I think jigless makes more sense than home made jig, simply because most of the home made jigs require more stuff to make than the average home has on hand. I think a lot of folks have little idea how limited in application the actual jig is, particularly for lugged building, where it doesnèt actually hold it straight during brazing.
That said, in my mind the best homemades are: the one on Jonnycycles website, Looks like a home made Anvil, the plans Composite pro has been developing for the Frameforum comunity. And I guess the 8020 picture frame.
Most people want the Jig to:
- provide a working environment for the build, and that is mostly done by tables and vises;
- Provide an accurate reference for the assembly. This is difficult because it requires the jig to be far sturdier and more accurate than the bike. That kind of jig requires a lot of tooling to build up to that standard, and only pays back after the first dozen or so frames are made. It also imposes a lot of design limits that most jigs donèt meet: the jig needs to be built in a particular way for the various assemblies to scale off the jig. It has to reflect ideas like BB height, top tube length, etc... Any adjustible jig can be configured in space, but a jig that allows you to translate design specs to 3 d space is like an enourmous, caliper. If it doesnt do that, its partly missing in action.
- Hold the frame in place while it is welded. This is very difficult to do because the metal will move as it wants to. A jig really needs to incorporate helpful features like backpurge that might limit the damage. Many frame building techniques are going to move the tube, which is why we have cold setting rigs. Also the better jigs in this space need to provide access which means either vertical frames or huge amounts of offset from the reference surface.
I think doing the above 2-3 things is relatively practical for forks, but its a big job for frames, and in some senses less necesarry. People have jigs, what exactly they are doing is another mater.