Re: [CAD_CAM_EDM_DRO] HF spindle sources

Graham Stabler wrote:

>I have a smallish (6") precision XY stage from Parker Daedal and have
>just got a Z axis sorted for it. It should be pretty accurate and I
>intend to use it for some engraving and the manufacture of very small
>parts.
>
>What it does need is a decent high speed spindle. There is no point
>sticking a Dremel on it.
>
>Does anyone know of any HF spindles that will not absolutely break
>the bank? It doesn't need to be excessively large.
>
>

Search eBay at least every 3rd day using search strings like "high speed
spindle".
I have seen a number of Westwind air bearing spindles (Mostly PCB drilling,
but some milling spindles too) and Rockwell/Precise spindles (mostly ball
bearing, with interchangeable collets). I got a Rockwell/Precise ball
bearing
spindle last year for something like $75.00 (but I can't find the eBay
messages,
so I might have paid more). Anyway, you usually don't get the frequency
converter with these. The Westwind units are 3 phase, and a standard VFD
will drive them up to 400 Hz (24,000 RPM) with just 3 inductors in series
with the motor wires. The Rockwell/Precise spindles are 2-phase, and in
theory a standard VFD should work by using a Scott-T transformer. I
haven't tried this yet, but I will have to set it up sometime and see if the
VFD handles it OK.

Jon