Topic: My way of mounting knife in SVM-45 jig

[sandor]

Many of us have encountered problem with mounting knife in the jig and subsequent sharpening a bevel symmetric with respect to the blade axis. Below there is my procedure which I use for some four years.
1-    Insert the knife in the SVM-45 jig.
2-    Tighten the small screw No.3.
3-    Fix the position with knob No.4.
4-    Tight and fix so, that the jaws form a parallel gap = red lines in the picture.
5-    Put the knife jig on the T7 stone, but do not start the motor.
6-    Align the Anglemaster WM200 with loosen right angle setter knob.
7-    Tighten the right angle setter knob. The angle is fixed (no matter how large it is now).
8-    Flip the knife jig.
9-    Align the Anglemaster WM200 and look where the light shines through. If the light does not shine through, the knife is mounted.
10-    When the light shines through loose the knife jig knob No.4 and revolve the screw No.3 by 15° to the right or to the left. Practice will tell you the direction and size.
11-    Repeat the procedure from step 3.

Thank you Jan for translation

[Ken S]

Welcome to the forum, Sandor. I will have some quiet time to work with your knife setting technique. I look forward to it!

Ken

ps Thanks, Jan, for translating.

[Jan]

Welcome to the forum, Pavol Sandor! 

Guys, Sandor is a Hero member and guru of the knife.cz forum which has a Tormek machines subforum (http://www.knife.cz/Default.aspx?tabid=53&g=posts&t=22970&p=37). This forum serves knife makers and sharpeners from the Czech Republic and Slovakia. Sandor is very experienced knife sharpener known for his microscope bevel inspections and many other innovative approaches.

Correct knife mounting in the knife jig is crucial for obtaining symmetrical bevels on both sides. The kenjig concept assumes that the blade was mounted correctly – centred to its centreline.

In 2015 Wootz started topic concerning the knife jig asymmetry problem http://www.tormek.com/forum/index.php?topic=2577.0 To minimize the bevel asymmetry caused by large blade thickness he filled away several mm from the static clamp.

Based on my recent geometrical modelling incorrect knife mounting in the jig can result in bevel asymmetry much larger than the one caused by excessive blade thickness. 

Jan

[Ken S]

Pavol,

You have very interesting thoughts. I can certainly see how your method will reduce errors.

I had a few minutes tonight to try your method with my SVM-45 and kitchen knives. My paring knife worked very well. I found my chef's knife more difficult to center. It is a traditional Henckel with a bolster, a rather thick knife. I will continue working; I think you have a valuable idea.

Ken

(Thanks again for translating, Jan.)

[Jan]

For grinding and polishing of small components I use a little hand vise clamp. The jaws open and close by turning the handle (max. 6 mm). This vise has self-centring ability. 

I am wondering if this simple principle could be applied in knife jig design also? If the jaws are made pivotable they could grip tapering blades also. 

Jan

[Ken S]

In the US, a popular classic car is a "'57 Chevy" (a 1957 Chevrolet). It has a two speed transmission. My grandfather owned one in 1957;it was the family car. Today I drive a 2011 Chevy Equinox. It is a garden variety small car, certainly not a high performance vehicle. However, it has a six speed transmission. We have higher expectations today.

The standard Tormek knife jigs have served well for decades, and continue to do so. However, today we have a small but growing number of users who would like higher performance. We would like the jig to be self centering to compensate for variations in knife thickness. We would like the jaws to pivot, to accurately grasp tapered knives.

Such improvements will probably not play well with the general Tormek buyer. My SVM-45 cost $29 US back in 2009. It costs $39 now. Tormek could make a knife jig as precise and versatile as the DBS-22 drill bit jig, a marvelous jig costing more than $200. Such a knife jig could easily cost $100. I would gladly purchase one, as would a number of forum members. Of the forum members, we might realistically purchase perhaps twenty units. Professional sharpeners might welcome the new jig, but sales would be nowhere near enough to justify the cost of production. That is an unfortunate reality.

Jan, applying your small hand vice technology to the Tormek is an outstanding idea. I hope Sweden has read your post and is considering the idea. I hope the engineers can convince the accountants. Who knows, maybe someday cars will have six speed  transmissions. I live in hope.

Ken

[Jan]

In the US, a popular classic car is a "'57 Chevy" (a 1957 Chevrolet). It has a two speed transmission. My grandfather owned one in 1957;it was the family car. Today I drive a 2011 Chevy Equinox. It is a garden variety small car, certainly not a high performance vehicle. However, it has a six speed transmission. We have higher expectations today.

Ken, grandfather of my best school friend was a car designer. His car Disk was built in 1924 and had no gearbox but unique friction transmission. My friend inherited motor and plans and build the veteran from scratch. 

Jan

[Ken S]

Wow! I'm impressed. Best of luck to your friend.

Ken

[Jan]

I would not abuse our friendship but in my thinking design of a self-centring knife jig would not be a very difficult task for him. 

Jan

[Ken S]

Go to coffee with him and during a pleasant coffee time subtly mention the forum comments about hoping that someone on the forum would develop a self centering jig.......... 

Ken

[Jan]

Such improvements will probably not play well with the general Tormek buyer. My SVM-45 cost $29 US back in 2009. It costs $39 now. Tormek could make a knife jig as precise and versatile as the DBS-22 drill bit jig, a marvelous jig costing more than $200. Such a knife jig could easily cost $100. I would gladly purchase one, as would a number of forum members. Of the forum members, we might realistically purchase perhaps twenty units. Professional sharpeners might welcome the new jig, but sales would be nowhere near enough to justify the cost of production. That is an unfortunate reality.

Ken, you are correct! The self-centring knife jig could be offered as an option for professional knife sharpeners. Imagine "The Unbearable Lightness of Being" with such a jig. 

The price circa $100 is a small part of the sum Wootz invested in his unique set of jigs for different knife thicknesses. 

Jan

[Ken S]

Good point, Jan.

I had some simple machining work done on my Porter-Cable Omnijig (dovetail router). This was around ten years ago, and cost $125 US. It was a fair price for quality work. If I had the work done on ten of fifty units, the unit price would have been considerably lower.

You are correct, such a high powered knife jig would be an option for professional sharpeners, just as the T2 is for professional chefs and restaurant owners. I think the idea has promise. To help keep the cost down, the design could incorporate interchangeable jaws for regular and longer knives. The interchangeable jaws could also cover very thick knives.

I look forward....

Ken

[Elden]

Jan,
   Snapper riding lawn mowers have used a similar type drive for many years. It is possible that their idea was obtained from such as you posted.

Ken,
   I imagine it would take more than $100 USD to purchase such a knife jig. As you were saying, "supply and demand" would play a big factor.

[Jan]

Elden, the grip of the hand vise is surprisingly firm. For functional knife jig it would be necessary to preserve the achieved force amplification while keeping the clamps thin. 

Jan

[Ken S]

A professional knife sharpener might look at price differently. Any sharpener who is concerned enough to be interested in a self centering jig will be catering to a more sophisticated customer, and should be charging accordingly.  A jig which allows him to reach this precision easily would be a good investment. Payback time with higher sharpening fees would be quite reasonable, even at more than $100. I believe there would be a market for this jig, just as there is a market for the DBS-22.

I also believe the market would include advanced amateurs like me.

Ken