Grinder for CBN wheel for sharpening

[Pat Barry]

. I suspect someone will "do the math" and give you the actual numbers.

The depth of the hollow is only about a maximum of 1.5 mils (0.0015") difference comparing the 8 inch wheel to the 6 inch wheel.

[Andrey Kharitonkin]

I suspect someone will "do the math" and give you the actual numbers.

Hollow will be deep like this:

deep = R - sqrt( R*R - a*a/4 )

Where "a" is the length of the hollow bevel measured straight between start and end of the hollow grind, thanks to Pythagoras

[Andrey Kharitonkin]

Some useful numbers:

For hollow 1" long the difference between 6" and 8" wheel would be 0.005" (0.021" vs 0.016")

For hollow 1/2" long the difference between 6" and 8" wheel would be 0.0013" (0.00521" vs 0.00391")

So, from theoretical point of view I can conclude that 6 or 8 mostly different in speed of work and life span and money. In practice - I don't have any.

[Frank Martin]

I ended up with a slightly used 7" full speed (3600 rpm) Baldor at a great price. Now onto finding the right CBN wheel. It appears 180 grit is the one to start. I have been thinking of getting a 1.5" wide wheel with side grinding option (i.e., about 1" portion of the side coated in CBN) but have not yet found one.

Any recommendations? This will be used for plane irons and chisels for the most part. I don't do turning and no plans at the moment.

[Derek Cohen]

Frank

Contact Ken Rizza at Woodturners Wonders. He provided super service to me.

Apparently Ken has crowned wheels in now, as well as the straight wheels I use:

http://woodturnerswonders.com/collec...own-cbn-wheels

I have no difficulty with straight wheels since they are wide and grind so fast. However, if you are used to running the blade past a crowned face, then you may prefer the crowned wheel.

Get the 180 grit. I use it 90% of the time. I also have a 80 grit, which is intended for deep grinding.

Regards from Perth

Derek

[Charles Bjorgen]

I also have a 7-inch Baldor although mine is 1800 rpm. The only vendor I found selling 7-inch CBN wheels was D-Way Tools. I don't see any side grinding options in his list but you should contact Dave, the owner, to see what he can offer. I bought the 180 wheel and removed the outer half of the wheel guard and attached a magnet at the back of the inner half to collect metallic particles from grinding. I use my setup primarily for turning tools so it is equipped with the Wolverine system.

I suppose your side grind options might improve if you remove both halves of the wheel guards so you can then install an 8-inch wheel.

[Derek Cohen]

You can use wheels from 6" - 8" on a 7" machine. The guards are not necessary with these wheels.

Regards from Perth

Derek

[Jim Ritter]

I have one of the crowned CBN wheels, there was a bit of a learning curve for me, it is very fast and doesn't heat the tool much at all. The first couple tries ended with a bit of a scalloped edge that I had to true up on stones. Now that I've got the hang of it it is possible to grind cambers without rotating the blade, just by varying the pressure.
jim

[John K Jordan]

I ended up with a slightly used 7" full speed (3600 rpm) Baldor at a great price. Now onto finding the right CBN wheel. It appears 180 grit is the one to start. I have been thinking of getting a 1.5" wide wheel with side grinding option (i.e., about 1" portion of the side coated in CBN) but have not yet found one.Any recommendations? This will be used for plane irons and chisels for the most part. I don't do turning and no plans at the moment.

I can't help with the exact grit (I don't sharpen plane irons much), but I can also say Ken Rizza at Woodturners Wonders has treated me right. I have purchased and ordered 6 wheels from him now for myself and others, from 80 to 600 grit. I do like the 600 grit wheels but that may not matter if you finish your edge on a fine flat stone.
http://woodturnerswonders.com/collections/cbn-wheels


Oh, Ken also sells an inexpensive washer set that can help the wheel run perfectly true on some grinders.

For my sharpening (mostly turning tools) I prefer the flat wheel with the square corners (not radiused) and with the 1" side coating. Can you remove the wheel guards and use the 8" wheels on the 7" grinder? Most people run CBN wheels without the guards.

JKJ

[Frank Martin]

I will contact D-Way and Ken Rizza at Woodturners Wonders to see what they recommend. I prefer 7" wheel to keep the surface speed a little lower compared to 8" wheel as my grinder spins at 3600 rpm.

Thanks!

[Frank Martin]

I realize Ken's wheels are aluminum as opposed to D-Way's steel. Any disadvantage to aluminim wheels? I know they are lighter and can be better for low powered grinders but I don't think this is an advantage in the case of Baldor I have.

[Patrick Chase]

I realize Ken's wheels are aluminum as opposed to D-Way's steel. Any disadvantage to aluminim wheels? I know they are lighter and can be better for low powered grinders but I don't think this is an advantage in the case of Baldor I have.

Ken's square-cornered wheels have aluminum hubs, but the substrate onto which the CBN is electroplated is still steel. His round-cornered wheels are all steel just like D-Way's. I don't think there's much of a practical difference between the two.

[Derek Cohen]

I realize Ken's wheels are aluminum as opposed to D-Way's steel. Any disadvantage to aluminim wheels? I know they are lighter and can be better for low powered grinders but I don't think this is an advantage in the case of Baldor I have.

I have both types and cannot tell the difference. Personally, I would rather deal with Ken, and that makes a difference where I would go shopping. The support service from Woodturners Wonders was fantastic.

Regards from Perth

Derek

[Frank Martin]

Sounds great. I will go ahead with Ken. Thanks for helping me with all the first hand information.

[Jim Ritter]

Another vote for Ken as a great guy to work with. I spoke with him a couple of nights ago and asked about the 3000 limit on the wheels and his reply was the faster speeds increase the risk of heating the tool. I was concerned because my CBN is on a 3600 RPM 6" grinder. Structurally it is not a limit. I've never even heated a tool that was much more than wam to the touch.
Jim