Hello,
when grinding tools the fast grinders with ~2000RPM are usually bas
because they overhet the steel, so one goes ond uses slow ones with
water cooling.
What now if one water cools a fast grinder? Is it possible to
dissipate the head well enough to have the steel still cool enough to
keep it hard? After all you still have sparks coming off the grinding
wheel.
Are there besides the mess you create other drwabacks to be
considered, such as grindstones not being water resistant?
--
Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
mailto:[email protected] Phone: +49 228 73 2447 FAX ... 7869
Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23
Juergen Hannappel wrote:
> Are there besides the mess you create other drwabacks to be
> considered, such as grindstones not being water resistant?
Slinging water at high speed at an electric motor that wasn't designed to be
exposed to such comes to mind as a potential problem.
I'd say it would not be sufficient just to bathe the wheel in a bowl of
water either. The water would heat up, and as it did so, it would be able
to carry heat away less and less efficiently. Seems to me if you want to
do it fast, you'd need some kind of reservoir and pump mechanism to move a
lot of water through, spray it on, capture it, then maybe somehow filter,
cool, and recycle it. Or maybe hook it straight to the tap on the supply
side, and flush the waste out into the garden or something.
But personally, I hate everything about grinders anyway. I use a belt
sander for power work, and follow up by hand.
--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/
http://rosegarden.sourceforge.net/tutorial/
You will never keep the water on it. In any case, a regular high speed
grinder can be used quite effectively to grind plane irons, chisels, ect.
That's all I use and never have a problem.
"Juergen Hannappel" <[email protected]> wrote in message
news:[email protected]...
> Hello,
> when grinding tools the fast grinders with ~2000RPM are usually bas
> because they overhet the steel, so one goes ond uses slow ones with
> water cooling.
> What now if one water cools a fast grinder? Is it possible to
> dissipate the head well enough to have the steel still cool enough to
> keep it hard? After all you still have sparks coming off the grinding
> wheel.
> Are there besides the mess you create other drwabacks to be
> considered, such as grindstones not being water resistant?
> --
> Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
> mailto:[email protected] Phone: +49 228 73 2447 FAX ... 7869
> Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
> CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23
On Sun, 07 Nov 2004 11:54:21 +0100, Juergen Hannappel
<[email protected]> wrote:
>Hello,
>when grinding tools the fast grinders with ~2000RPM are usually bas
>because they overhet the steel, so one goes ond uses slow ones with
>water cooling.
>What now if one water cools a fast grinder? Is it possible to
>dissipate the head well enough to have the steel still cool enough to
>keep it hard? After all you still have sparks coming off the grinding
>wheel.
>Are there besides the mess you create other drwabacks to be
>considered, such as grindstones not being water resistant?
I use a cup of water and a small water spray bottle near my grinder.
Grind a little, then apply water to the part. I would not put water
on the grindstone (use a waterstone instead).
It is not practical to water cool a high speed grinder. The motor is not
sealed against water and it could short out. Grey grinding wheels while
water resistant are not waterproof. The resulting sludge is not good for
cast iron and steel grinder parts.
I like to use white grinding wheels. The cement that holds the wheel
together is softer than grey wheels as is the abrasive itself. White wheels
are soft enough for the grains to break while you are sharpening. This
results in sharper particles cutting faster and therefore cooler. The wheel
needs to be dressed more often but it is safer for high carbon steel. You
still need to have a bucket of water next to the grinder and continually dip
the blade between short grinds. It is not needed for high speed steel which
holds it's temper well when hot.
max
> You will never keep the water on it. In any case, a regular high speed
> grinder can be used quite effectively to grind plane irons, chisels, ect.
> That's all I use and never have a problem.
>
> "Juergen Hannappel" <[email protected]> wrote in message
> news:[email protected]...
>> Hello,
>> when grinding tools the fast grinders with ~2000RPM are usually bas
>> because they overhet the steel, so one goes ond uses slow ones with
>> water cooling.
>> What now if one water cools a fast grinder? Is it possible to
>> dissipate the head well enough to have the steel still cool enough to
>> keep it hard? After all you still have sparks coming off the grinding
>> wheel.
>> Are there besides the mess you create other drwabacks to be
>> considered, such as grindstones not being water resistant?
