Grinder for CBN wheel for sharpening

[Andrey Kharitonkin]

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

That is interesting because normally grinders are fixed speed. In US with 60Hz mains that would be slightly less than 3600 for regular speed or 1800 rpm for half speed. In other countries with 50 Hz mains that would be 3000 or 1500 rpm. Does it mean that with 50 Hz mains regular speed grinder will be fine but with 60 Hz it would be too high? Given the feel of approximation in the answer from Ken (as I understand it) it means that 3000 rpm max means use half speed grinder, with both 50 or 60 Hz mains. Is that so?

[Mike Holbrook]

I will toss another vote in for Ken, who is practically a neighbor. I think he may do custom wheels and does not list everything on line, if you do not see what you want I would call and ask. I believe he experiments with different metal compositions, but does not sell what he has not personally tested thoroughly.

[Jim Ritter]

I think you are overthinking this Andrey. What I understood from Ken was at 3600 RPM it is possible to overheat the tool, at 1800 RPM it is very difficult to overheat. It's not that you can in one and not on the other. My first try with the CBN was a badly ground and chipped chisel from a yard sale. It trued the edge up very fast and bearly got the tool warm. I checked often because I was new to the wheel. He does recommend the 6" wheel for the higher speed grinders (and that is what I have with a radius face) as the smaller wheel relates to less feet per minute of the face of the wheel. So I wouldn't put an 8" wheel on a high speed grinder as the opportunity to overheat the tool goes up.
Jim


edit,
you are right Mike. He will make a wheel with any grit level you want if he doesn't stock it. There will be a wait time for it but he will do it. In fact I asked him to make me a flat honing plate with 300 / 1200 grit combo , it's on it's way to me now. I'm thinking of offering a package deal with the sharpening jig once I get that up and running.

[Stewie Simpson]

This article was of good value to a non electrical background; How to Determine Speed for an Ac Induction Motor http://www.achrnews.com/articles/849...nduction-motor

[Adam Herman]

Anyone use the variable speed delta 8 in? seems like a great price. this would solve your rpm problems at a lower cost. http://www.cpooutlets.com/delta-23-1...bench-grinders

[John K Jordan]

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.

Patrick,

This might be old information.

Ken Rizza told me just now that his CBN wheels are all 6061 aluminum. A few years ago he did have a steel wheel and could have gone with a rounded wheel with a steel rim on a plastic hub, but doesn't carry either of those.

I have 5 of his wheels, 8" and 10", most with square corners and a couple with radius corners. I checked and they are made entirely of aluminum.

BTW, Ken is extremely reachable by phone and email and always seems happy to answer questions!
(678) 442-9454
http://woodturnerswonders.com/

Disclaimer: I have no pony in this race, just a satisfied customer.

JKJ

[John K Jordan]

Anyone use the variable speed delta 8 in? seems like a great price. this would solve your rpm problems at a lower cost. http://www.cpooutlets.com/delta-23-1...bench-grinders

Adam, I don't have one of these but the variable speed looked interesting. I did ask Ken Rizza (Woodturners Wonders) if he had any experience with the Delta. He said several of his CBN wheel customers reported problems with these grinders running true. He did mention that his special alignment washers apparently took care of the problem.

BTW, I use these washers with every CBN wheel. http://woodturnerswonders.com/collec...al-washer-sets

JKJ

[Mike Holbrook]

Reviving this thread as much discussion of Grinders for CBN wheels has been covered in this thread.

I talked to Ken Rizza at Woodturners Wonders (WW) yesterday. He now sells Rikon grinders. He removes the guards and tests them with one or two of his wheels installed. I am considering putting lighter buffing wheel(s) or a single CBN & buffer on my Delta grinder and buying the 1HP Rikon.

I have some issues with the tool rests I have been using, having to do with how one is mounted and the lack of a solid/functional locking system on the other. I am thinking about ordering the new version of the Tormek jig for sharpening cambers on plane blades. Ken Hatch mentions it in a thread below. I would mount it on a BGM 100 tool bar, like Derek Cohen uses on his grinder. Mounting the BGM 100 and the round Stuart Batty rest I have is going to require a little trial and error/experimentation to get them mounted solidly over the wheels. I would like to be able to “grind” a larger variety of the hand tools I use. I am working on a plan for a better sharpening station, using an existing cabinet I have. I would like to get it set up properly the first time, this time.

