Diamond wheel width inconsistencies?

[Kavik]

I recently had the opportunity to pick up the full set of Tormek diamond wheels, lightly used, at a great price, along with the MB-100 for side grinding. 
I was going through a few chisels, trying to get used to grinding on the sides of the wheels, and started noticing angle changes after swapping wheels.

I thought it was related to the amount of metal being removed, so i took one that was finished shaping and got it set back up, colored the bevel and found the angle on the coarse stone.  Without any grinding I then swapped to the fine stone, re-colored the bevel and checked again....i had to raise the micro-adjuster by 3 to get back on the right angle. Tried again with a jump from coarse to extra fine, and had to raise it by about 4 1/2.

I checked that all the mating surfaces are clean and free of debris, i don't notice any wobble, rotating the stone/washer before locking down made no difference.  Tried taking some width measurements around the rims of each stone, they all seem pretty close to eachother.  I guess that just leaves inconsistencies in the offset at the hubs?

Anyway, just wondering if others have noticed the same issue?

[cbwx34]

...
Tried taking some width measurements around the rims of each stone, they all seem pretty close to eachother.  I guess that just leaves inconsistencies in the offset at the hubs?

Can you measure how much the shaft sticks out after you mount a stone?  Might give you a clue if it's the offset?

[Kavik]

Can you measure how much the shaft sticks out after you mount a stone?  Might give you a clue if it's the offset?

A good idea, but i went a different approach.   Straight edge across the center of the back of the wheel, across the hub, with feeler guages.

• Coarse wheel - hub is .004" higher than the edges of the wheel
• Fine wheel - hub is .006" lower than the edges
• Extra Fine - hub is .003 higher than the edges

Doesn't sound huge, but definitely enough to make a difference, and makes it not quite so "swap wheels and keep all your settings the same" as they advertise, unfortunately 

[tgbto]

Hello,

My english is not good enough that I can understand what's wrong with your wheels. Do you think you could sketch it ?

Cheers,

Nick.

[Ken S]

Kavik,

You should email Tormek support. (support@tormek.se)

Ken

[cbwx34]

Can you measure how much the shaft sticks out after you mount a stone?  Might give you a clue if it's the offset?

A good idea, but i went a different approach.   Straight edge across the center of the back of the wheel, across the hub, with feeler guages.

• Coarse wheel - hub is .004" higher than the edges of the wheel
• Fine wheel - hub is .006" lower than the edges
• Extra Fine - hub is .003 higher than the edges

Doesn't sound huge, but definitely enough to make a difference, and makes it not quite so "swap wheels and keep all your settings the same" as they advertise, unfortunately 

That doesn't account for the amount of adjustment you're having to make.  Measuring the shaft should account for this plus any difference in stone width.  If nothing else, it should tell you how much adjustment you'll need to make between wheels a bit more accurate than the Sharpie method.

I'll be curious what support has to say.

[Kavik]

Kavik,

You should email Tormek support. (support@tormek.se)

Ken

I was more just curious if this was a common issue.  I would've contacted them if these were brand new wheels, but being that I bought them used....I wouldn't really expect them to have much to say about it?

[Kavik]

]

That doesn't account for the amount of adjustment you're having to make.  Measuring the shaft should account for this plus any difference in stone width.  If nothing else, it should tell you how much adjustment you'll need to make between wheels a bit more accurate than the Sharpie method.

I'll be curious what support has to say.

You're right, it doesn't give the whole picture...there has to be a difference elsewhere as well.  But with the machined inset on the outside of the wheels, the shaft protrusion wouldn't give the full story either. I would assume the other difference is in the width of the wheel itself, but that's a little difficult to measure exactly, without risking damage to my calipers from the diamonds.

I'll see if I can rig something up later today to measure the absolute location of the sides of the wheels while mounted on the machine.

As I mentioned to Ken, i didn't bother with contacting support because these wheels were bought used.  And, for that matter, they're mounted to an old SG2000 that I bought about 5 years ago, and who knows how old it was at that point lol  The only thing I've ever had a warranty on is a couple of the jigs 

[cbwx34]

...

As I mentioned to Ken, i didn't bother with contacting support because these wheels were bought used.  And, for that matter, they're mounted to an old SG2000 that I bought about 5 years ago, and who knows how old it was at that point lol  The only thing I've ever had a warranty on is a couple of the jigs 

I'd still ask them... it's not really a warranty issue, more of just here's the problem, any suggestions?  If you watch some of their recent videos, they have a lot of "tips and tricks" that aren't in the manual, where they've solved other issues.

You're right, it doesn't give the whole picture...there has to be a difference elsewhere as well.  But with the machined inset on the outside of the wheels, the shaft protrusion wouldn't give the full story either. I would assume the other difference is in the width of the wheel itself, but that's a little difficult to measure exactly, without risking damage to my calipers from the diamonds.

Just cover the diamonds and measure to that on each wheel (if that makes sense)?  (You're just looking for the difference).

