Grinding Wheel Questions

[Nick Mastropietro]

I know most folks here perfer 8" grinders but I have an almost new 6" veriable speed grinder so I'm going to stick with it for now. Again many think the Norton 3X Blue wheels are great. As I have researched these wheels I have only found them in 46 and 80 grit in the K-grade for 6"x3/4". What 2 wheels would you recommend, these 2 or some other combination/grade?

[Allen Neighbors]

Nick, I have no idea which to recommend for you. I have an 80 grit and a 120 grit wheel, but I don't have a clue which grade they are. My 80 grit is gray, and the 120 grit is white.
As you know the curvature of the wheel puts a hollow grind on the bevels; a 6" curve will put more of a hollow grind on than the 8". If you start having trouble with the bevel causing a 'bruise' line inside a bowl, it may help to add a secondary bevel by grinding the heel of the bevel. Just some information that may help you sometime.
As far as it being a 6" wheel - I'll bet it'll work just as well. Hope you can find the wheels you want on there.

[Bernie Weishapl]

I use the wheels that came with my woodcraft grinder. 80 and 120 grit. Don't see a need to change them out as they work just fine.

[Gordon Seto]

Yes, the Norton 3X K only comes in 46 & 80 grits. They run cooler, do not need to be dressed as frequent and hold up well. They are almost as good as the Norton SG wheels that cost 3 times more. IMO, they are a big step up from the OEM wheels from the WC slow speed grinder.
Don't get the I; they don't hold up with turning tools.

[RL Johnson]

Gordon has it right, I replaced one of my WC white wheels with the Norton 3X wheel and the difference is like day and night on sharpening my tools. For the price it sure is hard to beat the 3X wheel and it was money well spent.

[Vince Welch]

Nick,

Another option might be to look at the Oneway wheels which come in 6". I have two 8" Oneway wheels along with the balancer system on the WC grinder and there is no vibration and the difference is 180 from the wheels that were on the grinder.
Vince

[Don Geiger]

Dear Fellow woodturners:

If you took two identical tools and sharpened one on a 6" wheel and sharpened the other on an 8" wheel at identical angles, due to the difference in the radiuses of the wheels and the amount of hollow grind produced, the point where the bevel meets the cutting edge will be more accute on the tool ground on the 6" wheel. The problem with this is because it is more accute, the edge will wear more quickly, the tool will be more aggresive and it will vibrate more on the wood.

I have a graphic from one of my Power Point presentations that I can post at a later date. Unfortunately, I don't have it with me.

As far as wheels are concerned, the very best, most-effective improvement you make to any wheel is to make it truly concentric to the axle of the grinder. This will significantly reduce grinder vibration, tool bounce and will improve the bevel and edge of your tools. It also eliminates the need to balance your wheels. Do an Internet search for: "Geiger's Wheel Truing and Dressing Solution" if you want to learn more.

Don Geiger

[Nick Mastropietro]

Don is it possible to correct for the more accute edge by changing the grinding angle?, and if so, what might be the best angle? Are there other acceptable solutions besides buying a new 8" grinder?

[scott schmidt grasshopper]

hi nick I am also one of the few with a 6 inch vs grinder. mine was the cheapy inventory closeout type from delta. here is why I love mine.
1 its slower speed than the 8 inch at any given speed the 6 inch is about 30% slower on the face of the wheel than the 8 inch due to circumferance (sp) slower is better they say . I bought some of the fragable white wheels think I have the norton 60 and 100, I use the 60 for bowl gouges and scrapers and the 100 for the skews and spindle gouges and get a good edge off them . the 6 inch fit inside my "space" much better than the 8 inch would have, as for complaints of angles etcI cant say I notice any differance I sharpen often enough I cant say the grinder is at fault or was it the tool metaltype or the hard wood I am running? I did have to balance my grinder wheels but did that with use of my wheel dresser. the one thing I had to work out was drop to use my elseworth bowl jig. I had the raise the grinder to get the drop needed for the arm other than that wheel wear has been almost undecernable after 3 yrs good luck scott

[Don Geiger]

You could go to up to a 55 degree angle which would make the edge less accute, but realize that the more you move in that direction means you will increase the number of situations where you won't be able to maintain bevel contact when removing material from inside of a bowl. Gouges greater than 60 degrees (up to 85 degrees) are used for this purpose.

Use the 6" grinder until you have the resources to buy another. As you wear the diameter of any wheel down, the effect I mentioned earlier increases. I recommend changing 8" wheels when they get to 7" and 6" wheel when they get to 5.5".

If you eventually decdide to get a new grinder, I suggest an 8", 1800 RPM grinder with 1" wide aluminum oxide wheels in H, I, J, K or L hardness. This suites the need of a large majority of turners.


Sincerely,
Don Geiger


Don is it possible to correct for the more accute edge by changing the grinding angle?, and if so, what might be the best angle? Are there other acceptable solutions besides buying a new 8" grinder?