[sdiy] PCB fab house to make synth panel?

[Paul Schreiber]

> I don't know much about CNC machines, but I would guess that different 
> bits
> are needed for machining aluminum rather than machining PCB stock. PC 
> boards
> are drilled with teeny holes, mostly; panels are drilled with large holes
> (or small bits are used to cut large holes). So it would be more than just 
> a
> matter of changing materials.

Most people don't realize that most pc boards (when drilled), the boards are 
stacked 4-8 at a time. I have seen them stacked 20 at a time for larger 
holes.

The drills are spinning at around 130,000RPM using air turbines. There is so 
much mechanical inertia, the beds of the drill platens are usually 6" thick 
granite, and you have to bolt them to a 10" thick concrete poured floor or 
the "hopping" will break the bits off. And, they can drill a single 0.018 
hole (typical via size) through 6 stacked 0.062 boards in about 700us (yes, 
us).

Paul S.