Fabricating my own frame jig - 8020 questions

[anon.]

See Alex Meade's site for a setup very similar to what I use, less the surface plate: Tools

Alex actually made those pieces for me. They work wonderfully for putting a main triangle together, but tacking the rear is an ever evolving-process.

The blocks all have etched centrelines so I can build easily off of a full-scale drawing or BikeCAD printout:



I think I spent about $600 on the lot, which hopefully paid Alex a fair wage for his time.

[EnginCycles]

Alex actually made those pieces for me. They work wonderfully for putting a main triangle together, but tacking the rear is an ever evolving-process.

The blocks all have etched centrelines so I can build easily off of a full-scale drawing or BikeCAD printout:



I think I spent about $600 on the lot, which hopefully paid Alex a fair wage for his time.

If I was building with this process I would attach the chainstays to the BB shell as my first step. You can fixture them up flat and they are one of if not the most important part of the equation for alignment. Once they are attached (and you set the drop out angle correct) just load that BB shell and rotate until the angle of the chainstay matches your drawing and proceed with the bike. I think it would be very accurate and easier to fixture (this is all assuming your blocks are far enough away from the surface to allow 1/2 the width of the drop outs, which is does appear).

$.02

[pruckelshaus]

I would ask this guy how big his cast iron surface plate is and if he has pictures. There is also a 4'x4' granite plate down near the Delaware border

Thanks for the lead. I emailed the Scranton guy. The 4x4 table scares me...but the price sure is right.

[anon.]

If I was building with this process I would attach the chainstays to the BB shell as my first step.

That's exactly how i've been doing it for the last few frames I've made on this set-up. Tack the stays to the shell, check alignment, then do the main triangle.