Something like this I'm thinking.

Another slight revision of frame lines.  Rough fit of downtube.  There will be one more bolt through engine plates.

Sexy curvy lines like a womans hips.  

Thanks again for the comments, help and encouragement.

Tonites progress on fitting of the downtube to the engine cradle.  Welded in the flats that make the transition from the larger tube, just about ready to start tacking it together.

Ruttly wrote on 11/02/17 at 05:32:22:


Yes.  I don't have a complete plan yet but I'm thinking I will re-use or re-create the stock mechanisms and attach them using the same long bolts that go through the engine on the stock bike.  I may have to have another through bolt from plate to plate in the roughly the same location as third bolt on the kickstand side.

Seat tube partially fitted.

Cut and shaped rear axle plates.  I decided to keep them the same shape even though I only need the elongated one on the brake stay.

Ruttly wrote on 11/06/17 at 20:31:31:


Thanks.

How?  I've always loved to build things and I'm just dumb enough to see something and think hey, I could do that.  I like the challenge of creating things with simple tools and techniques.  

I started metal working in earnest about 6-7 years ago, I'd always liked it as a kid and finally had the time to spend more time on that kind of thing.  But I've always like to build things.  I think the hardest part of any craft is learning the patience to do each step well and not rush to part where you get the finished product.  I've learned that one the hard way too many times.  So I came to metalworking with some of that patience, most of the time anyways.

Those plates in the last picture were shaped with cut off wheel, depressed center grinding wheel and a stationary belt sander.  Duplicate shapes were created by stacking and shaping as one.  So nothing fancy, just some simple tools.  Lucky for me I have access to mill at work, the slots were done after hours there.  

As for the fixturing I start by imagining what I want it to do, how many directions of adjustments and and how many degrees of freedom will be loose at one time.  Then go to my scrap pile and see what I have to work with.  Then sketch and doodle until I come up with something.  I always like to engineer things on paper first but sometimes the ideas don't come until you start to put it together.

You've got that passion, that's the first thing you need.  From there it's giving it try.