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Hi Ken,

I agree with you, home kitchen knives do not require so sharp edge... My wife cuts her fingers too much after my sharpening and I get yelled at! I hope it is not your case.
For me, better sharpening is more of a game. How sharp can I reach...

About my system, when you do your own USB, with a 12mm metal rod, after the classical screw thread, the rod is only 11.8 mm because I cannot do as well as Tormek. Therefore, a solution is to do the screw thread only on a short distance to keep the 12mm rod in the guide. Another solution can be to do screw tread on both legs and use two nuts. Having both solutions at the same time is probably not necessary as many other things can impact the accuracy of the sharpening.

The other things is I have done an excel sheet that compute the USB height while taking into account the thickness and the taper of the blade. And when I try to validate my calculation with practical exercises, I still have some differences.  So I try to remove as much as possible error in the sharpening angle. I do not have time actually to work on it, but I hope I could find my mistake one day...
Best regards

BeSharp,

This is an interesting subject.

I had done my own USB and in order to avoid having a 11.8 mm screw thread in the guide, I have done the USB with only on a small length of thread. I use a pipe, and the screw to set up the right height.
In order to keep the USB parallel to the Tormek, I have done a screw thread on each leg, and I have done a mark on the 2 screws to keep the USB parallel.
I don't think it is as accurate as your system but the setup is probably easier.

As I use only stones, I can use the TT-50 Truing Tool to keep the USB parallel to the USB (and parallel to the Tormek front). This is why, the screw thread is so short. It allows me to use the truing tool while keeping the USB with the 12mm leg part in the guide.

However, this solution does not allow to use this USB in the horizontal position as the screw interfere with the knife jig. 

Regards

Gilles

Hello
As a beginner, I have tried both methodologies: distance to stone and USB height, measured with a caliper. I have found that it was easier with the USB height.
At that time, i did not realize that the distance to stone was more universal.
What I found difficult with the distance to stone is to have the caliper in the direction of the stone center. On this forum, I have found good ideas with elastic strap between the USB and the center of the stone.
Sorry Ken, I have not already try your Kenjig, due to lack of time but I will.

Gilles

Hi john,
There is a very nice functionality in Excel that allows you to do it in the Tormek Calc Sheet. I dont know exactly the name as my Excel is in French.
In the Data Tools group, click the What-if Analysis drop-down and choose Goal seek.
'Set cell' is the USB value
'To value' is the USB Value for which you whant to know the angle
and 'By changing cell' is the grinding angle cell.
When you press OK, Excel search the grinding angle that gives the USB value you have specify.
I hope this answer your request
Gilles 

There are so many interesting things on this Forum, so many kind people. This is my small contribution. Regards

Hi Jan,
This is exactly the conclusion that I have done from this study and you explain it very well: "The consequences are important, both, the real grinding angle and the real honing angle are biased in the same way. This allows successful deburring despite the fact that the bevel angles are biased. "

It is also interesting to notice the effect of thickness and the effect of tapered blade on the bevel angle asymmetry (grinding angle and bevel height).

Tapered blade angle have often more impact than the blade thickness itself. The thicker the blade is, the higher the tapered blade angle can be and the higher the asymmetry can be.

Gilles   

High Rick

Thank you for spending some time to look a my spreadsheet.
I take all the comments as valuable remarks.
I will do a release taking into account all of them.

Concerning the formula I forgot to put in, you found the good answer.

I agree it would be nice to have a sreadsheet with the parameter of every Tormek machines.

Do you know if all those parameters have already been publish on the Tormek Forum or should I create a new subjet to ask the Tormek community to send them to me so that I could include them.


Kind regards

I like the concept describe here, however I think that the jig centering bushing from JVH (//forum.tormek.com/index.php?topic=3918.msg26586#msg26586) do nearly the same thing and is simpler to do. I plan to do one for me soon to try it.

The thing with this eccentric is that it is probably not easy to set up. It needs to be done by successive trials.
I do think that a good solution could be to design a new plastic holder which incorporates the eccentric and an angular graduation (see my drawing).  This could be printed with a 3D printer.  This solution could be very accurate and cheap. I don't have any experience in 3D printing but I am sure it could work. If someone wants to work on it, I would be happy to contribute and to describe more in details my idea.

The shape of the eccentric is already available in my spreadsheet. You can find it there : //forum.tormek.com/index.php?topic=4326.0. I could easily add the calculation required to set up accurately the eccentric based on the knife thickness and the knife tapered shape.

Gilles

Thank you Rich. I think it is a good idea

Hi Jan,

Thank for your comment,
You make me understand why people are using the USB top to stone distance. I will add it in a future release.
I didn't knew the existance of the cental angle theorem, I will have a look at it

Kind regards

Hi cbwx34,
you perfectly understand how to use it.
regards

Hello everyone,
It makes several months, I am reading with very much interest, the different posts and I have learned a lot about sharpening.
This is my first post on this forum and I would like fist to thank all the contributors for sharing their knowledge.
My first Tormek was a T3, and I didn't like it because the USB support was not strong enough to keep the blade of a planer perfectly perpendicular.
Later on, I found a very cheap Tormek 4000, all in stainless steel. I try it in a dark area and I didn't realize that the stone was not a Tormek stone and that the shaft was twisted! After a while, I found someone to make me a new shaft and I bought a second hand Japanese wheel SJ250. This purchase was finely a very good one.
So now I have a SG200 wheel to sharpen knifes and I have a wider wheel to polish them (before the leather wheel).

I have tried to use the TormekCalc² to keep the same angle with the 2 stones but I realize that it was not possible. The second wheel was always grinding the edge heel instead of the edge tip.

I wanted to find the lowest possible knife angle that would polish the tip.
I have spent some time to understand all the formula of the TormekCalc² of JVH.
What is nice with the Tormek problem is that everything can be analyzed through triangle geometry. It is no more mathematic, it is only geometry, nice geometry, and I have solved my problem of polishing angle.
I share with you this spreadsheet that does the same calculation as the TormekCalc² and some more calculation; however this is done with a totally different objective. TormekCalc² is a very user friendly tool (Thank you JVH) and I don't want to compete with it. My aim is to do a very simple spreadsheet so that everyone could understand every formula and modify them as they need.
I took the liberty of using as much as possible the same letter and the same name as in TormekCalc² so that people could understand the drawing and the formula more easily.

I have also study the impact of the knife thickness and the tapered knife on the real grinding angle.
It gives me the idea to realize a Jig centering bushing before I realize that JVH has already realized it.
I have added a sheet dedicated to that.

I hope that my calculations are good. The first trial I have done was OK with a flat piece of steel of 3mm with a single bevel grinding. With the same angle as the grinding wheel, I could see the polishing of the hell and with the correction of the angle, I could see the polishing of the tip. I am happy. It works for that!

I do not have a very tapered knife so I was not able to validate my calculation for that. 

Now that I understand how to use the Tormek, I need to go to practice and play with it.

Kind regards