Grinder Confusion. Fast?? Slow??

[Ken Massingale]

O.K.
I was ready to get the Woodcraft slow speed grinder, then in the instructions that came with the Oneway Wolverine Jig, they state, with explanations, that a 8", 3450 rpm grinder is best. Below is a scan of their statement.
Now, I'm confused, but leaning toward following their suggestion.
I'd appreciate comments on this.
Thanks,
ken

[kwgeorge]

Personally Ken I prefer the variable speed model that I bought but here is my thoughts on this. When grinding Carbon tool steel a slow speed grinder is more desired as it will not heat up the metal as fast and with HSS it is nice for more precise shaping of the tool since it does not remove metal as fast. Now when I am profiling a tool I like the high speed so I can remove a lot of metal quickly and get to the shape I am after then I slow the grinder down and refine the shape. Most professional turners such as Alan Lacer, Mike Mahoney and Richard Raffan all suggest a grinder above 3000 rpm. Since I still do other things with my grinder besides sharpening turning tools I decided the Delta Variable speed was the ticket for me.

[mudder]

Ken,

Grinder speed in my opinion is less important than wheel selection. You should have an aluminum oxide wheel instead of the "grey wheel" that comes with most cheap grinders. I personally have the Woodcraft slow speed grinder and I can determine no difference in edge quality from the variable speed Delta that my club uses. It takes me a few seconds longer but I'm not out to break any speed records.

This is my opinion and I'll stick to it.


P.S. I now use a Tormek for most of my sharpening.

Mudder

[Whit]

Ken, did you get the Delta GR450, variable speed? I picked one up a couple of weeks ago and finally used it yesterday. After about 30 minutes of grinding to shape some HF tools(using your technique that was mentioned in an earlier post) the motor on the grinder was so hot I could not hold my hand on it. Picked up another one today. It just gets warm, but on start up it makes noise like something is loose, but when it gets up to speed, it is smooth. I wonder if a field winding is loose? Did you have any problems with yours????
Whit

[kwgeorge]

Nope, not a problem here at all. Mine does not get hot either but does get a bit warm but no more than any other motor. The only problem that I had was the rough grit wheel was warped but I changed both of them out anyway. Sounds like you are having some bad luck on those grinders. Very strange.

[boblon]

Hmmm. I have the Delta VS grinder too. Mine does get real hot after a short while. I assumed this was normal?

BobL.

[Mort]

I got the Woodcraft slow speed - third time is the charm for me - and am very pleased with the tool in use with the Wolverine System to include the Vari Grind jig. The 8" x 1" 80 and 120 grit aluminum oxide stones included with this grinder is a plus. FWIW all of the turners in the Sarasota Wood Turners club use a slow speed grinder for sharpening gouges. They also have high/VS grinders for shaping.

[Ken Massingale]

Thanks guys. I off to Woodcraft to grab the slow speed.
ken

[tribalwind]

i had picked up the Ryobi 8" from home depot..2 weeks and maybe 6 uses later it burned itself out,,i returned it to HD and got another one just because i wanted something right away but i will be returning it by mid january or sooner if i get a new grinder by then.just dont trust it now.
maybe ill look at the VS models. thanks for all the ideas'

[Ken Massingale]

*&^%$#@!
Gotta take it back, dang thing runs backward. Another 80 mile round trip.
ken

[mudder]

quote:Originally posted by Ken Massingale

*&^%$#@!
Gotta take it back, dang thing runs backward. Another 80 mile round trip.
ken

[}] pull the covers off and turn the thing 180 degrees. That will work except for having to run around the machine to turn it off. [}]

That's amazing. I've never heard of this type of motor running backwards.


Mudder

[Whit]

I think the problem(getting hot) with the first Delta grinder was due to bearing problems. It took 30 seconds to stop after turning the switch off. The new one takes 3 MINUTES to stop. I assume that the bearing drag was causing more current draw therefore more heating. I am now a happy camper.
I am also very happy with the new Wolverine jig.
Whit

[Ken Massingale]

quote:Originally posted by mudder

quote:Originally posted by Ken Massingale

*&^%$#@!
Gotta take it back, dang thing runs backward. Another 80 mile round trip.
ken

[}] pull the covers off and turn the thing 180 degrees. That will work except for having to run around the machine to turn it off. [}]

That's amazing. I've never heard of this type of motor running backwards.


Mudder

Neither did the folks at WC when I called them to say I was bringing it back. The windings were absolutely bad. At power on, it would hum a bit, then take off backwards. I found that I could give it a spin in either direction and it would go that way.
They got a kick out of it back at the store.
The newest one is just fine, except the wheels are bad out of round. I'll fix that in the morning.
ken

[Mort]

Wierd on the reverse turning of the grinder. Might have been a keeper for the novelty. Oneway's wolverine installation instruction specify center line shaft height and holder positioning vis a vis the wheels. I suggest following those instructions.DAMHIKT

[Ken Massingale]

quote:Originally posted by Mort

Wierd on the reverse turning of the grinder. Might have been a keeper for the novelty. Oneway's wolverine installation instruction specify center line shaft height and holder positioning vis a vis the wheels. I suggest following those instructions.DAMHIKT

I was very precise in the height and positioning the bases centered with the wheels.
I also aligned the front of the bases with the front of the wheels as specified, but I can't figure why that is critical. The front of base to front of wheel alignment is gone as soon as the wheel wears, and I can't see any application where the vee arm would be slid up to contact the front of the base. I'm a bit thick in stuff like this, tho.
ken