and let that be a (grinding) lesson for you!

[Tony]

I've been doing a lot of fooling about / experimenting with the surface grinder.

I've got a few import "angle plates" of various sizes around and I thought I'd
turn one into a project. Get it as a square and parallel as possible.. and maybe
with some luck turn into SG tooling instead of milling machine.

These are cast iron, factory finish is a fast fly-cut.. this one has already
been ground but original squareness was about 2 thou out.



I'm measuring squareness with a surface gage and ball bearing. I need to
convert my surface gage some day, gets tiring chasing that ball around:

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My reference is a small granite 'knee'

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initial results were quite frightening.. a hair over 0.0005" out (measuring about 1.5" up).
better than before but what was happening?

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started to really worry about the result of my grinder restoration.
did I really foul this one up? had I fooled myself during the rebuild?
what could've gone wrong?

[Tony]

took a step back and had a look at the machine.
cleaned and stoned the mag chuck. wiped down all the parts, and
tried it again.

same results.. a bit over 0.0005" ..

so I decided to check my grinding vise. I knew it wasn't the bees kness
but I have faint recollection of buying it with a 0.0002" spec.

its one of these screwless types:

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measured it for the first time...

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thats 0.0015" on the side of the fixed jaw!

and 0.001" on the end face:

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so maybe this isn't a surprise to anyone.. and in hindsight I suppose it was the obvious
thing to check.. but I'll tell ya it was one hell of a roller coaster ride.

I mean the darn thing is so shiny how could it be so out-of-square?!

I plan on measuring out the rest of the vise to see if any of it is parallel / square / flat.

I don't know if I have what it takes to clean this vise up.
Especially if "what it takes" is a good vise to begin with!

[Old Hat]

Tool Making 101, Validation Validation & Validation.

Process of elimination, served you well.

[Rosco-P]

Once you know how much the vise is out, you should be able to shim the angle plate in the vise to compensate. Yes?

[boslab]

Those little rare earth magnets in the vee of the surface gauge help stop your only ball escaping under the bench!, i reckon theres a bloody spider under mine the size of a cat, the bugger eat the mice
Mark