Grinder Confusion

[Ken Salisbury]

I recently purchased a 6" VS Delta Grinder to sharpen my lathe tools. Today I recieved my Wolverine and Varigrind jigs. Lo and behold the new grinders base has a couple of flanges to the side which interfere with the Wolverine jig bases so that the base cannot be lined up directly under the wheels as required in the Wolverine instructions - so I need to return this grinder and select another one. I will probably look for a suitable 8" one.

Now cometh the confusion. I was under the impression that a slower speed (1725rpm) was better for grinding lathe tools than a higher speed (3450rpm). While reading the One Way Wolverine instructions I found the recommendations information (attached hereto) which disputes that theory. What is a fella to believe ?

"Old Dog" needs to learn a new trick ! !

[Charles Bjorgen]

I ran into the same state of confusion after buying my Wolverine system. I did have the advantage of talking to the people from Oneway when the 2001 AAW symposium was held in St. Paul. The guy I talked with on the subject stands by his position that a high speed grinder turning at 3450 rpm is the most efficient use of a grinding wheel. However, most turners I talk with still prefer the so-called slow speed units. I chose the seven-inch Baldor slow speed unit and have been entirely satisfied with it. Seems to me the choice of proper friable aluminum oxide wheels in "J" or "K" hardness might be more important than grinder speed.


I recently purchased a 6" VS Delta Grinder to sharpen my lathe tools. Today I recieved my Wolverine and Varigrind jigs. Lo and behold the new grinders base has a couple of flanges to the side which interfere with the Wolverine jig bases so that the base cannot be lined up directly under the wheels as required in the Wolverine instructions - so I need to return this grinder and select another one. I will probably look for a suitable 8" one.

Now cometh the confusion. I was under the impression that a slower speed (1725rpm) was better for grinding lathe tools than a higher speed (3450rpm). While reading the One Way Wolverine instructions I found the recommendations information (attached hereto) which disputes that theory. What is a fella to believe ?

"Old Dog" needs to learn a new trick ! !

[Glenn Clabo]

Ken,
There are a ton of studies and opinions on this one. It has to do with grind and feed rate which will equate to a resulting surface microhardness. However, from an old machinist who has done a bunch of sharpening...if it's running slower it's harder to burn up. If you don't heat it up you don't ruin the temper. It's simply safer...and reduces the possibities of failure.

There are a bunch of people who actually do calcs to determine the wheel rpm on given places of the wheel. I think it's about feel and comfort.

Of course that's just from this old dog.

[Tom Sweeney]

I just got home from stopping at Woodcraft, on my way home from work, & plopped down $79 (w/tax) for their 8" slow speed grinder with the good wheels - white - I don't know what grit or what kind but they're supposed to be the good ones.

Now I log on and the Old Man says I bought the wrong one :confused:

Oh well It's got to be better than what I'm currently using & you can't beat the price - I think I'll stick with what I bought.

[Bobby Hatfield]

I recently purchased a 6" VS Delta Grinder to sharpen my lathe tools. Today I recieved my Wolverine and Varigrind jigs. Lo and behold the new grinders base has a couple of flanges to the side which interfere with the Wolverine jig bases so that the base cannot be lined up directly under the wheels as required in the Wolverine instructions - so I need to return this grinder and select another one. I will probably look for a suitable 8" one.

Now cometh the confusion. I was under the impression that a slower speed (1725rpm) was better for grinding lathe tools than a higher speed (3450rpm). While reading the One Way Wolverine instructions I found the recommendations information (attached hereto) which disputes that theory. What is a fella to believe ?

"Old Dog" needs to learn a new trick ! !

Ken, I agree with that other old shop dog, Glenn. Having ground up a few too many high-speed tools on a grinder, along with a few carbide ones, I like a nice 10" wheel at slow rpm but most were in the neighborhood of 3250 and used them anyway, just got off quicker cause they ground off lots of metal fast and it got hot fast and you just get used to it and live with it, burned fingers and all. Its just something you will learn, while doing the job. Keep cool water close, mostly for the fingers. The (surface feet per minute) is the critical factor, along with a sharp wheel, of course both can be off and still get a sharp tool.

[Kevin Gerstenecker]

Ken, I recently bought the exact grinder you have. I also ran into the base flange interfering with the placement of the Wolverine System bases. Not wanting to return the grinder, I just removed the factory feet on the Grinder, cut a piece of Oak, for a spacer, thick enough to clear the mounting brackets for the Wolverine System, and it worked out just fine. I also though I was not going to be able to use this grinder, but a few minutes of thinking about the situation allowed me to come up with this remedy. I used long screws to mount the grinder to my bench, and I ran them in at an angle to clear the Wolverine Bases, and it holds the grinder just fine, and the jig works perfectly. This grinder is only used for my Turning Tools, so it doesn't have to be bolted to withstand a Tornado, just be secure to eliminate any movement, and this solution works just fine. Just an idea, but you may want to do things differently. As far as the grinding speed goes, my Uncle, the Cabinetmaker who does all my blade sharpening, also has been in the sharpening business for many years. He does an excellent job, and he also says that slower is better for sharpening, especially with HSS and the other alloys now used for most cutting tools. He told me to use my grinder on the slowest speed to get the best results on my turning tools. But, like many other Woodworking issues, everyone has their own idea on what is best...........I say go with what works for you. If you would like, I can shoot a picture or two of my solution with my Delta VS 6" Grinder and email it to you. Just let me know! :)

[Anthony Yakonick]

It's sorta like black magic if it works for you, use it! In ten years of turning I've used both types I nowhave a Woodcraft slow speed and the Oneway jigs.

