!

Eric_Gauthier

Looks like your sketch of the triangle is parallel to your path starting point when it should be perpendicular or normal to.

John_P_Desilets

@gabriel_francis261

I don't always recommend putting a thread on a part because of how expensive it can be for regeneration times. However,  if the part is 3D printed or plays a critical role for how parts fit together a thread feature is needed. 

There is a custom feature for creating threads that you can add to your toolbar. This is a great feature and has several standard thread sizes.

https://cad.onshape.com/documents/6b640a407d78066bd5e41c7a/w/4693805578a72f40ebfb4ea3/e/f8aea9e5c33e02eab0854a4f#_ga=2.232152220.2018415010.1590505462-1556897280.1583850809

I made an example of how I like to model threads if you don't want to use the custom feature.  Here is a link. 

https://cad.onshape.com/documents/bdfddb378ebfbb4843a92e38/w/4c86b4c902f5126fec13dd53/e/650b3e9aef9fb16aa804fb07

In this example, I used a construction surface to place the helix on. This is so the thread can start before the solid part, the same way a thread would be cut on a lathe. 



Next I added in the chamfers and undercut.



Modeled the thread profile. 



Sweep remove. 



Let us know how you made out. Good Luck!

gabriel_francis261

I changed the plane that I put the sketch for the sweep on and it worked! When I changed the plane the pierce and then the sweep were able to work.
Thanks Eric and John!
You can view it with this link if you would like:
https://cad.onshape.com/documents/86f0080d71400dd6f6e3ee3b/w/b606a46a0f0b00acc3383e62/e/0398403b7959aaf12de0d2fc 

daniel_irwin183

Yeah I'm still struggling - the thread profile does not seem to want to attach itself to my helix - though, strangely I tried 'coincidenting' it and that appeared to work (but obviously, as a coincident will not work for this as it is merely a projection of my plane.