Grinder choices, grinder speed

[Aaron Wingert]

I'm wanting to replace my Delta 8" variable speed grinder that I use for sharpening my tools (with a Wolverine system). Very long story short, the grinder is out of warranty and ever since I took the original wheels off to replace them with Norton wheels, they will not run without wobbling. It is a left/right wobble as you face the grinder, not an out-of-round issue. I can of course true the wheels for round, so that isn't the problem. I've machined good acetyl bushings to rule out the cheesy nested bushings that Norton includes with their wheels as the problem. I've taken it to the Delta service center, who recognized the problem but couldn't help since it was out of warranty and they didn't see it as something that could be corrected after looking at it for quite a while. They tried Delta wheels on it, which didn't correct it. It is usable, but certainly not smooth, and it irritates me to no end.

So, I am ready to replace it with a better quality grinder, in hopes that I'll have better luck.

Looking at options, I'm finding that not many folks make a variable speed grinder or slow speed grinder. Delta and Woodcraft's model seem to be the only choices, and I looked over the Woodcraft one pretty close and just was not impressed at all. Its quality seems to be on par with the Delta I have, and a lot of reviews I've read indicate that people have had trouble getting wheels to run true on it. I'm leaning towards the Jet 8" grinder, but it runs pretty quick RPM's. I'm a pretty firm believer that HSS tools do not have their temper ruined by heat from grinding, based on my experience and reading. But I recognize that you're bound to take more steel off your tools when the wheel's moving that fast.

Looking to you guys for your input. What grinder do you have, and has it served you well? Have you changed the wheels on it, and when you did, did you have problems with left/right wobble? Those of you that run regular-speed grinders, has it worked ok for your sharpening?

I'd go for a Baldor, but can't swing $500 for a grinder. If I could, I'd be looking into a Tormek. I just love the Wolverine setup and don't want to give that up.

Thanks for any input you might have!

Aaron

[David E Keller]

I'd keep your old grinder and buy a CBN wheel... Unless the shaft is bent, it'll run true, and it's the nicest wheel I've ever used. I've got the WC grinder, and I've had no issues.

[Joe Bradshaw]

AAron, If you have not already done so, remove both wheels and run your grinder and check for runout on the shafts. Take your metal washers(can't remember what they are really called, CRS you know)and rub them on a piece of sandpaper on a flat surface. This will give you a flat surface to place against the wheels. McMaster-Carr sells drill bushings that you can get to fit the hole in your wheels and the shafts of your grinder. While you are doing this, go ahead and replace the bearings. It is a simple job. Now, after you have done all this, go ahead and buy the CBN wheels as has already been suggested. It is a shame really to put almost $400 worth of wheels on a $100 grinder, but you will be really pleased with the results.

[Jim Burr]

I'd skip all that and get the Grizzly wet sharpening Tormek clone...The wheel is gradable from 220 to 1000 and all the Tormek stuff, save one that wasn't turning related, fit the Griz. Just MHO.

[Charles Bjorgen]

For the record, Aaron, Oneway recommends standard 3450 rpm grinders with their Wolverine system. Having said that, I bought a Baldor 1725 rpm 7-inch grinder about 10 years ago. Can't recall exactly what I paid at the time but it was probably around $325 or so. I run it with conventional aluminum oxide wheels. If the wheels seem a bit out of round, I run several pencil lines on the wheels and true them up with light touches with a T-shaped diamond dresser. Never felt the need for a balancing system. After turning off the motor, it seems to take forever for the wheels to stop turning which to me is an indication of how smooth running the Baldor is. I sharpen with both the Wolverine system and the Elsworth jig for a couple bowl gouges.

[Jamie Donaldson]

Aaron- the wheel flanges on Woodcraft grinders, as well as some other brands, are the usual culprit causing wobble. I have trued up many grinder/wheel combinations by first marking an index spot on a wheel, loosen the nuts to allow the wheel to be hand rotated, then move wheel about an inch and again hand rotate the wheel to see if the wobble is better or worse. Of course if the shaft is not running true all is for naught, but a well tuned wheel is a necessity regardless of the motor and fittings. And I do love my slow speed Baldors, but bought the big one "only slightly" used, and would never have a faster or variable speed motor.