Anthony

[Jim Becker]

I just got home from stopping at Woodcraft, on my way home from work, & plopped down $79 (w/tax) for their 8" slow speed grinder with the good wheels - white - I don't know what grit or what kind but they're supposed to be the good ones.

Now I log on and the Old Man says I bought the wrong one :confused:

Tom, I prefer the 8" format for grinding tools as it doesn't create so extreme a bevel. While it is true that HHS will sharpen just fine on the 3600 rpm units, the 1725 is a little more forgiving, especially as you are learning to sharpen. So...don't worry about your purchase! It was a super deal for a grinder that will do a great job for you. (I wish I had one of the slower ones for reshaping chisels and other tools that are not HHS...)

[David Peebles]

Hello Ken,

I just bought the Woodcraft 8" grinder. I had a 6" for several years that worked just fine. But as the wheels got smaller, it did change the shape of the gouge bevel. These were both slow speed. I am not sure why Oneway prefers the high speed grinder. For me, I love the slow speed. It just seems to be more relaxed when sharpening.

I have used a high speed grinder at demos that I did. I found no difference in the finished edge from the slow speed. I would like to know how it was decided that the high speed is better. Slow speed seems to work for me.

Best,
Dave

[Mike Evertsen]

Can a speed control be put on a grinder like the one they have for routers????

[Phil Phelps]

Tom, I prefer the 8" format for grinding tools as it doesn't create so extreme a bevel. While it is true that HHS will sharpen just fine on the 3600 rpm units, the 1725 is a little more forgiving, especially as you are learning to sharpen. So...don't worry about your purchase! It was a super deal for a grinder that will do a great job for you. (I wish I had one of the slower ones for reshaping chisels and other tools that are not HHS...)



Well stated, Jim.

[Jason Roehl]

Well stated, Jim.

I agree with Phil and Jim.

[Ron Meadows]

I agree with Phil and Jim.

I agree with Phil and Jason, and especially Jim


Ron

[Richard Allen]

Hi Ken

Oneway is right about the speed. The wheels will cut better and last longer at the higher speed. The slower speed will leave deposits on the wheels requireing that you dress the wheels more often. So to get the best use of the wheels the grinder should be the high speed grinder.

I am not sure the goal is to get the best use of the wheels. Perhaps the goal is to easly grind sharp edges on your lathe tools. For many the slower speed is best for that goal.

Thanks

[Dan Stuewe]

Can a speed control be put on a grinder like the one they have for routers????

Mike, the speed control works on a universal motor (has brushes). A grinder should be made with an induction motor (no brushes).

(At least that is what I was told when I asked about using one on a drill press!)

[Phil Phelps]

Tom, I prefer the 8" format for grinding tools as it doesn't create so extreme a bevel. While it is true that HHS will sharpen just fine on the 3600 rpm units, the 1725 is a little more forgiving, especially as you are learning to sharpen. So...don't worry about your purchase! It was a super deal for a grinder that will do a great job for you. (I wish I had one of the slower ones for reshaping chisels and other tools that are not HHS...)
Good answer, Jim.

[Alan Tolchinsky]

I just got home from stopping at Woodcraft, on my way home from work, & plopped down $79 (w/tax) for their 8" slow speed grinder with the good wheels - white - I don't know what grit or what kind but they're supposed to be the good ones.

Now I log on and the Old Man says I bought the wrong one :confused:

Oh well It's got to be better than what I'm currently using & you can't beat the price - I think I'll stick with what I bought.


I've had mine for a year and it works great. As said above the slower speed does make it hard to burn your tools. That was a great help to me as a newbie tool sharpener. I think the wheels are 60 and 120 grit. Only thing is sometime I wish one wheel was a little coarser for faster sharpening with less heat build up. But mine works fine. I wouldn't take it back unless it's out of balance or something else. Alan

[Ken Salisbury]

Since there was no real concensus on which was best (1725 or 3450 rpm)

So - - the way to solve this -- -- is to use both the higher speed and the lower speed and judge which method works best for me -- -- so I replaced the 6" Delta VS with a 8" Delta VS yesterday (the base on the 8" does not interfere with the Wolverine bases. Now I can grind at any speed between 1725rpm and 3450rpm.

[Tony Laros]

I bought the Delta 8" VS a few weeks ago. Now I can buy the Wolverine jig 'cause you said it would fit under the wheels. I've been holding off buying it thinking it might not fit.

[Jim Becker]

Mike, the speed control works on a universal motor (has brushes). A grinder should be made with an induction motor (no brushes).

(At least that is what I was told when I asked about using one on a drill press!)

This is correct.

BTW, some folks have retrofitted their DPs with VFD-driven 3-phase motors...the same setup on many of the true-VS lathes today. By shopping surplus, it's often possible to do that without spending a fortune, although it's still not chump-change.