"DoN. Nichols" wrote in message
...
On 2011-08-19, Ignoramus20025 wrote:
First of all, how often are surface grinders needed in the context of
buying-repairing-selling of machinery or general screwing around?

You could use it to make a precise spacer to go between bearings
for the proper pre-load. Or shims to space something just right. Or,
if you want a really flat surface for something.

Second, say, I wanted to resurface the face of an anvil. How long will
it take to do with something like a Boyar-Schultz 612 Deluxe surface
grinder (non-CNC)? Taking off, say, 50 thousandths from a face of an
anvil.

50 thousandths -- Hmm ... you might be able to 0.0005" depth per
pass, so figure 100 passes to reach your depth. And figure a *lot* of
passes to go across the face of the anvil, since you don't cut across
the full width of the stone at a time. Maybe 0.050" per pass at a given
depth. If the machine has automatic feeds, you can set it up and read
something while you work -- but you want to be there to hear if it
starts to bind. You'll probably need to dress the wheel a few times
during that 0.050" depth of cut. (Harold should drop in here and give
*real* figures.)

My biggest concern would be the weight of the anvil. If it's not large, it
would work reasonably well, assuming the machine has hydraulic feed.
Cranking the weight by hand would get old fast.

Depth of cut, assuming one has coolant, and uses the right wheel, could be
as great as .008" per pass, but with modest step-over. I'd suggest
something like .03" per pass. It goes pretty fast that way. The wheel may
require dressing after each pass, or not. It's pretty easy to know when
it's time, as the crisp edge of the wheel deteriorates, causing the cut to
labor. Coolant would be almost a must, although with the mass of an
anvil, a lot of heat could be absorbed.

Surface grinders are wonderful machines if applied properly.

Something to consider. Motors on precision grinders are not of the common
variety. They are generally precision balanced, and should not be replaced
by single phase motors, even if they are balanced. The pulsation of the
single phase motor will generally manifest itself in the surface finish.
If you can't provide three phase power, I'd suggest you not get involved
unless absolutely necessary. You're bound to be disappointed.

Grinding is an art. You can work to .000050" with a good surface grinder,
but you must have a firm understanding of proper procedures. One must not
be ham handed.

I think that a Blanchard grinder might be a quicker way to
get most of that 0.050" off
I agree, assuming one is at disposal. They're a real work horse.

Harold