I made this fixture to align the holes in the neck for the barrel connector. It's pretty simple but it does the job. I've dedicated these two drill bits to this operation, so the stop collars stay on and there is very little setup involved. Just clamp the squared-up neck blank into the fixture, chuck the bits into a cordless drill one at a time, and drill until the stop collar hits the fixture. Careful use should keep the guide holes tight and accurate, but if I had access to a machine shop it would be even better made out of metal.