Creating Threads

Is there good way to create to threads? I have tried helix/sweep but that does not work well.

Hello- Helix and Sweep1 (Roadlike, Top for a vertical thread axis) RailRevolve is what I use as well.


That’s what I was trying but I am not getting the edges to match up. Any trick to that?

I have the ends of the profile intersecting the helix.

Hello- make one revolution and then stack it up to get the full length of threads. It will mesh more cleanly that way as well.


I might be making progress, but I with each new level, I always get a bad surface that i have to extract and recreate.

Sounds wrong… post your curves and surfaces…


I discovered a bit of weirdness. Here I have three segments. The center is the original. The outer ones are copies. If I try to join center/left it works fine apparently. If I try to join center/right I get a bad surface.
Problem (687.5 KB)

Hello- here’s how I’d set this up-

thread_maybe.3dm (833.5 KB)



I get the same problem with your file. If I copy to the left (view in image) I get a bad surface when I join. When I copy to the right, it joins fine.

But when I try to do a second copy and join, I always get a bad surface. I have to extract the bad surface (which fortunately always has a straight profile) and loft to file the hole.

fwiw, I never make threads anymore- I use Mcmastercarr and download parts from their site-

so much easier, faster, and higher quality than making your own.

Thanks, that will likely help in the future as there are things to do with NC threads.

My immediate problem is that I am working on adaptor plugs for battleship armor that do not use a standard thread or diameter and have not been made since the 1930’s.

ah… carry on with Pascal’s advice then…