Thanks bub, it's my trade-bow-in-the-works.
RB, do you mean the bow will flip to one side or the other of the clamp? If so, it's probably because you're tillering a reflexed/recurved bow. If you look at the first pic, the bow I'm working on has a bit of recurve in the tips. It wanted to flip in the jig. In the initial stage of tillering, the bow will be unstable because the tips are lower than the handle (point of application of force). It's just like bracing a recurve with the push -pull method. At first, you need to hold the bow firmly so it doesn't flip or turn around in your hand. But as you pull, the handle goes past the tips and it doesn't want to flip anymore. Same thing with the pillar jig. If you don't want any problems from start, make sure the string is tracking in the center of the handle. Then, if tracking is good or nearly so, the problem goes away when the bow bends a bit and the handle goes under the line of the tips.