One thing I wish I had done better when I made my jig was machine in some marks for some critical dimensions. For example, I put a slot that allows you to measure from the center of the bb post in both the vertical and horizontal directions. However, I should have repeated these at intervals, particularly the horizontal position of the center of the bb shell. It's one thing to hold a batch of tubes together, but what you want is to hold a batch of tubes in particular places. That means that measurements are key. It's very easy to make mistakes in measuring

It's also nice to be able to proof the fixture by putting it on a table. The king of this method is the Sputnik, the downside is that there is a huge flat plate in your way when actually using the fixture. One thing I noticed with mine is that I have to be careful to make sure everything is tight and the moving parts are flat relative to each other.

I think it's a pretty sensible design, unlike the kickstarter designs. And only twice as much The kickstarter design I'm familiar with is good for people that want to say they build frames but never will.