Confused about grinder speed

[Perry Holbrook]

I'm setting up a sharpen station today for turning tools. I followed a thread about sharpening a few weeks ago, and it seemed a lot of you recommended the Wolverine jig with a 2 speed grinder, so that is what I purchased.

In reading the wolverine set-up info, they recommend grinding at 3450RPM and explain why by saying that gives the recommended surface speed of the wheel.

I assumed the 2 speed was recommended in order to grind at 1750. So is Wolverine correct or should I use the slower 1750?

I also need to replace the one 60 grit grey wheel with a white wheel. The white one on the grinder doesn't seem to have a grit number on it. What grit should I buy?

The largest tool I have is 1/2" if that matters.

Thanks, Perry

[Mike Vickery]

I believe the majority of turners use a slow speed grinder. However many do use a high speed grinder and are happy with it. Personally I use a slow speed and a Wolverine system and am happy with it.

Wheel grit is also a personal preference I use an 80 grit but I have heard of everywhere from 60 grit to 120 grit for sharpening.

[Bernie Weishapl]

I am no expert but I have a 60 grit white and 120 grit white wheels. I use the 3450 rpm with my wolverine jig. Actually you can use either speed. I have been told it is what you are comfortable with. You will get both sides. Some like 1725 and the rest like 3450. I have used both. I like 3450 because that is what I was told to use so I started with that speed and it works fine on HSS.

[Jim Becker]

I use a high speed grinder, the Wolverine system and Norton 3x wheels (http://www.hartvilletool.com/product/10846) with the OneWay balancing system. The wheels are in 60 and 100 grit. (I don't prefer 120 grit wheels) Between the quality wheels and the balancing system...my grinder (a no-name "Tradesman") runs like a finely tuned automobile with no chatter and minimal noise.

Oh, and OneWay's recommendation is based on the wheels they and most places sell which are formulated for ~3500 rpm performance. They will work fine at the slower speed, however, if that's what you prefer. One of the reasons that so many folks use a lower speed grinder is that it softens the learning curve relative to "light touch". Once you develop that "touch", you may actually prefer the higher speed.

[Dennis Peacock]

I'll go against the 'grain' here and state that I use and prefer a slow speed grinder. I use a 80 grit and a 100 grit A/O wheel along with a Wolverine type setup. I did use a high speed, but the slow speed allows me a more "relaxed" feel while at the grinder.

[Perry Holbrook]

Thanks. I had a feeling it was personal preference.

Perry

[David Lancaster]

Hi Peter
The One way wheels are matched to the diameter and the speed of the grinder. They are available for slow speed or high speed grinders but they are not interchangeable. The hardness of the wheels and the resin are designed to cut high speed tools at the rpm they are designed for. I use a 3450 Ryobi grinder with the balance kit,it makes a cheap grinder run very smooth.One 54 grit and one 80 grit The wheels will last a long time ,but remember to clean them often with a diamond dresser. If you use the white wheels you may have a false feeling of success because you remove so much metal at each sharpening.

Dave Lancaster

[George Tokarev]

Big discussion as always, as to which is "better," but in point of fact, as we know, you can move the tool over a stationary stone and abrade steel, which is a pretty good reason to say it makes no difference to the quality of edge.

Dave has the essence, I think when he mentions that folks are mistakenly thinking about how much you take away, of stone as well as tool. Hey, if I'm freshening my own hard-earned edge on a stone I had to pay good money for, I'm interested in taking away as little as possible to get by. If you bring twice as much grit past the tool in the same amount of time, you can move some metal. If you have a soft bond stone, you can remove some grit. if you keep dressing the stone to get it flat and fresh, though why that's desirable except when trying to get an edge on a straight tool I don't know, you can remove both.

Main thing is not to press. Builds heat and knocks away grit. I like to sharpen the same as I cut wood, A-B-C, only the C here is the stone cutting the steel. What's real important is circularity and stability of the stone. Vibration or intermittent contact with the stone makes it as tough to freshen an edge as it does to take a good cut at the lathe under the same conditions and for the same reason - loss of tool control. Same solution - get a good anchor and sweep the tool across gently.

[Glenn Hodges]

I will not get into the argument either, but tell you what I use. I don't really think it matters much on high speed steel if you will be careful. I use the Woodcraft slower speed grinder with 100 grit on the left side of the grinder and 60 grit on the right side where I have the Woverine Jig for my gouges. I use this setup because I was taught this method, and it works fine for me.

[David Lancaster]

Peter
My statements were made with your question in mind. Oneway prefers a 3450 grinder with their 3450 wheels. When dressing a wheel it is done with a light touch with the diamond this removes any metal particles on the wheel that will rotate against the edge as you sharpen.This combination of speed and wheel will make your tools and wheel last the longest
Dave Lancaster

[Richard Madison]

Perry,
Makes little or no difference to the rock or the tool. As suggested by Jim and others, the primary advantage of a "low speed" grinder is that it gives you a few extra milliseconds in which to quit screwing up before you screw up even worse. That said, which ever is comfortable for you and gives good results is the right speed.

[Jim Becker]

And now for a minor "station break"...Dave Lancaster...Welcome to SMC! (back to our regular programming... :D)

[Rick Levine]

Slightly off the main subject, I'd like to pass along a bit of information I just learned from one of the techs at Oneway.

I have a Delta 8" variable speed grinder and also purchased the Wolverine balancing system. When I tried to put the wheels on the grinder according to Wolverine's instruction sheet I discovered that the proprietary nuts that lock the wheels on the shaft hit the two balancing nuts and would not seat properly.

I call Oneway and the tech explained the modified procedure to me.

What you have to do is reverse the left and right flanges they supply, add a regular washer (make sure you use one that has a hole the same size as the arbor) first on the arbor then turn the balancing nuts inward. The tech suggested getting a regular washer but I was unable to find one with the correct whole size and, in my case didn't have a 5/8's inch drill bit to re-drill the hole. So I called Oneway and asked them to send me a couple of extra washers they supply with the kit. The washers they supply are machined flat and I felt they would be better for balance even though he said it wouldn't make any difference. I found that I needed two on each side.

I hope this is clear. I seemed a bit confusing at first but after trying it, it made sense.