Tuesday, December 29, 2015

More on CBN Wheel

More on the CBN wheel in answer to a couple of questions about yesterday's post.

Here is a overview of the grinding station I have set up in the "tool room" aka Fibber McGee's closet:

The Tormek with a 600 grit CBN wheel is on the right and a low speed grinder (I think from Woodcraft) with a "pink" wheel and a 180 grit CBN wheel on the left. The rest for the pink wheel is from Veritas and the CBN wheel has a Tormek GBM-100 tool rest.

Because you can not dress the CBN wheel to make it co-planer you have to adjust the GBM-100. There is the rub, as Derek Cohen put it getting there "is not for the faint hearted". I got there but....it took a lot of back and forth adjusting the Tormek tool rest then make a test grind, re-adjust the tool rest, make a test grind.....I ending up digging out a paint can opener to make the test grinds. The other problem is the CBN wheel removes metal so fast even when you are co-planer the bevel can end up with scallops if you let the speed of cross movement or pressure vary as you grind. Again all those can be overcome with practice but a CBN wheel on a low or high speed grinder is not a turn-key answer. Depending on how much grinding you do its advantages may be enough to make it worth while but....it ain't plug and go.  

Here is a close up of the grinder with pink and CBN wheels:

The low speed grinder with the Tormek tool rest was good enough when I heard there was a 50mmX250mm CBN wheel made for the Tormek T-7 it was a no brainer, I couldn't get my AmEx out fast enough. While not cheap, I expect I would have toted the note at twice the price.

On the T-7 all the fiddling is taken care of, it is, from what I can tell, plug and play. On the T-7 the rest is built in co-planer, the speed is slow enough, the grit is fine enough and the wheel is wide enough to control the aggressiveness of the CBN wheel. The ground bevel is flat, smooth, and just for Ralph, ninety degrees to the side. Honing the ground bevel was very easy, I did it freehand on oil stones and it was fast, might have been faster on the Shaptons. 

If you already have a Tormek T-7 and the slowness of the grind bothers you you owe it to yourself to make the change, if you don't have one it might make it worth while to buy one.  I have to admit the T-7 may have been headed for Craig's List if not for the CBN wheel even with all the advantages of the T-7 if it is only used for grinding, the slowness of grind using the water cooled 220 grit Tormek stone was hard to overcome. The CBN wheel is a game changer.


  1. Interesting, thanks for answering our questions Ken.
    That CBN wheel on the lo speed grinder seems to produce a heck of a lot of "residues stuff" for lack of a better word. Is that from the wheel itself or the tool??

  2. Bob,

    From the tool. I did at least the equivalent of 6 months grinding getting the tool rest parallel. Off the wheel I expect there will be little to no waste.


  3. Ken,
    does the tormek angle setting gauge work on the CBN wheel. I can't see why it shouldn't?
    The tormek does a very good job of squaring tools albeit slowly. I may look into getting a CBN wheel now. Is the 600 grit aggressive enough to remove nicks etc and re-establish an edge?

  4. Ralph,

    Yes, in use the CBN wheel is no different than the Tormek wet wheel other than you can run it dry.

    I would not want it to be any more aggressive, The 180 grit on the 8" grinder is too aggressive for easy control. The 600 grit is a nice balance.

    The wheel isn't cheap but it isn't a lot more expensive than a Tormek replacement wheel maybe less IIRC. The biggest advantage is it will keep me from selling the Tormek and going back to a grinder for my grinding. A Tormek is a better way if it were not so slow as it is with the wet wheel.

    BTW, I just looked at Tormek replacement wheels. The CBN is cheaper than the Japanese wheel and $35 USD more than the black wheel which was going to be the next step before giving up on the Tormek.


  5. Ken - I have a Tormek and really want one of these CBN wheels but I like that the wet wheel grinding cuts down on airborne metal dust. Have you tried running the CBN wheel with water in the tub?


  6. Mike,

    Sorry to take so long to reply but we were in Houston visiting the grandpeanut on his 1st B-Day.

    Yes I run the wheel in the water trough. It seems to keep down both the dust and keeps the wheel from loading. No noticeable problems so far.