Someday, I’ll have to post a full writeup on the details of this frame fixture, but for now I just wanted to comment on how cool the tubeholder is. With any fixture it seems to me that unless you’re building a lugged frame (tube-holders ‘built-in’) it is really nice to have a way to at least steady the tubes against eachother so they don’t fall on the ground – which is at least a loud racket and at worst dinging themselves making you put them into the smaller-frame-size-tube-bin. I have absolutely no ability to make my own tooling. I have no lathe, a cheap mill/drill, and a belt-sander – and most of all no training. Making something somewhat round and faced is hard enough let alone making a fixture for anything that’ll turn out straight. Sure, there’s the aluminum extrusion stuff that I have yet to try but I honestly just want to make bike frames – that’s just me. Anyways, I’ll agree that fixturing is a fun problem to solve with home-made fixtures and even with my old HJ Access 65, but having such a well thought-out tubeholder on the JMan is a really nice luxury.
The tube holder arm pivots around the center of the frame fixture and extends in/out with an orange handled tensioner. There’s an arm that screws on at a 90 degree angle to mount the various tube-holders. There are little round holes as seen in the picture so that the main-tube-holder attachment is centered properly. The main tube holder is spring loaded so you can just lift the handle and swivel it to plop against the tube and it’s set. It doesn’t tighten up against the tube, the spring tension just holds it there so it doesn’t drop or move while mitering the other tubes or tacking. The other attachment I have not used is for seat stays or chainstays, but it’s basically two plates that sandwich the tubes together holding them in place but allowing for lateral movement to take the tube out to miter. The quality is just stunning on this thing and it truly does make it more time efficient to build a frame when you only have a couple hours a day to get into the shop to work.
There’s a couple random pics in there too un-fixture related just to show and tell. I’ll write something up on what i learned from Don on pulsed tig-welding technique but I’m not sure it’s news to anyone but me!