slowing down a bench grinder
Richard Henline
one that runs at a slower speed for sharpening chisels etc. could I slow
my grinder down by adding a regular house dimmer switch to the power
cord? If so, would this affect the motor?
Oxman
a frozen, shaved, housecat into the crook of the wheel opposite of the wheel
in which you intend to use.
Richard Henline wrote in message <3748BAA7...@earth1.net>...
Jim Mc Namara
It WILL burn it up. What happens is that the rpm's are so slow to hone a
chisel (40 rpm or close) that the starter will try and kick in. There are
others on the ng that can explain the amps, etc. to you - not an
electrician. Good luck
--
Jim Mc Namara
Kevin Singleton
Kevin
Jack-of-all-trades
I tried that method one time. The one I used had a fur ball that got
wrapped around the shaft and burnt up the motor. I won't try that method
again! <snip>
I wish to hell you people would let up on cats. I like cats. I do
think I ate some once in the Orient, didn't ask tho, and don't remember
the taste. Crocodile tasted like pork, but I think because of the way
it was cooked. Can't really recommend the baby mice wrapped in dough
however. Anyway, things like cats are starvation food, so always nice
to have one or two around.
Whether you think you can or whether you think you can't, you're
right. . .
SEARCH HERE: http://infoseek.go.com/
FAQ: http://www.robson.org/woodfaq/
Rev Chuck
rough and open. This makes the abrasive grains fewer and thus farther
apart, in effect reducing the machine's speed.
A2TONLT1 wrote:
>
> >I recently purchased a bench grinder and then saw someting about getting
> >one that runs at a slower speed for sharpening chisels etc. could I slow
> >my grinder down by adding a regular house dimmer switch to the power
> >cord? If so, would this affect the motor?
> >
> >
>
> Nearly everything I've bought with an electric motor warns you to ensure you
> have an extension cord of sufficient gauge to minimize the voltage drop along
> the cord. Presumably, 120V AC motors will not live long in a low voltage
> environment. Which is what a dimmer switch will provide.
>
> Instead, you could mechanically slow down the grinder speed by bolting a small
> pulley on the grinder shaft, and using a belt and large pulley mounted
> elsewhere with your grinding wheel. Not that I've tried this, but it seems
> like it would work.
>
> Best wishes,
> Rich Quinn
>
>
--
Nothing says you're insane like prayer.
Rev Chuck, Alt.Atheism #203, Ordained Reverend, ULC, 17 March, 1997.
Remove -REMOVE_THIS- from address to respond.
Oros2
A2TONLT1
Jim Mc Namara - Future Collectibles
Where you been? Haven't "heard" from you in a while. Good to know your
fingers are still alive!
Rev Chuck wrote in message <3748FAD4.3E19@-REMOVE_THIS-erols.com>...
>Purchase a star-wheel type dresser, and keep your stones' surfaces
>rough and open. This makes the abrasive grains fewer and thus farther
>apart, in effect reducing the machine's speed.
>
>
>A2TONLT1 wrote:
>>
Robert Peesel
> I recently purchased a bench grinder and then saw someting about getting
> one that runs at a slower speed for sharpening chisels etc. could I slow
> my grinder down by adding a regular house dimmer switch to the power
> cord? If so, would this affect the motor?
>
>
While it may seem like a great idea to lower the power going to your
grinder this way, I wouldn't consider it. The problem probably wont be
with your grinder motor, but with the small fire that could start in the
dimmer switch. These switches are not designed to carry the power needs
(amps) of your grinder. If you were to do this, expect the switch to get
VERY hot and melt.
I unknowingly plugged a computer into a dimmer switched outlet in a new
house. Once I discovered the error, I pulled the switch plate off and
found the plastic housing around the switch had begun to melt. I don't
know how far I was from having a catastrophic fire and I don't really
want to find out.
Bob
Tom Gauldin
wheel will effectively slow down the speed at the workpiece.
--
Tom Gauldin, Raleigh NC
ftp://ftp.mindspring.com/pub/users/scoundrl/gauldin.htm
Here's to the land of the Longleaf Pine,
The Summerland, where the sun doth shine.
Where the weak grow strong, and the strong grow great,
Here's to Downhome, the Old North State.
Phisherman <nosp...@poboxes.com> wrote in message
news:374d841e...@netnews.worldnet.att.net...
> I tried that method one time. The one I used had a fur ball that
got
> wrapped around the shaft and burnt up the motor. I won't try that
> method again!
>
> A dimmer will decrease the voltage and possibly burn up the motor,
as
> the motor was only designed to operate at 120v. Dimmers work on
> items that don't have motors or transformers.
>
> On Sun, 23 May 1999 20:14:37 -0800, "Oxman"
> <Royce...@email.msn.com> wrote:
>
> >It is common knowledge that the best way to slow down a grinder is
to insert
> >a frozen, shaved, housecat into the crook of the wheel opposite of
the wheel
> >in which you intend to use.
> >Richard Henline wrote in message <3748BAA7...@earth1.net>...
