I promised a write-up on these wheels. They aren't broken in yet so I will post a follow-up in this thread eventually but I don't think things will change much.
The inch and a half wide 350 wheel is the one I use for my gouges so it has seen the most use. In a word or three, absolutely perfect for me! Being stingy with metal I am usually trying to avoid overgrinding even with my white 100 grit stone wheel. The 350 grit allows me to use gentle pressure with better control. Do have to watch the edge melting away, no sparks to tell when you have cut to the edge of the bevel. My white wheel always feels a little grabby and the tool wants to walk around on the wheel. No issue with that with this wheel, the tool is super easy to control. The metal is ground away of course but seems to be just melting.
There is a big difference between a stone that is wearing away under the steel and one that isn't. The worst thing about these wheels, it took me a long time to get things perfect during set-up. My 8" stone might have been smaller than I realized as part of the issue but getting the scuff mark in the center of my bevel top to bottom was a pain. In the end I was moving the arm of my Wolverine sharpening rig in and out the tiniest fractions of an inch, maybe a sixty-fourth or less. If you draw an arc and then draw a slightly larger radius arc inside the original arc you can see the issue easily. Would have been a lot easier to have just reset my angles and ground.
When I cut the entire bevel wing tip to wing tip the first time I found my nice looking bevel from my stone wasn't as nice as I thought looking at the old bevel still showing in places. The reshaping was minor and slight reshaping is quite possible even with 350 grit. A handful of passes due to that frugal with metal thing of mine and the edge of the gouge was shaped better than it has ever been. I had a surprisingly large burr to knock off this first time but minimal after that.
The gouge handles better than it ever has. The shape is better plus it is sharp! All of the theory about the sharper edge dulling faster may be true but real world the tool stayed working sharp much longer than it ever has. I'm willing to sharpen when the tool is still sharp now too, when the tool dulled more rapidly I was more reluctant to take time to sharpen. This was plain old M-2 steel, a Crown tool. My first real turning tool and still the most used. I use it for roughing my blanks with bark and the things I don't want to use my finer tools for and it often stays in my hands once I start using it.
Once sharpened with the CBN wheel resharpening the gouge is very fast. Set the length the gouge sticks out of the jig, a quick sweep right, a quick sweep left, and done. Shiny new metal top to bottom of the bevel.
This wheel is a keeper. No question if I were ever to wear it out I would have to buy another. No going back to stone after using this.
The 220 grit "4 in 1" wheel has seen a lot less use but I had to try it. I sharpened a skew on the side of the wheel, something that is totally safe with the CBN wheels, or to be more accurate, no danger of explosion as can happen with a stone wheel. For some reason I'm not sure of the different sweep of the grit across the face of the skew makes this put a mirror finish on the skew. Cuts very well and I can't tell the difference in surface when I come behind with my extra fine hone. Not sure what extra fine in the hone translates to, I think 600.
One big plus, using the lamp on my bench grinder always left one side of my white wheel in the shadow. With the guard removed to use the 350 grit wheel that is an inch and a half wide counting 1/4" bevels both sides, I can light the entire surface of the wheel. An unexpected benefit. Speaking of lights and unexpected benefits, Ken threw in a 30 LED work lamp with magnetic base and on/off switch. He sells the same one for twenty bucks.
I have had a hard time parting with $300 for a pair of CBN wheels. It is a pretty big purchase for advantage I wasn't sure of. I have most of the badly needed toys now and an unexpected sale had some cash in my pocket so I have been buying toys. Should have bought the wheels sooner, especially the 350 grit for my bowl gouges since that is what I will use most often.
A utility grinder is still needed around the shop because the CBN will load up badly cutting soft materials including steels. The CBN wheels will clean but better to just not have to. I have a few cheap grinders so this is no issue.
I did get the spherical washers to make installation of the wheels easier. When the wheels don't wear it is much more important to get them true to begin with. Can't true the face by wear or dressing the wheel. The heavier balanced wheels do take a long time to stop. With my little cheap grinder it takes over five minutes for them to wind down from full speed of my variable speed grinder. Can't read the spec plate on the grinder without moving it which I have been too lazy to do. Being able to spin a pair of the CBN wheels was a concern but turned out to not be an issue.
Happy with my purchase. Woodturners Wonders, Ken Rizza, was outstanding to deal with and shipped in a very timely manner. As mentioned elsewhere, the boxes and padding these wheels are shipped in would survive a plane crash too.
Hard to write a balanced review. The only "cons" are the time needed to set the wheels up and the price. The better stones cost very close to the same price so can't even bellyache much about that. The little light works really well too, I expected just a trinket as a free gift.
If you are going to drag out a dial indicator when you set up the wheels be prepared to need some patience. I put the wheels on at the end of the day when my back was hurting already. By the time the wheels were on the back was in full scream, one thing that made the install seem like a long time. However on my grinder where I had to mix and match things over and over to get things to run to suit me I would say I spent several hours on the install. My total runout is .002 or less on either wheel, had to rob the stuff from the "4 in 1" wheel to true the other side so the "4 in 1" wheel that had a thousandths runout now has a little more. I'll true it again later. I can't tell it needs it grinding but my indicator says it does and I can't live with that forever!