On Tue, 11 Aug 2009 05:05:29 GMT, "Harold and Susan Vordos"
wrote:


"rangerssuck" wrote in message
...
On Aug 10, 5:13 am, "Harold and Susan Vordos" wrote:
"Ignoramus13611" wrote in message

...



On 2009-08-08, Wes wrote:
Ignoramus13611 wrote:

Has anyone tried freehand grinding of lathe bits (those with inserts
and without). The use would be a diamond wheel that cuts on the side.
I tried it with simple bits and it seems to work well, but maybe I am
missing some finer points of grinding.

Generally diamond wheels at high speed and steel do not go together.
The
steel has an
affinity for carbon which is what a diamond wheel is. Still, from
hanging out on the
Quorn groups and such, I see that people use diamond wheels on HSS.

Wes, I may be very seriously confused and misinformed. What I was
thinking about originally was carbide tipped lathe bits (with carbide
tips brazed on). When I grind those, the objective is to grind
carbide, but some steel gets ground, as well.

It's up to you to see that it doesn't. Use an aluminum oxide wheel to
grind away the steel that will get ground. Unless you use the tools for
extremely heavy cuts (unlikely), it's easiest to grind the steel at a
greater relief angle, so even if you touch steel when grinding the
carbide,
very little is exposed to the diamond wheel. Do not seriously undercut
the carbide, otherwise you risk tool failure.

Do not grind steel with a diamond wheel that runs at high speed,
regardless
of what foolish people tell you. Norton did extensive testing back in the
50's in regards to diamond and steel. They do not go together. If they
did, all grinding manuals would suggest they be ground together with
diamond.

Harold

From what I remember of reading Norton's publication on the subject:
Yes, there is a noticeable degradation of the diamond, but only in
terms of production rates. What I mean is that if you have a wheel
that will last 10,000 hours grinding carbide, and it only lasts 1,000
hours grinding steel, that's not about to be a problem for a hobby (or
even small production) user.

I don't think I'd sweat it.
--------------------------------------------------------

It's not that simple. The wheel loses performance drastically, and it
happens quickly. It's obvious if you know the difference. I'd sweat
it, and plenty, as I have in all of my years in the shop. Why taunt the
piranha? Would you also paint your car with a broom? Why not-----it's
painted, isn't it? :-)

Harold


Actually, I bought a mill that looked like it was painted with a
broom. A very old, dirty one. Right over the spooge. Don't think
I'd like it on a car.

Pete Keillor