[Ken S]

I seem to have a different opinion of Tormek support than some of you. I base my opinion on years of corresponding with support. I have found support very helpful. I would like to share one example:

I contacted support about the occasional complaint we receive on the forum with frozen grinding wheels with the EZYlock. With pre 2006 non stainless steel shafts, this was another matter. Support set up some tests and found two possible culprits: 1) The EZYlock was not GENTLY snugged. Turning on the motor automatically tightened the EZYlock. This sounds good in theory; however, sometimes using the motor overtightened the EZYlock.
2) Support set up tests with lubricating or not lubricating the spacer washer. With the washer dry (not greased), support was able to get the EZYlock to freeze up. With a light coating of grease just on the face of the EZYlock facing AWAY from the grinding wheel, support was not able to get the EZYlock to seize. I suspect that greasing the spacer during the routine at least annual cleaning and regreasing the nylon bushings would solve this problem.

I felt this service was above and beyond. It reinforces my confinence in Tormek support.

Ken

[cbwx34]

Just for a bit of reference I measured the width of my diamond wheels (using the depth gauge to a granite flat surface)  I averaged  50.4mm on the DC to 50.2mm on the DE.  (So that accounts for one of your 'clicks' on the microadjust I guess).

Maybe the reality will be to realize there is a difference when changing wheels, and adjust accordingly?  Just out of curiosity, does Tormek actually say you can switch wheels without adjusting? (Maybe it's an assumption we're making).   After all, you should only have to go thru all 3 wheels once... then touchups should only take one.

[Kavik]

I seem to have a different opinion of Tormek support than some of you.

I don't mean to imply they aren't supportive, i know they are.  I simply figured this wasn't something to pester them with.
I'll consider it, after i get my measurements really nailed down here.

The only fix I can think of, after getting everything measured out, would be adding custom washers between the back of the wheel and the spacer that sits between the machine and the wheel. But they're need to be very precisely machined, and i'd have to keep track of them for swapping on with each wheel.

But that's if I want to be really anal about it, I suppose.  It's not all that hard to just re-color the bevel and adjust a bit as needed between wheel swaps

[Kavik]

Just for a bit of reference I measured the width of my diamond wheels (using the depth gauge to a granite flat surface)  I averaged  50.4mm on the DC to 50.2mm on the DE.  (So that accounts for one of your 'clicks' on the microadjust I guess).

Maybe the reality will be to realize there is a difference when changing wheels, and adjust accordingly?  Just out of curiosity, does Tormek actually say you can switch wheels without adjusting? (Maybe it's an assumption we're making).   After all, you should only have to go thru all 3 wheels once... then touchups should only take one.

I had also thought about using a depth gauge and a granite plate, but ruled it out once i realized one of the hubs is higher than the wheel, and the other two are lower, so even that wouldn't give a proper view of how they compare when mounted.

I don't actually know if they ever specifically came out and said about switching without adjusting.  I just remember seeing that discussed as a big benefit of the diamond wheels....granted, I'm sure that's mostly on relation to the outer diameter not changing when the wheel wears down, like the stone ones do.....but, yeah, i guess I just assumed there'd be a high level of accuracy for the side grinding as well.

I'll report back once I get my measurements taken on my lunch break

[cbwx34]

I had also thought about using a depth gauge and a granite plate, but ruled it out once i realized one of the hubs is higher than the wheel, and the other two are lower, so even that wouldn't give a proper view of how they compare when mounted.

I don't actually know if they ever specifically came out and said about switching without adjusting.  I just remember seeing that discussed as a big benefit of the diamond wheels....granted, I'm sure that's mostly on relation to the outer diameter not changing when the wheel wears down, like the stone ones do.....but, yeah, i guess I just assumed there'd be a high level of accuracy for the side grinding as well.

I'll report back once I get my measurements taken on my lunch break

Yeah, I'm just looking to see where a difference may or may not be.  I don't see any difference between the hubs on mine, (although I didn't measure), so was looking at overall width.

Like you, I've only seen the constant size in reference to the diameter.

... But they're need to be very precisely machined, and i'd have to keep track of them for swapping on with each wheel.
...

Just stick it to the wheel. 

[Kavik]

Yeah, I'm just looking to see where a difference may or may not be.

Well, lunch break didn't happen, but got the measurements done tonight. The answer is the differences are a little bit on every surface lol
Different wheel width on 1/3, different backspacing on each, different depth from the face of the wheel to the surface for the nut. Most importantly, different overall hub to face widths.


I took the time to take averages of all measurements taken at 4 points on each wheel.

Outer ring wheel widths:
Coarse: 50.28mm
Fine: 50.12mm
Extra Fine: 50.12mm

Actual height from hub face to wheel face:
(measured with your granite plate/depth Guage suggestion, but with the hub sitting up on a 1-2-3 block, so the offset isn't factored.  This would simulate actual measurements while mounted to the machine.)
Coarse: 50.36mm
Fine: 49.86mm
Extra fine: 50.16mm
Largest difference of 0.5mm

After that, i mounted each wheel to the machine and confirmed measurements using the USB.  The differences between the distance to the wheel faces matched the measurements above perfectly.

Keeping track with the micro-adjuster as I went, i found the following...
To keep the distance to the USB the same, using the coarse wheel as the baseline of 1:
Switching Coarse to Fine, need to lower the USB 2 full notches.
Switching Coarse to Extra Fine, need to lower USB about 1.25 notches (in other words, if going from Fine to Extra Fine, would need to raise the USB about 0.75 notches).

So, it seems 1 notch on the micro adjuster is equal to about 0.25mm of bar height, is that about right?  I know that info is out there somewhere, but I don't recall.

I'll use this as a rough guide, but will still double check with the marker when switching wheels.