RE: [CAD_CAM_EDM_DRO] Advice sought: Proxxon MF70 ?

On Wed, 23 Jul 2003, Dan Mauch wrote:

> Coincidentially I just bought a Proxxon MF70. I bought it for a
> microcontroller company that wanted a small lightweight machine to take

... snip ...

> I think it would be fine for wax/plastics and plaster but plaster is
> pretty abrasive as I recall. I think it will also be fine for most of
> the softer metals. I think it should be ideal for jewelers and posibly
> engravers with the 20K spindle speeds..

I do not think that plaster is so abrasive. Plaster of paris is CaSO4 with
some H2O and that must be pretty soft on the mineralogical hardness scale,
a long way below carbide and diamond and below HSS probably. I am worried
about the plastic or wax melting even at 5000 rpm (lowest with this
machine). What would you use as a lubricant/cooler for plastic or wax
milling ? Oil would dissolve the wax. Water cannot be used because of the
machine (unprotected metal), most organic solvents are out (lots of
plastic in the XY tables). I thought maybe one of the HCFC electronic
'washing' liquids would work.

Peter