Maximum PCB Platen: Hold-Down Screws

The whole point of tweaking the Sherline was to get it ready to drill the Wouxun KG-UV3D GPS+voice PCB. While setting up for that, I drilled two #5 holes in the maximum-size PCB platen for 10-32 socket head cap screws to hold it to the tooling plate:

The sloppy hole fit lets the platen align to the tooling plate with the outer two 6-32 screws on the back edge.

Most of the PCB boards I make aren’t nearly as wide as the platen, which means the new SHCS won’t get in the way. The screws require a nut (as a spacer) to keep them from bottoming out on the Sherline’s table underneath the tooling plate and the washers are just because I can’t do it any other way; I should just shorten the screws and store them with the platen.

Masking tape holds small PCBs to the platen reasonably well, probably because I use an unreasonably high 50 mil travel clearance. I have a defunct dehumidifier that might make a dandy low-volume vacuum pump to eliminate any lifting in the middle: a project that has been on the to-do list for far too long…