unterhausen

fusion is free for hobbyists. I think you have to get a new license every year. It had been the full version, but too many companies were cheating, so they are limiting it in ways that probably don't matter. The full version is free for startups under $100k, but requires an interview.

https://productdesignonline.com/tips...pcKZsX_DWDPndM

GiovanniLiCalsi

You can CAD design lugs, then have the lost wax investment models made, slightly larger, to allow for cast metal shrinkage. The model can be printed in plastic or a hard machining wax.
The best metal for lugs are 304 stainless steel. The lugs will need to be cast in a vacuum induction casting machine, at high temperature. Using stainless steel lugs is much better than chrome plated lugs, because the plating process causes hydrogen to seep deeply inside the steel. SS can be polished to a high luster and will not corrode.




Here is a Columbine frame with SS lugs.

unterhausen

Are you speaking from experience? Those Columbine bikes are amazing, but it's all hand cut from lugs that anyone could have gotten at the time

GiovanniLiCalsi

Yes, from experience. I do lost wax investment casting. I, also, know the owner of Columbine Cycle Works. Those Columbine stainless steel frame lugs were lost wax investment cast.

Doug Fattic 

While it is always dangerous for me to be absolutely certain of anything, I believe Columbine carved his design from standard stainless Henry James lugs. At some bike show years ago Hank and Monica invited me to eat with them and John after the show and we discussed how he used their lugs to make his frames. I am not positive of what exact methods he used but it looks like to me he made thin cuts into the lug with a jeweler's saw and then bent the slivers away to make the curly cues.

unterhausen

It makes sense that some of the ornamentation on a Columbine is investment cast though, it's just a tremendous amount of work otherwise.