To hold a constant angle...

[Edgepal]

This is a very simple but effective tool that show how many degres you wobble sueingvfreehand sharpening on an benchstone. 

I have use a piece of brass 15x3 mm, a strong magnet and a laser pen fixed on the brass part with a rubber band. The brass part have a angle of 10 degrees, make that angle about 15 degrees.

I also made a "target" for the laser dot. The target shall be 54 cm behind the cutting edge = 1 degree = 1 cm on the target.

Do as you are use to do when you sharpen a knife. Mount my tool on the blade. Put the target behind the sharpener 54 cm from the cutting edge. Adjust "zero" on the target where the red dot are when you sharpen. Now, can you hold a consitent angle the red dot will stay on the zero line...

1 cm up, or down, you wobble 1 degree.

Use a video camera and do not look at the red dot, concentrate on the sharpening process and to hold a consitstent angle. Then, look on the video 

I think you will be amazed 

Thomas

[Mark Reich]

Mind Blowing! Holy cow, what will this Forum come up with next?!

[Edgepal]

Happy you like the tool Mike

It is very usefull and can be used in many ways - and in many different distances.

From a working bench can you use a wall as target 5 meters away - and adjust in 10 or 100 parts of 1 degree.

Lay a blade flat on a bench (on a piece of wood or something that lifts up the blade) , point a laser dot in 45 degree angle on its side - and you get a line on the target from the reflektion from the blade, if the blade are flat, you get a line on the target that is vertical (0 degrees).

Move the dot to the edge and you get a line on the target in the degrees the edge have.

I use laser when I will study if my tools are steady during use and that it holds the angle. I use it to se if my guide rods are steady and straight.

The most funny use is on knife Fairs and when a "know it all" Guy come and tell all spectators that sharpening tools are crap and there is no problem at all to hold a constant angle by freehand if you are a real man" you know the type
I talk he into to test my laser tool on the target - and when he do, all spectators start laugh very high, the red dot is all over the target and sometimes not on the target at all. Then I show the same thing on my tool - and the red dot stay on the horisontal zero like.

For the same pupouse I have a knife with three facets, 9, 10 and 11 degrees. The facets are polished and I ask "hard core guys" to grind in 10 degrees - and not scratch the other facets no one can do that by freehand sharpening.

A sharpening tool must be steady to be able to get a 100% flat edge. If the tool is not steady, the edge will be convex, if the guide rods are not steady, the edge will also be convex. If the guide rod are not straight, the edge will be convex - and so on.

If something on the tool can move, for example swing the blade around, the laser shows if the blade angle changes between the blades position - and the change could be meassured in degrees if wanted.

I experimented with a extra equipment that could swing the blade - but I never reach the precision I wanted to have, that is why I use magnets to hold the blade fixed on the grinding table. If something strange appears on the blade during sharpening - I know that it cannot be the tool that makes it appear.

But, this laser tool are easy to make - and it shows very clear how much you wobble during the sharpening process. Most people are not awere about that they wobble. This laser tool tells them that they do - and how much - in degrees. When they know THAT they wobble - they can start to minimaze the wobble, that is a good thing

There will still be people that claim that they can, by freehand, hold a consitent angle. If they do, they can, with this laser tool, prove it with a video that show how they do it . No video - and their climes just blowing away in the wind...

Thomas

[Edgepal]

drawing made in Sketch Up.

Thomas

[EOU]

Ingenious idea Thomas and a very nice drawing! We're with you. If you don't give us something to lean up against we may just fall over.

[Edgepal]

EOU,
I think you allready have understand that I allways write to much. I have a "Thatcher syndrome" and I over- explain things

I have learn on Fairs to explain things as simple as possible. There I have very short time to explain very difficult things. Here I write on a languish that Is not my languish and where I do not have any variations of words - so I think I am over-explain things to be certen that my message was understood

One other thing is that I am a member on many forums and now I am a member here - and this forum has more knowledge and understanding then other forums normally have... That is a great thing that I am not use to

I ahall tell you a story...
When I started with sharpening tools I made a tour during the summers in Sweden and Norway and visit knife Fairs, it was very dun and I enjoy it a lot. I learned very fast that old knife knowledge was gone and I learn to talk very simple and Basic things that the visitors understood.

Innthe end of the summer i was in north Norway and I heard about a New fair up innthe mountains kn a valley that are isolated during the winter month - so I went to that fair.
I put up my tent in the morning, put up my tables ans empty a Box of tools on the table just as a old man passning by. He look at my tools that lay on the table in a big help and he stop, point at my tools and say "i like to by that tool from you" (no tool was conected to a knife). I look at him and smile "do you know what this tools do" I ask him. He look at me as I was the biggest fool he ever have met (and I probebly was) "of cause I know, they give me a flat edge on my knife" he say a little angry. I was very surpriced and try ro explain how my tools work - and he say "i know hiw they work". He by the tool and went away.

Soon after comes a lot of people to my tent and every body by a tool for knife sharpening. Indonesien hour I have sold everything I had. I talk to my son by phone and tell him to get more tools and meet me onnthe border to Norway, he sid that - ans the next day,mthe dirst houers, I sold out eveeything again - and I dound out that the people that lived in this valley know more about knifes, edges and sharpening then I so - also both boys and girls around 10 yeras of age. It was two wonderful days for me, I learn a lot if things - and I later understood that the people inthosein valley was experts of whittling. They was born with a knife in their hand - and use the knife 8-10 houers every day and whittle art things in wood and sell them all over the world - and that this valley was famouse for just this

So, this was a wonderful experiance for me and I get a warn feeling inside when I talk about this valley.

Thomas