[Clint Baxter]

Aaron, I have the Jet 8" grinder and am happy with it. The RPMs are up there but if you keep a light touch, it works well. The wheel flanges on mine led to some wheel wobble until I changed to the Oneway balancing system. I am, however, seriously considering putting on a CBN wheel due to all the rave reviews on their performance. Good luck on whichever way you go.

Clint

[Bernie Weishapl]

I use a 1725 rpm grinder and like it a lot better than the 3450 rpm that I started with. I am considering the CBN wheels but haven't because of the price. I do have a Tormek that I use for most of my sharpening and use the grinder to shape tools.

[Reed Gray]

You can buy the two D Way Tools CBN wheels for what a good quality grinder would cost, about $360 or so. You will never need to balance them. You will never need to true them up. You will never need to clean them. They will never break apart. They will never change size. They are also 1 1/2 inches wide. They will come with high quality metal bushings. You will get more than your money's worth out of them as they will outlast by several times what the comparable cost would be to use standard or the fancy Norton wheels would run you.

robo hippy

[Josh Bowman]

I'd keep your old grinder and buy a CBN wheel... Unless the shaft is bent, it'll run true, and it's the nicest wheel I've ever used. I've got the WC grinder, and I've had no issues.
+1 on what David said. Bet the problem is not the grinder, but the wheels. For all the wobbly wheels I've bought, I could have easily bought a CBN and came out ahead.

[Aaron Wingert]

Thanks for the insight guys. I haven't seen or heard of these CBN wheels, so I'll definitely give those a look. I'd feel a lot more comfy spending that much on a wheel if I had any faith that the grinder was perfect, but I'm just not confident of that. So maybe a new grinder with a new CBN wheel is in order!

Sources for CBN wheels?

[Aaron Wingert]

Well, I've ruled out the wheels as the problem 100%. The wobble is very evident in the cup washer that seats on the arbor on the motor side of the wheel. I used a metal bushing about 1" diameter in the wheel's place to compress the cup washer to the shaft and tightened everything down. When fully seated it has about 1/32" of wobble left to right.

I'm going to relegate this grinder to sharpening lawnmower blades and buy myself a new one. (and hope for better results)

[Alan Trout]

Aaron,

Listen to Reed, and David. The CBN wheel will cure your problem. You will not have to buy a new grinder. It does not use the cup washer like a standard wheel. Here is a link to D Way tools that sells them. http://www.d-waytools.com/tools-diamond-grinding-wheels.html

Good Luck

Alan

[Aaron Wingert]

Thanks for the link Alan. The videos on that site are quite convincing, and they've seemingly worked around the darn cup washers that are making using this grinder such a challenge for me. I'm going to be ordering a 180 grit 1-1/2" wheel on monday! Never seen those before, and they're certainly amazing.

[Alan Trout]

Aaron sounds great. Its better than dealing with an other grinder.

Alan

[Aaron Wingert]

I just wish I could afford two of the CBN's.

The idea of having a 1-1/2" width to grind on is nice too....Beats a 1" wheel all day long.

[Ryan Baker]

Aaron, you have correctly determined that the problem is the cup washers ... or more specifically the way they [fail to] seat against the tiny shoulder on the shaft. You will never get those to sit square. The only way to make that grinder useable is to go to a solution that doesn't use the cup washers. In my case, I used a Oneway balancing kit -- the hubs fit nicely on the shafts. (I also got rid of the stupid speed nuts at the same time.) The CBN wheels should solve the problem the same way, though I have not tried them personally. Note that if you only replace the wheel on one side, there will be a certain amount of vibration transmitted over from the wheel on the other side. You will probably want to apply some fix to the other side as soon as possible. Another partial solution -- if you can find/make/have made a machined washer to replace the cup washer (with the center hole machined precisely enough to seat square on the shaft step), that will make a big improvement in the wheel balance.

