Interesting Modeling problem

[scott_lester]

I have run into a part that I am having trouble modeling and needed help from you guys; you have never let me down. I am trying to model the thread on a #2-8 x 3/16" stainless steel drive screw and i am stumped.  i cannot figure if I need to do a cut helix, some sort of sweep and then pattern or what.  Any short video of your solution would be great to teach me the best way to create these threads.  Currently I have just cosmetic thread and a call out, but I would like to see the real threads.

[12GAGE]

I have two thoughts

Start with ordered standard part

1.

Draw a star shape on the bottom of the head (start with a polygon or two as a guide)

Draw a helix line from the bottom of the head to where dim S starts

sweep the star along the helix

Then use round/radius to blend and/or perhaps a revolve cut

2.

The star shape/helix line could be simpler if the regular helix command can create the sweep rather than a helical line as a sweep path.

[Imics · Accepted solution]

Hi,

Here are two small examples (what are similar to @12GAGE's good solutions):

BR,

[SeanCresswell]

Hi there @scott_lester,

We use these in production at work, and I have a model of the type we use......if I recall correctly, I just modelled one helical flute, and patterned it about the shank.

I'll log onto our NAS server tomorrow when I'm back home, and check. [& append a copy of the model here]

[beachcomber]

I would never bother with the helix on something like this - the simpler the model the better.

It just adds unnecessary detail - I was once told to avoid using a helix as it is one the most complex forms of feature.

[scott_lester]

I agree, but this model is ONLY for the spec drawing; I have a simplified version for assemblies.

[scott_lester]

Thanks!  That helped a ton!  I got it.  I forgot about the twist function in the sweep command. As mentioned, you never let me down.

[12GAGE]

As usual, Imic's has identified the path of least resistance.