Grinding wheels for bench grinder?

[Rickoo]

Thinking of replacing mine and am wondering if anyone has a recommendation for grit size and/or manufacturer names? I would assume both course and finer grits? I have a 7 inch Metabo bench grinder. The wheels aren't in that bad shape, however I'm getting noticeable wobble at lower rpm and am wondering if these wheels aren't true. (Is this typical with bench grinders? This wobble has been present since I purchased the grinder maybe 5 years ago.) I would expect the wheels to run truer and thought I would check a set of new ones. The grinder appears fairly well constructed. I've checked runout on the shafts and get about 1.5 - 2 thousandths on each shaft. Not sure, but that doesn't seem like it would cause the wobble I'm seeing.

Recently started messing with my rebuilt South Bend 9 and want to begin learning the process of sharpening HSS lathe bits.

Thanks!

 

[WobblyHand]

Thinking of replacing mine and am wondering if anyone has a recommendation for grit size and/or manufacturer names? I would assume both course and finer grits? I have a 7 inch Metabo bench grinder. The wheels aren't in that bad shape, however I'm getting noticeable wobble at lower rpm and am wondering if these wheels aren't true. (Is this typical with bench grinders? This wobble has been present since I purchased the grinder maybe 5 years ago.) I would expect the wheels to run truer and thought I would check a set of new ones. The grinder appears fairly well constructed. I've checked runout on the shafts and get about 1.5 - 2 thousandths on each shaft. Not sure, but that doesn't seem like it would cause the wobble I'm seeing.

Recently started messing with my rebuilt South Bend 9 and want to begin learning the process of sharpening HSS lathe bits.

Thanks!

Probably need to dress the grinding wheels. This is typically done with a diamond dresser, or a steel dresser wheel. Just dress the business end. Pretty common for wheels to not be well balanced.

The shaft should run truer than 0.002".

 

[Rickoo]

How would dressing the face of the wheels help? The wobble is visible side to side.

What grit wheels would you think best for grinding lathe bits?

 

[Batmanacw]

This is what I just bought for hss. Norton says it's good for that. I only sharpened a drill bit so far and it did fine. Might still be a bit hard.

Norton Grinding Wheel - 6in. x 1in White Aluminum Oxide, 60 Grit 76607882615 | eBay

The Norton Premium White Aluminum Oxide Grinding Wheel is a better choice for all general-purpose bench and pedestal grinder applications. Premium white aluminum oxide wheel is ideal for light metal removal and sharpening of high-speed tool steels 55 RC and higher. Abrasive Type White aluminum...

www.ebay.com

 

[WobblyHand]

How would dressing the face of the wheels help? The wobble is visible side to side.

What grit wheels would you think best for grinding lathe bits?

If you have wobble side to side of the wheel, it could be the runout of the shaft is translating into wobble. Or the washers that clamp the wheel are not true to the shaft. If there is a flange on the shaft, check it for axial movement. Make sure there's no oil, grit or foreign matter on it.

I had to machine bushings for my carbide grinder to reduce the side to side wobble. Made the flanged bushing with an almost interference fit to the shaft. When I measured the original bushings they were a few thousandths side to side near the shaft. For me, making new bushings fixed the problem. The shaft itself was true.

If you have a couple of thousandths of axial wobble at only 1/2 inch away (radially), then at 3.5 inches away the wobble at the edge of the wheel will be 7x greater (0.014"). 3.5/0.5 = 7. This is just an example.

I'm using a white wheel (alumina) at 80 grit in my grinder. 60 grit is fine too.

 

[Rickoo]

If you have wobble side to side of the wheel, it could be the runout of the shaft is translating into wobble. Or the washers that clamp the wheel are not true to the shaft. If there is a flange on the shaft, check it for axial movement. Make sure there's no oil, grit or foreign matter on it.

Everything is super clean. Metabo (at least the one I have) uses a flanged bushing setup that fits the shaft and wheel extremely well. This unit may not be true or square however.

I had to machine bushings for my carbide grinder to reduce the side to side wobble. Made the flanged bushing with an almost interference fit to the shaft. When I measured the original bushings they were a few thousandths side to side near the shaft. For me, making new bushings fixed the problem. The shaft itself was true.

If you have a couple of thousandths of axial wobble at only 1/2 inch away (radially), then at 3.5 inches away the wobble at the edge of the wheel will be 7x greater.

(0.014"). 3.5/0.5 = 7. This is just an example.

I'm using a white wheel (alumina) at 80 grit in my grinder. 60 grit is fine too.

Was thinking that trying another wheel (of good quality) and, if the wobble remained, that would remove the wheel from the equation.

Thanks.

 

[mmcmdl]

Norton 32-A 46 or 60 is my go to wheel .

 

[WobblyHand]

Measure the flange. If it's not true, there is a large contributor to the problem. Not saying your grinding wheel is good. But, measure what you have first. Might save you some money. If the flange is out, either get another one, or make one on a lathe.

 

[WobblyHand]

Actually, make sure everything is clean, reassemble and measure the flange play.

 

[aliva]

Have you balanced the wheel? If not there should be a paper washer between the wheel washer nut. mark the paper and wheel with a line using a sharpie, loosen the nut holding the wheel, Turn the wheel mark 1/4 turn, direction doesn't matter. Tighten the wheel and check for wobble keep doing this till the wobble is gone, or least minimized.