would it be hard for me to add a multi-lead thread feature? about threadprofile HOT 10 OPEN

I think I have it fixed now. Latest version 1.83. Please update and test. In the future it is probably better to create a new issue so that you are able to close it when satisfied with the fix.

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I think I've found a way to add 2-start and 3-start threads in v1.75. Usage: make a standard v-thread profile and change the Variants property to 2-start or 3-start. The helix should automatically update its pitch to 3 * v-thread pitch for 3-start and 2* v-thread pitch for 2-start variants.

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I think you will need to sweep your profile the traditional way in order to make a multi-start thread, but I haven't given this too much thought. You could use the workbench as a starting point for creating the profile. Make a thread of appropriate radius and pitch with thread count = 1, and then use the part workbench cross section tool to make a cross section in the yz plane. Take the new cross section object to draft workbench and perform draft downgrade to separate it into multiple edges. Delete the edges you don't need, then upgrade the remainder to single wire object. Use draft to sketch tool to create a sketch from the wire and complete it in the sketcher to make something you can sweep along a helix of the appropriate pitch.

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I am rather late to the party, but for (external) multi-start threads, could you try the FCGear module? A worm gear is just a thread.

In its current configuration, you cannot put in the lead directly as it is written in terms of module, but there is an easy conversion: lead divided by pi is module. Pressure angle is half thread vee-angle.

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I don't think it's possible to do multi-start threads with the way the threads are made in this workbench.

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It seems like this only creates one set of threads for a 2-start thread (using v 1.82 on FreeCad 0.20)

Is the expected behavior that the user would need to add a second identical V-Thread with the 2-start variant, but with a 180 degree rotation?

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No, expected behavior is you get a 2-start thread

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Interesting.

There may be a bug in the generation of the second (and possibly third) thread starts. Should I file a separate GitHub issue for this, or continue on this thread?

I'm seeing correct doubling of the helix's pitch, but no second thread start

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I found the issue.

If an offset is applied on the Z axis to the VThreadProfile object (in my case, 1mm), then the second-half of the 2-start thread is never generated in the profile:

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@mwganson Thanks - Normally I would have created a new issue - I just wasn't sure, since this issue looks to be the one that originally adds the multi-lead threads #25 (comment) and it's still open.

It looks like 1.83 fixes the issue I was seeing with a z-axis position offset of 1mm causes the second lead profile to not be rendered. Thanks for the quick resolution and your awesome work on this module!

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