Bobcadcam v28 Thread modeling

[Olokio]

I have searched all over and I can not find a thread for this so here it goes:

I am trying to form threads in a 3d model in Bobcadcam V28. I have a model, roughly a 2 5/8 id tube that I want to display 2 5/8-12 threads in for display purposes.

Specifics: thread major @ 2.535in, thread minor @ 2.625in, thread pitch @ 0.0833, thread depth @ 1.0in

What I have tried: I used the spiral command to wrap a spiral at the thread major inside my tube, then drew the geometry for the thread pitch minor - major with a 60 degree cut out and tried to sweep the angle along the spiral path. I get a rendering for the sweep but the angle seems to rotate around the spiral changing the orientation to the top where the triangle is backwards. I was going to try and boolean subtract this rendering from my tube model to cut out the threads but it is not right.

I hope this makes sense to someone and any help that could be shed on the issue would be appreciated I can try and upload pictures of what I am getting but I am looking to see if anyone else has successfully modeled threads in bobcadcam v28, how did you do it?

-Chris

 

[HuFlungDung]

I don't use Bobcad, but you can see if you can find the same sort of options as I have: I make a 4 edge surface consisting of wireframe that I construct. I create a helix at the major diameter and another at the minor diameter. These have to be positioned properly so that the minor helix is a half a pitch away from the major. Make the helices exactly 360 degrees long in rotation. Draw a line across the ends (do both ends), joining the helices. Then use 4 edge surface (chain pick order and direction is critical to success). You'll need to do this again to make the other face of the thread, with due regard for where you place the helices to get the shape right.

After you get these two surfaces constructed, they should look like a sharp V thread. If you want to get fancy you can add flats to the root and crest to really go authentic Copy these surfaces as many times as needed to make up your thread length.

The reason I only model a single turn is so that the surface doesn't distort trying to do several full turns as one complex model might.