A few years back I made my first frame at Yamaguchi and it was an amazing experience (pictures below), and I’d like to try my hand at it again, though this time I am thinking of going with a tig welded frame.
I do not have the space to work at home, but I am a member of a local makerspace which has an extensive metal shop, as well as woodshop, CNCs, a mill, and 3D printing areas. Since it is a shred space, I cant leave much if anything behind when I am not there, so was curious if anyone had ever built in a space like this. I would need my tacking jig / fixture to be somewhat mobile, so light weight is key.
I’d like to build my own jig, since this is just a hobby project, so am considering if it should be fixed for the frame I am planning, or if it would be better to build out something adjustable.
A jig like mine is highly portable. Mine is a permanent L shape you but you could easily make one that split or folded. Then it would be just a few feet long in one direction and would fit in the back of a car or on a cargo bike etc.
Hope nobody minds me “cross-posting” from a “rival” forum below.
I’d suggest you quite seriously consider not building a jig, or only building a simple “hockey-stick jig” , or a “set of matched wooden blocks” jig.
consider a set of sub-assemblies;
headtube / downtube
seattube / bb shell
chainstay / dropout ( both of both if you have chain stay bridge )
each on their own is simple enough to mitre, fixture, and tack on a bench / in a vise, and then, mitring the “other end” of the DT and CS isn’t too complicated if youve drawn some good centerlines.
at which point either a simple flat layout on a drawing, or a hockey stick jig is plenty for a tig welder.
(a hockey stick jig is something like a hockey stick (long, straight, flat) with a hole drilled in it at one end; using some tube blocks or simple spacers, you can clamp it to the side of the head tube, clamp it to the side of the seat tube, and put a dummy axle (oft a big of threaded rod and an assortment of hex nuts) through the hole, to hold the dropouts in the right place.
the matched wooden blocks idea is something like a bunch of 2” x 4’‘ x 6” blocks, with holes drilled through them to match all your tube sizes ( or just v’s cut into one side ) with centrelines at a fixed distance from one end. with each stood on end, and the tubes in their correct holes, the array of blocks suspends your frame that same fixed distance off a flat surface; stays get a bit funny but dropout notches and a handful of wedges make it easy
my 2c is that unless you WANT to BUILD a jig, don’t let it get in the way of building a frame.
a mate of mine built a one-off jig for the front triangle of a FS frame, by simply cutting the inside silhouette of his front triangle out of a sheet of 19mm” MDF, drilling some holes in it, and then zip tying all the tubes to it…
Posted elsewhere but consider just the front half of this. Draw full size, glue down 1x2 strips. Add spacer strips underneath to match centerline of tubes and hold it all down with bits of perforated pipe strap and screws over top of tubes. 3 (4?) tandems were built on this back in the 80s and they worked out fine. I actually mitered the tubes first and built the fixture around them.
If the workspace has a sufficiently large surface plate, I would look into the frame fixtures Alex Meade makes and sells:
Not too expensive, small and mobile (esp if you found a case it would fit well into), highly adaptable to various frame sizes/styles/tubing shapes/etc, and could also be replicated w/o too much effort if you’re committed to making your own.
I agree with @crowe-molybdenum, since I have various jig sub-assemblies like chainstays/seatstays, I use the full jig much less. My suggestion is to buy the fixtures for chainstays/seatstays and then build one for the main triangle (that you can build flat).
They would be much easier to transport and you can transport one at a time depending on what you will be working on that particular day.
I have been working on building a bike frame in a Maker Space for the last few years. Had some delays (maker space moved) in the last year.
If they have storage space / area you can rent I would highly recommend it. I tried for about a year with bringing stuff back and forth and the deeper you get into it, the more stuff you acquire and have to bring to and from.
I built my own jig. It’s the Peter Verdone Skynet jig. Fairly simple compared to some out there, but it works with the common 2”x2”- 5/8” diameter hole, flat surface. You will need to have a milling machine and lathe to build it though. A DRO will make things a lot easier as well. I do not have a DRO on the milling machine I have access to.
I also built a bunch of other jigs. Chainstay and seatstay mitering. Tube mitering. Others. If you have the money though I would maybe suggest buying some to save time on fabrication. But building tools can be fun as well. For instance, there was a Farr chainstay and seatstay mitering jig for sale here a couple weeks ago for $700. That is something I would have bought instantly a couple years when I was considering chainstay and seatstay mitering tools. $700 is definitely worth the time, effort, and materials it takes to build a tool of that quality and usage.
The alignment part of the process typically requires the heaviest piece for leverage. I still haven’t figured out what I’m going to do for alignment, but I may use the table of the milling machine I have access to. I don’t want to damage it though. If you have an idea, please let know!
Ted, I use a makers space for my mitering, brazing and head tube reaming. Like some of the others noted, transporting items back and forth ended up getting pretty annoying. So, I picked up an older Pelican case, did a 3d layout of the fixtures/jigs and tools I would have at the space, and had custom cut-out foam for the tooling made. I pay a minimal storage fee to keep my tools there, and it’s secure. My frame fixture an TIG machine is at home, I could move the fixture there at some point and use the TIG machines at the maker space, but for now, I have a setup that works fine.
