an aid to help setting bevel angles

[Ken S]

I posted a photo a while back about a metal piece I made up as a flat substitute for a knife blade. After some excellent feedback from the forum, I have made some design modifications.

Alas, I have posted so much that I cannot locate the original post. Finding the photo on my computer may be easier.

Matching the thickness of the metal substitute to the knife jig milled relief (either 2.5 ot 3 mm as I recall-please refresh my memory) seems very logical. I believe Jan made the suggestion.

The other modification is switching from one to a set of tools. One is sized to match a paring knife. One is sized to match my slicing knife. The third is sized to be a substitute for my chef's knife. These offer a larger flat measuring plain for the Anglemaster.

The Anglemaster is a good tool. In my opinion, the substitute targets make it a better tool.
This post is now obsolete. Please see my post below.
Ken

[Jan]

Ken,

the knife jig works fully symmetrically for knives with two sided bevels which blades are about 2.5 mm thick. It is the thickness of the steel guide bar (1) of the Small Knife Holder. 

Important: If you intend to sharpen the substitute like a chisel blade use a 1.25 mm thick piece of metal. This will guarantee that the edge of your metal substitute will be in the same plane as the longitudinal axis of the knife jig. 

If your metal substitute will be angled symmetrically on both sides than use 2.5 mm thick piece of metal.

Jan

[Ken S]

Please forget my set of tools idea. Only one substitute target is necessary. I forgot one of my basic operating principles. Just as any of the three knives in different jigs will produce identical bevels if the Protrusion is set the same, in this case, 139mm, a substitute target will produce the set up for that bevel if it is also set for the same Protrusion (139mm). Therefore, if the substitute target was set for 139mm, it would provide a good measuring surface for the Anglemaster with any bevel angle within a reasonable range.

In fact, if the substitute target was permanently left in a knife jig, either size, The jig could be placed on the support bar and used to quickly and accurately set the bevel angle using the Anglemaster.

Thanks, Jan for your post. It got me thinking.

Ken

[Jan]

Ken,

In my understanding it is not necessary to combine your substitute target concept with the specific protrusion length of 139 mm used in the kenjig concept for new grindstone.

I think your original idea of having three substitute targets of different width was good. 

I recommend to ground a chisel edge on a 1.25 mm thick substitute target because this will minimise the distance between the stone and the flat part of your substitute. The optimal edge angle would be less than 15°. 

Jan

[Ken S]

Jan

Points well taken. I imagined the separate substitutes to be used in the same jig for each knife. You are correct; the Protrusion length need only match the knife, not any particular number. I have just standardized on 139mm for efficiency.

The single substitute works best with its own jig. By staying with 139mm for all kitchen knives I can leave the substitute target preset (semi permanently) in its own knife jig and it can stand in for all my kitchen knives.

For a common bevel angle, I still prefer the kenjig. This substitute target method allows efficient use od the Anglemaster for different bevel angles.

Ken

[Ken S]

Jan's excellent drawing shows the substitute target piece very well. Thanks, Jan.

My thought process seems to need to go through a complicated stage before reaching a simpler solution. The simpler version:

Most Tormek users who sharpen knives have two jigs, the standard SVM-45 and the SVM-140. To use the substitute target, place the knife in the desired jig. Instead of purchasing a dedicated jig, place the target in your other jig. The only difference in the two jigs is the width of the holding surface. Match the Distance of the two jigs by either using a rule, a pencil mark on cardboard or plywood, or by using the method Steve shows on his video crating a rub line on the grinding wheel.

Use the mounted substitute target with the Anglemaster to set your desire angle. No need for a dedicated knife jig.

Ken

[Jan]

You are welcome, Ken. 

Now it is really simple procedure. A.Einstein said:  "Everything should be made as simple as possible, but not simpler".

I have simplified the drawing also and kept only the recommended thickness of the substitute target. 

Jan

[Ken S]

Jan,

Thank you for the simplified drawing. Wise words from Albert Einstein.

Ken