side-by-side bike

I've always wanted to build a side-by-side bicycle, and I finally
found an excuse a couple weeks ago. Here's some pictures:
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Reply to
Dave Wilson
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Hey, you're just the chap I want to talk too.
Welding thin bike frame tubing? How easy was it with a Mig? I'm going to build a recumbent from old bikes and do not have the facilities to store oxy/act. I figured I might just be able to get away with mapp/air, but It's going to be tricky. Fine for smaller stuff, but doing a fillet braze might prove difficult. I'd been steered away from a stick or mig welder, but you obivously had no trouble blowing holes in the tube......but you're probably an experienced welder anyway :-)
Enjoyed looking at that.
Garry
Reply to
Garry Broad
[...]
I was using 4130 tubing that came in a box of practice tubing from a homebuilt airplane company. I had no problem welding that with my 110v mig. I also used 1" EMT, which I would occasionally blow through, but it was easy enough to fill it in. My welds were strong enough, but they were not pretty. At least they were shiny and non-porous, with good penetration.
I like oxy/acetylene brazing to join EMT, but it takes a little longer to light the torch, adjust it, and get the rod in place, then it does to just pull the trigger on a mig. The brazing looks a lot better, though. I have a little plumber-style oxy/acetylene pair of bottles, and I think that would be plenty to do a bike. When I took my welding class, one of the things I would do to prepare was fishmouth a whole bunch of EMT, then take it in and braze and weld it together. If it's fitted and jigged, it's really not that hard.
That was when I was thinking about building an airplane, before I decided I had better things to do for the next three years. I don't know what an FAA inspector would say about a mig-welded fuselage. I don't think it would really cut your build time by much, though.
Dave Wilson
Reply to
Dave Wilson

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