I had the chance to get a used (very used) surface grinder and I took it.
I've never used one before so I read some of the previous threads but still
have some questions.

First, if anyone has a manual I'm willing to pay for a copy.

Main problem is this: If I hold spindle at the threads, I can rotate it
about 30 degrees before it catches the motor shaft. I can twist it back
and forth and feel it bang as it engages with the shaft. I assume there's a
key in there but I don't know how to remove the spindle from the shaft. (I
hope I'm using the right names for these parts).

Under power there is a rattling sound every few seconds which can be felt
when touching the wheel cover. This disappears completely the moment the
power is switched off and the wheel is winding down. As soon as the power
is off everything's as smooth as can be with no noises or vibrations at all.

The spindle doesn't seem to have any play perpendicular to it's axis.

A few questions:

1) The spindle only seems long enough to take a 1/2" wheel, is this true?

2) I've read about truing and balancing the wheel. But the fit between the
wheel and spindle play in it. How do you balance the wheel if the center
of the hole isn't concentric with the center of the spindle?

3) MSC has several types of diamond dressers; which point is recommended?

4) I've read about feeding in one direction only and watching the wear on
the wheel by looking at where the sparks come from. I've been feeding out
(toward me) 1/3 rev of the handwheel each pass, .033", is this OK?

5) When running the X-axis, do you go in one direction only (like you were
milling) or can you go back over the work the other way to get ready for the
next pass? I'm grinding dry.

6) How should I set the dial on top of the lube pump, and what lubricant
does it take? What other lubrication is required?

7) It came with one wheel, a Norton 32A, 8" x 1/2" x 1-1/4". The wheel is
now only 5-3/4". Do you typically use a wheel down that far? Any
recommendations for mild steel, for HSS 5% cobalt (lathe bits), for
aluminum, 6061-T6?

8) Using this wheel on mild steel, what feed rates are appropriate for .001"
or .0005" removal. I'm feeding by hand of course.

9) How much do you torque the nut that holds the wheel (or how little)?

10) Do you usually wear a dust mask when grinding?

Well, that's enough for now. I really appreciate the help.

Thanks,
David