I have cones on my jig while other designs seem to have cone on one side and flat disk on the other. I can take a bike out and put it back in the jig such that the position of the frame relative to the solid part of the jig is will repeat within less then 0.5mm when measuring the alignment of the rear drop outs. Basically right now I am using the jig as a poor man's alignment table. The bike comes out of the jig for welding and then goes back in for checking position. Like I said I get measurement repeatability of about +/- 0.5mm so for the point I am at the jig works just fine as a dual purpose device.
For now, I am using a C clamp to put a nice even pressure on the cones for clamping the frame. I am actually going to modify the jig to install a threaded rod to make this easier to manage.
My cones are steel and no damage to BB threads because they engage on the ring of the BB rather then on the threads.
https://febikes.files.wordpress.com/2011/02/sn851818.jpg?w=574
For now, I am using a C clamp to put a nice even pressure on the cones for clamping the frame. I am actually going to modify the jig to install a threaded rod to make this easier to manage.
My cones are steel and no damage to BB threads because they engage on the ring of the BB rather then on the threads.
https://febikes.files.wordpress.com/2011/02/sn851818.jpg?w=574