Sharpening Chisels- Toolrest Not Square

[Kevin]

I keep on running into problems when I sharpen chisels.  The chisels sharpen to a nice edge, but the edge is not 90 degrees or square.  The chisels are mounted up against the two posts to keep the chisel straight, but the chisels end up crooked.

The toolrest is not remaining square to the grinding wheel, and the out of square angle shows up as a sharpened edge that is not square.

I end up tuning the chisel a little to the left or right to compensate for the toolrest not being square to the grinding wheel.

Has anyone found a good way to ensure that the toolrest is square or prallel to the grinding wheel?

I think that will cure the problem with the chisels being sharpened out of square.

[Jeff Farris]

The problem is not the toolrest, (Universal Tool Support), but how you are clamping the tool in the straight edge jig.

Click on this link and take a look at this tech sheet.  I think it will help you.

http://www.sharptoolsusa.com/squareedgeweb.pdf

[Kevin]

Thanks for the advice.

The chisels are square in the SVH-60 jig.  I checked that with a machinist's square.

Thr problem is that the universal tool support is not held square when it gets clamped to the machine.

I tried Torgny's advice to tweak the tool in the SVH-60 jig, and the "simple adjustment procedure" in the third paragraph of the tech sheet.  The procedure does not work to change the angle of the tool in the jig, nor does it change the "short point", "long point" thing to make the chisel square.

The problem is that the universtal tool support is not held square when it gets clamped to the machine.  The clearance between the universal tool support and the location where it gets clamped into the machine allows the universal tool support to be out of square.  If there are any tolerances with the machine, that can also cause the universal tool support to be out of square.  If the universal tool support is out of square, adjusting the SVH-60 jig to be square is hopeless.  The chisel will be out of square to the same amount that the universal tool support is out of square.


*This is NOT the problem that I am described above; it is a suggestion to improve the SVH-60 jig.

The SVH-60 jig could be much improved if the two things to hold the chisel square were lengthed to be taller.  A lot of chisels have clearance cuts on the side, so the two little posts to keep the chisel square are too short to contact the chisel.

Thanks

[Jeff Farris]

Kevin, I believe you are trying to over-think this problem.  Going back to the tech sheet, the first thing that we recommend is that you insure that the stone is parallel with the Universal Tool Support.  If it is not, then use the truing tool to cut the stone parallel to the Universal Tool Support.  The only thing that matters in alignment between the two is parallelism.  The Universal Tool Support can be out of square by an enormous amount, but if the stone surface and the horizontal beam of the Universal Tool Support are parallel, the machine will function as designed.  

Kevin wrote:

The procedure does not work to change the angle of the tool in the jig, nor does it change the "short point", "long point" thing to make the chisel square.

I am going to have to respectfully disagree.  I do this adjustment 50 or 60 times every weekend when I am demonstrating the TORMEK.  Every demonstration I check the squareness of the tool and adjust the pressure on the clamps to roll the tool whichever way is needed.  

[Kevin]

Thanks for the reply.

I am not sure how to ensure that the UTS (Universal Tool Support) is parallel to the stone every time.

The UTS can be mounted in the two supports and clamped down with the knobs, but that does not mean that the UTS is parallel to the stone.  I can make the UTS slant to the left or slant to the right, and it can be different each time.  There is nothing to force the UTS to remain parallel to the stone or at least ensure that the UTS is canted the same way each time.

In theory, I can true the stone every time I reattach the UTS or even adjust the the UTS up or down, but truing the stone that often takes its toll on the stone.  (The stone is expensive.)  Also, the diamond cutter does not ensure that the stone is parallel to the UTS.  The diamond cutter is a point, not a line, so the diamond cutter does not force the stone to be parallel to the UTS.  I can use the diamond cutting tool to make the stone tapered to the UTS, because it cuts one point at a time.

In other words, the mounting mechanism for the UTS allows the UTS to be out of parallel in a different way each time the UTS is mounted or adjusted.  That out of "parallelness" is then projected to the chisel.  The chisel is out of square the same amount that the UTS is out of parallel.

You can see the same thing for yourself when you put the UTS in the two mounting holes.  The UTS can be canted to the left or to the right.  There is play between the UTS and the mounting holes, and that play makes the UTS out of alignment.  The misaglignment is different each time the UTS is mounted or adjusted; that is the problem.

That is not a problem when I sharpen knives or scissors (due to the design of those jigs), but it is a problem when I try to sharpen chisels.

I am looking for a good way to mount the UTS and ensure that it is parallel to the stone.  There has to be some sort of gauge design that can be made to ensure that the UTS is parallel to the stone.

I will try the adjustment procedure that you mentioned again to micro-adjust the chisel.  Maybe I was missing something?

