very slight stone wobble

[gkirkendall]

Is is common to have to true the stone when it is new?

Just got it at the Houston show this weekend.  Sharpens great, but I have noticed a slight wobble in the stone.

DVD was very helpful in setup.

Thanks

[Jeff Farris]

Is the deviation up and down or side-to-side?

Side-to-side deviation of up to 1/16th of an inch is normal, and within spec.  It can be minimized by removing the stone and scrubbing the hub area of the inside of the stone with the coarse side of the stone grader. Minor imperfections in the stone are causing it to mount at a slight angle to the shaft.  By scrubbing the hub area, you can usually smooth away the high spot, and bring your wheel into a truer alignment.  

Up and down deviation is caused by an out-of-round stone, and can only be corrected by using the ADV-50D diamond truing tool.  It is rare for a new stone to be out-of-round, but not completely unheard of.  

[gkirkendall]

It seems mainly side to side.  I will try scrubbing the hub area a little.

I can feel/hear the wobble a little as I am grinding something, but it is in no way severe.

Thanks for your quick response.

[gkirkendall]

The stone was wobbling vertically some.  I trued it with the truing jig and it was nice an even.  Hopefully the shaft is straight and it was just the stone.

Sharpened a few knives a hatchett and a chisel and it worked wonderfully.

[Ed]

It would seem to me that a stone that is out of round or not squared at the axel, should be found at final inspection and rejected and reworked.
Or is Tormek relying on the customer to rework the stone for them and if so do they even have a final inspection station before boxing up the unit

[Jeff Farris]

Ed, you can rest assured that few machines of any kind made anywhere in the world are inspected as carefully as TORMEK are.  

A stone being out of round is the result of using the machine.  It is virtually impossible not to get the stone out of round eventually.  It normally happens after several hours of use, but new users may see it quicker since they are not as adept at using the machine and usually are trying to sharpen everything in the shop all at once with their new system.  Every grindstone on every grinder in the world is subject to the same forces.  Any slight inconsistency in the stone composition or any accidental extra pressure on the stone can start extra wear at one point, which snowballs into an egg shaped grindstone.  The difference with a TORMEK is that there is a way to deal with it.  The optional ADV-50D Diamond Truing Tool will let you recut the stone back to straight across, parallel with the Universal Tool Support, and concentric.  With just about every other competitive grinding system on the market, when it goes out of round you are out of luck.  

As for side-to-side deviation, that is a different (and much less serious) problem.  Folks who see their stone wobbling side to side usually assume one of two things is wrong.  They either think that the shaft is bent or they think their stone is warped.  In 99.99999% of the cases, neither is true.  The most common cause of a stone wobbling side to side is that the stone is mounted on the shaft at a slight angle.  This is usually caused by a slight variation in the stone at the hub area.  When the stone is forced against the inner hub washer by the retaining nut, the variation locks the stone onto the shaft at an angle other than 90 degrees.  This is why I suggested using the stone grader to scrub the hub area to smooth out any variations.  While a deviation of 1/16th of an inch will not affect performance of the machine, you can usually minimize or eliminate any deviation by scrubbing the hub area of the stone and fiddling with the position of the inner hub washer -- looking for the sweet spot.