I recently bought a Delta slow speed grinder for the initial sharpening of my chisels and plains. Straight out of the box, both wheels wobble, one more than the other. I’ve been reading reading threads on this forum re: wobble and out-of-round wheels. I believe however, that forum members have been talking about wobbles on the edge of the wheel which can generally be solved by dressing the wheel with star or diamond dressers. My concern is that the wobbling I’m experiencing is on the SIDES of the wheels. I’ve replaced the flange-washers with dead flat sideswashers and I’ve reset the wheels, as described in early posts, 1/4 turns from the shaft with some improvement.
How can I eliminate the remaining side wobble? Could it be dressed in the same manner that the edge can be dressed? Aside from attempting to sharpen drill bit tips, how important is eliminating side wobble?
Replies
You should never use the side of the wheel for grinding. Catastrophic failure can result.
1 - never use the sides of the wheels for anything.
2 - side wobble doesn't really matter, although it might make the entire grinder wobble a bit.
3 - most of the time it's caused by bad machining on the axles or washer.
4 - leave the wheel alone
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Spalty,
I am afraid that I have to disagree with the last two posts.
Have a look at those wheels and tell us where they are manufactured: these days I have reason to use a variety of grinding wheels, and I notice that Norton wheels, for example, are made in Australia. The very same wheel is also made by Norton in China and guess what? The Chinese ones wobble and are out of round....
No problem once they are dressed true- I don't notice any difference in performance and so far none have disintegrated. (Never had an exploding wheel, or known of an example of this).
So,assuming that the arbor and flanges are not at fault and that the correct bushing is in place, I think you should dress the wobble and out of round out of any wheel even if it is on a "slow" grinder. A diamond dresser does the job easily. The tee bar type is easier to manage and will do the side wobble as long as there is not much to come off, otherwise you can use a single point but it must be supported by the tool post or some other means. Use this to get it near perfect then finish it with the t bar type.
When you have trued up a wheel it is useful to mark the wheel, flanges and shaft so that if you take that wheel off for any reason you can replace it as it in the same position. Use a sharpy pen for that.
There is nothing wrong at all with using the sides of a wheel for light grinding as in drill bits etc-nothing. You have got to be quite clever to grind twist drill bits on the front of a wheel....but it is fairly easy to to do on the side of the wheel and very little pressure is required, definitely nowhere near that required to deflect and break these wheels, which are in fact very strong provided they are not cracked or damaged.
You ask about the importance of eliminating wobble: 1)I would presume that that Delta item is on the flimsy side so any wobble would cause vibration, even if it is a slow type machine. (Dammit , it is a machine-it should be right). 2)If you are sharpening drill bits you don't want the added complication of a moving target-especially for smaller bits.
I don't like the idea of you having replaced the flange washers... These should be cup type flanges which are intended to apply force equally at a certain distance from the arbor hole- i.e they are lipped. If they are defective the whole thing should be thrown back at Delta. And those paper blotters/washers are most important as well- are they still there?
From Nortons safety poster.Side pressure on thin straight wheels
is dangerous.Most wheels will stand
quite a lot of straight radial pressure,
but there is a limit to what they can
take.Heavy pressure with vitrified
wheels is apt to cause the wheel to
get hot.If it gets too hot too quickly,it
is apt to break.
Sudden bumping or pounding is
more dangerous than steady,even
pressure.
R,
For sure side pressure on THIN straight wheels is to be avoided-anything of 1/4 inch and less especially if it is bigger than 6 inch diameter. In fact thin wheels need great care.Just common sense.
I can't imagine why anyone would want to apply anything but gentle pressure to a typical bench grinder wheel unless they want to light a big fire/joint with the glowing end of the one inch round bar they have forced into the wheel...
I am familiar with the safety warnings of manufacturers such as Norton and 3M. Remember they are vulnerable to the sueing public and the antics of lunatics etc so they always convey the worst case scenario.
I actually think that straight cup wheels, or wheels recessed one side , or shallow dish wheels are a lot more versatile than the ordinary straight wheel- all designed for (intelligent) use on the sides.Philip Marcou
Thanks for your voice of experience and reason. This is my first grinder - I was fed up with spending whole Saturdays hand-sharpening my tools on stones and high-tech sandpaper. I figured I could eliminate 75% of my time spent by using the grinder to do the initial, "rough" sharpening step. I was a bit dismayed at experiencing this problem on what's supposed to be a 3/4 HP, heavy-duty piece of equipment (yeh, machines are s'posed to be ACCURATE, d#%* it!) The replacement flanges were supplied by the Delta after I told them of my plight. They're designed for this machine but are about four times heavier than the flanges originally provided and are a decent up-grade.What do you mean by those paper washer/blotters? The wheels have labels, similar to those on vinyl records, on both sides of the wheels. Am I missing something?The current wheels on the machine are Deltas. I have a Norton aluminum oxide on order. I'm wondering whether the arbor adapter supplied with these wheels will mitigate the wobble. Regardless, I think I'll experiment a little more with repositioning the wheel in relation to the arbor and flanges and then maybe carefully dress the side. Thanks again
One wonders why Delta would supply inferior flanges and then offer functional ones as an "upgrade"- ?? Are we from a different planet?
Those items resembling labels are what they call blotters and they act like compressible washers-they enable the wheel to be firmly gripped without a lot of pressure. They are supposed to be of a larger diameter than the flanges.Philip Marcou
Bench Grinder Side-to-Side Wobble
I feel your pain. I just bought a Jet 8" low speed grinder and had the same side to side wobble. The manual says to "adjust" the outer flange by turning it slightly then retighten and test. Do this until you turn the outer flange one full turn. If that doesn't do the trick turn the inner flange 90 degrees and repeat the process with the outer flange again. What a pain in the......The inner flange has to sit perfectly parallel to the indent on the arbor and the inner flanges outer surface has to sit perfectly parallel on the wheel surface. If the flanges are not perfectly parallel the wheel will wobble. What I can't understand is why a manufacturer like Delta or Jet can't produce flanges where both surfaces are perfectly parallel. I'm sure they have the machinery to do it. So what I did was sand flat the flange surface that goes against the grinding wheel. After I placed the flange, wide side down, on a flat surface I ran it through my drum sander to sand the surface that goes against the arbor. Take very small bites. I noticed how unparallel the two flange surfaces were. This took out most of the side to side wobble. I did this with the inside and outside flanges. I should have taken the flanges to a machine shop and might do that still. Best of luck.
Do you have access to a dial indicator.If so check the shaft.If ok check the face of the inner flange.If the flange is loose on the shaft use some plumbers tape ,stabilize the flaage,and check the face runs true.If either is off threaten to pillory the manufacturer on these pages calling forth all users who have the same problem.
He asked his question in 2008. That wheel an possibly even the grinder is dust by now.
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