>> --
>> Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
>> mailto:[email protected] Phone: +49 228 73 2447 FAX ... 7869
>> Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
>> CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23
>
>
Juergen Hannappel <[email protected]> wrote in message news:<[email protected]>...
> Silvan <[email protected]> writes:
>
> > Juergen Hannappel wrote:
> >
> >> Are there besides the mess you create other drwabacks to be
> >> considered, such as grindstones not being water resistant?
I spent most of a Summer operating a Centerless Grinder... 5,500 RPM
grinder water cooled designed for turning the grip(shank) on Aerospace
quality stainless steel (A286) bolts and screws .. (really boring job)
The biggest issue by far was the fact that the wheels had to be
specially designed to operate wet..
1) they had to be uniformly porous or they would go out of balance (
huge issue with a 90 lb wheel turning 5500RPM, probably less an issue
for your requirements)
2) they had to use some sort of special composition (sorry I can't
remember exactly what) to keep the wheels from turning into mush.
3) They had to constantly be re-dressed because they would clog really
fast.
However I could hold tolerances to 0.00025" without ever burning a
part.
In short yes it is possible but be sure of your wheel, standard wheels
are probably not good enough.
>How does the belt sander cope with the heat problem? After all the
>heat in the steel and not the temperature of the wheel is the problem!
>
the belt does get hot. this ruins it faster then the actual grinding alone does.
this is why the longer the belt the cooler it grind and the longer it lasts.
my 6x48" belt sander runs at 1750 and does fine. my 6x89 runs at 3400 and does
fine too. but if you ran that shorter belt at the same speed you would get far
more burning.
--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com For prices and ordering instructions.
High speed grinding is done all the time in metal working shops. Surface
grinders, center crinders and centerless grinders all user high speed wheels
drenched in coolant to take the heat away (in fact, special coolants - about
97% water with rust inhibitors etc - are made just for grinding). All these
types of grinders throw so much coolant around you really can't see the
actual part to wheel interface - I don't think you could see what you were
doing if you tried to hand hold a part with enough coolant to stop it
burning up.
Also, most these grinders take extremely light, controlled cuts - hand
holding is not very controlled by these standards.
Ian
"Juergen Hannappel" <[email protected]> wrote in message
news:[email protected]...
> Hello,
> when grinding tools the fast grinders with ~2000RPM are usually bas
> because they overhet the steel, so one goes ond uses slow ones with
> water cooling.
> What now if one water cools a fast grinder? Is it possible to
> dissipate the head well enough to have the steel still cool enough to
> keep it hard? After all you still have sparks coming off the grinding
> wheel.
> Are there besides the mess you create other drwabacks to be
> considered, such as grindstones not being water resistant?
> --
> Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
> mailto:[email protected] Phone: +49 228 73 2447 FAX ... 7869
> Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
> CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23
On Sun, 07 Nov 2004 09:38:47 -0500, Silvan
<[email protected]> wrote:
>
>Slinging water at high speed at an electric motor that wasn't designed to be
>exposed to such comes to mind as a potential problem.
Maybe you're talking about something else, but I used a
powered dual grinding wheel years ago in a car repair
shop I worked in where one wheel sat in a water trough.
The shape of the trough minimized splashing.
Silvan <[email protected]> writes:
> Juergen Hannappel wrote:
>
>> Are there besides the mess you create other drwabacks to be
>> considered, such as grindstones not being water resistant?
>
> Slinging water at high speed at an electric motor that wasn't designed to be
> exposed to such comes to mind as a potential problem.
That's *not* the problem, the spray goes away from the motor.
>
> I'd say it would not be sufficient just to bathe the wheel in a bowl of
> water either. The water would heat up, and as it did so, it would be able
No. The quickly spinning wheel transports away some of the water which
has to be replaced all the time, so it does not really get warm,
[...]
> But personally, I hate everything about grinders anyway. I use a belt
> sander for power work, and follow up by hand.
How does the belt sander cope with the heat problem? After all the
heat in the steel and not the temperature of the wheel is the problem!
And of course i sharpen by hand, it's rather a question for cases like
removing *very* bad nicks in a blade or reshaping a blade completely
when several mm of steel have to go.
--
Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
mailto:[email protected] Phone: +49 228 73 2447 FAX ... 7869
Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23