Re: Machine Selection Guidance
Any substantial CNC router frame of sufficient size would be a good starting point. Router spindles are not appropriate for drilling steel panels, so would need to be replaced with slower spindles. Since crazy accuracy is not required, you could even use the quills out of cheap drill presses as the spindles.
Maybe set up 4 spindles on the gantry, two to drill & tap 10-32 and two to drill & tap 8-32. If you were to use ''drill-taps'' then two spindles would cover both, and if you use floating tap holders it becomes really simple. Each spindle could be on an air slide rather than a ball screw drive, use the Z drive as the master height positioning. An inexpensive 1KW servo motor would be adequate to run the spindle.
I would be looking for a used industrial class router with bad controls. You can buy these at near scrap price. All you want is the frame and the mechanical hardware. Since you are a panel shop, I assume that you also have full industrial controls and motion control design capabilities in-house. Should be a simple project.
Jim Dawson
Sandy, Oregon, USA