David Sparks
down my router? Could that be used? BTW "doo-dad" is a technical term used
only by the technically challenged such as myself.
-d
Jim Mowreader
<cdub@-REMOVE_THIS-erols.com> wrote:
> Purchase a star-wheel type dresser, and keep your stones' surfaces
> rough and open. This makes the abrasive grains fewer and thus farther
> apart, in effect reducing the machine's speed.
Rev. Chuck, I don't think that's going to slow the grinder down quite
enough.
You're looking to go from 3450rpm to 1725rpm, which is exactly half.
For that you need a jackshaft setup with a pulley on the grinder
that's half the diameter of the pulley on the jackshaft.
Or, if you really want to go crazy, get yourself a pulley (or
combination of pulleys, and lots of jackshafts) that will get the
speed down to 90rpm. Rig up a little tub for the wheel to run in,
fill it with water, and hey presto! Instant Tormek!
Ed Bennett
>I recently purchased a bench grinder and then saw someting about getting
>one that runs at a slower speed for sharpening chisels etc. could I slow
>my grinder down by adding a regular house dimmer switch to the power
>cord? If so, would this affect the motor?
Richard,
No, using a dimmer switch will not work. Yes, it will likely ruin your motor.
If it were a three phase motor then you could use a variable frequency drive to
change the motor speed and maintain constant torque. But, single phase
capacitor start induction motors do not operate well at low speeds on a variable
frequency drive. Buy a grinder designed specifically for slow grinding. There
are several available. It will probably cost less than a dimmer switch plus a
new motor for your old grinder (after you burn out it's present motor). And, it
will certainly cost far less than a three phase motor and a variable frequency
drive.
Ed Bennett
e...@primenet.com
Home of the TS-Aligner
Visit my web site: http://www.primenet.com/~ejb
Rev Chuck
Gets expensive fast. Go with a coarser wheel. You don't need a
polished grind, only a polished edge, and you get that from your
bench stones. If you're running a 60 grit wheel, go to 36, near the
halfway point in the series. Use a friable soft bond white alox
wheel for the most open texture possible.
FWIW, I'm already running a 1725 RPM machine.
Ed Bennett
>Here is a variation ... how about that little electronic doo-dad that slows
>down my router? Could that be used? BTW "doo-dad" is a technical term used
>only by the technically challenged such as myself.
Nope. The router speed control that you refer to works only on what is called a
"universal" motor. This is a motor with brushes that operates on AC or DC. The
speed of a universal motor is voltage dependent. The motor on the bench grinder
is an AC induction motor. It's speed is dependent on the frequency of the AC
power, not the voltage. Results would be the same as with the dimmer switch -
motor burnout.
Jeff Gorman
Robert Peesel wrote in message ...
> I recently purchased a bench grinder and then saw someting about
getting
> one that runs at a slower speed for sharpening chisels etc. could I
slow
> my grinder down by adding a regular house dimmer switch to the power
> cord? If so, would this affect the motor?
If the grinder is slowed below the design speed for the stone, the
stone will wear more rapidly.
Jeff
--
Jeff Gorman - West Yorkshire
Je...@millard.demon.co.uk
www.millard.demon.co.uk/Index.htm
Dave Carlson
I believe you will fry your grinder motor if you apply a light dimmer.
You really don't need a slow speed grinder to grind tools, but you might
want to look into a white or pink wheel as offered by most of the mail
order tool dealers.
You must maintain a light touch and quench often in water to avoid
burning the steel in your tools.
Probably the greatest positive impact on the quality of your grinding,
would be from the regular application of a diamond tipped stone truing
tool.
regards, Dave
Jgtimp
Date: Fri, 02 July 1999 09:33 PM EDT
Message-id: <377D6851...@newportnet.com>
Jeff:
I believe you will fry your grinder motor if you apply a light dimmer.
>>
That's right. You will fry the motor. The only motors you can put a variable
speed control on is a universal motor, such as on a router. Bench grinders have
induction motors, like on table saws. They require full voltage all the time to
work properly. Cutting the voltage will "brown-out" the motor, burning it up in
no time.
If you want a slower grinder, you have to buy a 1725 rpm grinder. Trendlines
has one (6" with white and pink wheels) for around $50 if I remember correctly.
-Jim Gott
Henry Mikkelsen
You can use a wheel with less diameter, a 5" wheel on a 6" grinder is the
same as reducing the rpm`s 18%
Henry
Chris Luebke
I have followed this thread and am suprised no one else has done what I am
going to suggest. Numerous times I have modified Buffers, Drill presses
and grinders to do what I wanted them to do.. Simply mount another entire
motor Behind your grinder, Mount what ever size pulley you will need on both
the aux motor as well as on the inside of a grinder wheel. Because of the
low speed you can use a very thin "specialty" belt.(like the old craftsman
16 speed drillpresses had) Make pulleys if you have to. I have even hung
motors off to the side of drill presses to get very very low speeds. Works
great...but you might not want to plug BOTH motors in at the same time !!!
Chris Luebke