[Aaron Wingert]

My CBN wheel's ordered (1-1/2" wide 180 grit). You guys sure do have a talent for sucking money out of my wallet and getting it in the hands of folks that make cool tools and tool-related accessories. In all seriousness, thank you all for your help with this. Spoke with Dave at D-Way tools at length and he's definitely a good guy and I can't wait to try that wheel when it comes.

Now focusing my attention on getting the Norton wheel to run smooth on the opposite side of the grinder. Ryan, I'm liking your idea of going with a machined washer instead of the stamped cup washer, which is something I've been considering pretty hard since I started messing with this problem. When I get home tonight I'm going to see if the machined flat washer that goes on the outside of the wheels would work for this on the inside....I don't have high expectations for that, but it sure would be nice if they would, because with the addition of the CBN wheel I'll now have a spare washer. Going to see what I can come up with, but may end up going with Oneway's wheel balancing setup. With the addition of the CBN wheel on one side, it would be a shame to have the Norton wheel on the other side wobbling like crazy.

[Reed Gray]

In a really bad case, you take both wheels off, and run the motor to see how much run out there is. Then, mount one wheel, and true it up. If you have a platform, you can use a dresser, and ease it into the wheel, gently nibbling off the high spots and wide spots, till it runs fairly true. Mark wheel, washer, and shaft orientation so you can put it back on exactly the same way. Then take that wheel off, and do the other side. then put them both back on, and fine tune them together. Once done, they should be fine, with minor tune ups.

Or, you could buy a Baldor grinder.

robo hippy

[Ryan Baker]

Oneway has machined washers -- there is usually one in with the balancing kit. If you contact Oneway, they might sell you a couple washers for some nominal charge.

[Aaron Wingert]

The CBN is just plain amazing. AMAZING. Thanks guys.

I'm probably going to get the Oneway balancing kit for my Norton wheel to get it running better. Hopefully with a machined washer and all.

[Bill Neddow]

I did a tremendous amount of research on grinder wheels for an article I wrote for the AAW magazine -- an I agree totally with Reed.

[Aaron Wingert]

Just a little update on this quest:

Still getting a small amount of vibration even with the CBN wheel running true and the 3X wheel removed. I removed the large hinged nuts that hold the wheels on the arbors on, because I wanted to rule them out as being out of balance. I got myself a left hand 5/8-11 nut and put it on there. It really smoothed the grinder up in a hurry. So those hinged nuts were definitely out of balance.

My OneWay wheel balancing system is on the way as well, in hopes of getting the 3X wheel running true.

[Aaron Wingert]

A final update:

The Oneway balancing system on my 3X wheel worked slick. It took about 90% of the wobble out of the wheel and it took 100% of the vibration out of the grinder. It has maybe 1/32" of wobble left, but nothing I can't live with. The grinder runs as smooth as silk now. Thanks for all the help guys, it is genuinely appreciated.

Aaron

[David Hostetler]

Aaron, your problem isn't the grinder, but rather the wheels / bushings that go with those Norton wheels... I had the same trouble. I used some steel machine bushings instead of the stack of cheap plastic sloppy junk that Norton ships, and then trued up the wheel using Don Geigers "Geigers Dressing and Truing Solution" I think it was called... I now have negligible side to side runout (.001") and if I had to guess from the quality of things, that has to be in the wheel itself, not the grinder. Don's solution tool thingamabob isn't cheap, but is sure worked well! Maybe your wheels are round. Mine had a bump in it... No need for the Oneway system... I am running smooth as silk with a full speed Ryobi 8" grinder now... Couldn't be happier. And trust me, the issue isn't that the Ryobi is all that great. Again, it's the incredibly poor quality control with Norton...

[Ryan Baker]

Aaron, your problem isn't the grinder, but rather the wheels / bushings that go with those Norton wheels...

Nope, not true. I agree that the bushings are a problem, and replacing the bushings will work on many grinders (when combined with a good wheel dresser). However, for this particular grinder (and some others), the grinder itself is a very big part of the problem that can't be solved just with bushings. Plenty of us have tried and proved that. It just depends on the situation.

Glad to see you got it working, Aaron.