Re: [CAD_CAM_EDM_DRO] High speed spindle chuck

Sounds mighty expen$ive!

I'll need to stick primarily with stuff that will be affordable to us
hobbyists!

Smoke

>Well, remember that when drilling PC boards, the plunge feed never exceeds
>about 1 Lb force, there is practically no side force, the part being

machined

>might weigh 1 Lb, tops, for a small stack of very large boards. The

machine table

>might weigh a couple of pounds, and Excellon tables float on an air

bearing.

>So, the inertia and friction loads are nil. The air bearing, integral

motor-spindle

>weighs about 6 Lbs., so a fast stroke is pretty easily achieved. The

disadvantage

>to air turbine spindles is that the speed is not constant under load,

unless

>thay have a governor on them, which the most expensive ones do, indeed,
>have. Mine has a 3 phase induction motor, but needs high frequency power.
>
>Jon
>
>