I plan to end up with a WW-80 grit, Mega CBN with a Stuart Batty rest and a 4 in 1 WW-CBN 350 with the BGM 100 rest on the other side. Unless someone offers other suggestions. I have a D Way 180 grit CBN wheel. I hope the 80 will allow me to grind profiles faster. Although the WW-CBN 350 may be lighter than the D Way, which may make it more suitable for the Delta grinder? The D Way might also just be a backup for the 1 HP Rikon. Ken apparently has a 80 and 350 on his machine.

[John K Jordan]

I have some issues with the tool rests I have been using, having to do with how one is mounted and the lack of a solid/functional locking system on the other. I am thinking about ordering the new version of the Tormek jig for sharpening cambers on plane blades.

Mike,

FWIW, I have been using the Tormek jigs with a bench grinder for a long time, before they offered the kit. I ordered the pieces as spare parts and made a mount from wood. I have things positioned so I can use either the Tormek tool bar or the Wolverine base and accessories - the cutout in the wood block is to allow room for the Wolverine locking handle . I prefer the Wolverine platform for many tools but the Tormek gouge jig for my spindle gouges.

tormek_B.jpg

BTW, I don't use the radiused CBN wheel any more. I far prefer wheels with the square corners (plus 1" of grit down the flat sides). That grinder now has 600 grit and 220 grit CBN wheels.

JKJ

[roger wiegand]

just noticed I was entering the middle of an old thread-- sorry!

I got the 1 hp Rikon and a 180 grit CBN wheel from Wood Turner's Wonders last month, and I could't be happier. It removes metal plenty fast for my taste and leaves a nice edge. The grinder is as smooth as can be. My 1960's sears 6" model has officially been retired to lawn mower blade duty. I'm thinking about a second 180 grit wheel so that I can leave one side set up for the bowl gouge and have the platform support on the other side.

[John Fenn]

I am wonder if anyone has experience with Toycen Tradesman Variable Speed DC grinder with Cuttmasters CBN wheels? I have been eyeing one for quite awhile but there is not much information on them and they are on the top end price wise.

[Mike Holbrook]

John K,
Thanks for the reply. I need more room for larger tools below the rests pictured. I was thinking about mounting a BGM 100 and the SB rest higher, closer to the top of the wheel, which may increase my access to the wheel. The LV rest is not working for me. I think the 1 HP Rikon, being larger, will make more room too.

I guess you are using Ken’s Mega Square wheels now? I believe they come in 80 grit, or have Ken’s selections changed?

Rodger, thanks for your review of Ken’s current offerings.

John I suspect the grinder you mention is not in my current budget.

griner_lq7tilzu.jpg

[John K Jordan]

John K,
Thanks for the reply. I need more room for larger tools below the rests pictured. I was thinking about mounting a BGM 100 and the SB rest higher, closer to the top of the wheel, which may increase my access to the wheel. The LV rest is not working for me. I think the 1 HP Rikon, being larger, will make more room too.

griner_lq7tilzu.jpg

I rotated the photo for you. I don't know why you had trouble - I used Photoshop to rotate and convert it to a JPG.

I'm not sure you'll get that much more useful space to work with. I have 1/2hp, 3/4hp, and 1/hp grinders and there is very little difference between the heights of the shafts. In fact, the grinder you show appears to have a fairly tall base with the controls and they look higher to start with, but perhaps the photo makes it look that way.

I'm not sure exactly what you mean about mounting the rests closer to the top of the wheel. What I'm imagining might make the grinder difficult to use. Is there some way to make removable bases for each of the tool rests, each one indexed to the exact position needed with pins or something, and locked down? I'm imagining aluminum plates with lever-cam clamps or something locking them into place.

JKJ

[Mike Holbrook]

Thanks for fixing the picture John. I tried removing the picture and re loading it, taking another picture....everything resulted in the same upside down picture. The pictures I took were right side up before I loaded them into SMC. I even tried using a program, like Photoshop, to turn the picture upside down, thinking it might end up right side up....not. My best guess is there is some sort of gyroscope bug in the new iPad/iPhone system 11 IOS software. It will take a while to get all the bugs out of the major software changes in system 11. I think I have seen others having similar issues.

Large objects, like large axe heads, do not fit on the SB or LV rests because there is not enough space below the rest to fit the rear end of the tool in. A flatter rest, at the upper part of the wheel, orients the back end of the tool further from the table top. I am tryng to lay the axe head on the rest’s table so I can maintain the same angle to the wheel.

Do you have issues with 1/2 HP grinders wearing or slowing down, due to lack of HP? The other issue I have with the Delta grinder is the axel is too short for some CBN wheels.

[Clint Bach]

Your grinder seems to be pretty far back on the table. Moving it closer to the front edge might solve your problem. Better access and tools not interfering with the table. Just saying...

clint