I am still pleased with the Tormek sharpener.  I think that an improvement can be made to ensure that the UTS is parallel to the stone via some sort of gauge.  Moving the chisel to the left and right can correct for SOME misalignment of the UTS, but it cannot correct for all the misalignment.

[Jeff Farris]

 Moving the chisel to the left and right can correct for SOME misalignment of the UTS, but it cannot correct for all the misalignment.

Yes, it can.  In fact, it can probably correct ten times the misalignment  that you could introduce by forcing the UTS right or left.  By the way, as I have mentioned before, we are not moving the tool right or left, but rolling the tool right or left.  

Just to drill a little deeper into this issue, I feel that I have to point out that if you could design a UTS that moved perfectly parallel up and down without every varying (and anyone could actually afford to buy it) that we are still dealing with abrasives.  The stone is going to cut at and wear at varying rates depending on the steel being cut, the pressure being used, the presence or absence foreign substance on the tool being sharpened, and probably a couple dozen things I am not thinking about at this moment, including whether you are right handed or left handed.  

Also, the diamond truing tool, when used correctly, will absolutely cut the stone parallel to the UTS. That line cut by the ADV-50D is parallel to the UTS, since it is triangulated from the yoke and the UTS.  Whether or not the diamond tip is cutting with one point or half a dozen, if it is passed across the stone slowly, it can only pass in a straight line parallel with the UTS.  Yes, you are technically correct that when you move the UTS up or down it may not lock in on exactly the same plane, but the difference is inconsequential and any operative anomaly (as in out of square edges) is coming from somewhere else --- most likely inaccurate clamping pressure on the SVH-60 clamping bar.  

[Brian]

Another question on chisels. I am new to this and seem to be able to achieve the 90 degrees, but the chisels I currently own seem to have short tool lengths. They end up resting against only the lower side alignment rest. If you align against both, the jig would have to rest on the stone to replicate the bevel angle. Any tps/ tricks on this?

Thanks

[Jeff Farris]

Short chisels can be handled two ways.  The first is to use the SVS-32 Short Tool Jig according to the instructions in the Owner's Handbook.  An alternative is to push the tool further into the SVH-60 Straight Edge Jig (past the rear alignment pin), apply light tension to the clamping bar, and then square the chisel to the front edge of the SVH-60 using a machinist's square.

[moondog470]

Could it be that the sleeves the UTS goes into need to be adjusted to take out some of the slop that is being complained of?  I think in another post where the poster was saying that he had a hard time lifting or lowering the UTS you said the sleeves could be adjusted to compensate for the variance in the distance between the legs of the UTS.

[Jeff Farris]

Could it be that the sleeves the UTS goes into need to be adjusted to take out some of the slop that is being complained of?  

I think Kevin was creating problems that didn't exist to explain a problem he was having.  Yes, you can induce some variation by TRYING, but if you will just adjust the Universal Tool Support up and down normally it will maintain the same relationship to the stone to a degree of accuracy necessary for tool sharpening.  The only time I would adjust the sleeves is if the Universal
Tool Support is too tight.  I have never had one that I considered too loose, and in doing the shows I have assembled several hundred machines.  

[Kevin]

I like the tool grinder, except there is no way to make sure that the UTS is parallel to the grinding wheel's cutting surface.

The single point-dressing tool can "true" the surface of the wheel with a taper to the side or even to an out of round condition.  There is no way to true the wheel flat or parallel to the UTS.  I can true the grinding wheel on a surface grinder just fine, because the parts are rigidly held in alignment during the truing process.  The XYZ table ensures that the alignment is square.  The UTS can get out of alignment when the screws are loosened to move it up or down.  I can measure how crooked it gets, and it is significant when sharpening chisels.

If the UTS is moved up or down to adjust the height, the UTS to wheel relationship can go out of parallel.  There is nothing to ensure that the UTS and grinding wheel are parallel.

That condition is not a problem when sharpening knives or scissors, but it shows up time and time again when sharpening chisels.

[Jeff Farris]

Kevin, you are looking for a level of precision that is neither necessary nor advisable for tool sharpening.  True your stone on a surface grinder??? Of course you could get it perfectly true, but the instant that you start using it, it is no longer perfectly true.  Abrasive wheels wear.  If they don't, they aren't working correctly.  

The ADV-50D trues the wheel to a degree of accuracy more than acceptable for the job at hand.  

[The Fat Chef]

I am a newbie and I too was having problems with evenness and square of my hand chisels. I spoke to Jeff and he gave me a very simple solution. Make sure that you don't over tighten the thumb screw on the jig. Now all is fine and quick.

Also, Jeff gave me a bit of advise for new owners. Wax your machine using car wax.

I've had the machine for 10 days and have resharpened all of my knives (I am a professional chef) in a matter of minutes for each.

(never trust a skinny chef)