Thank you for posting the link to the related forum topic. I found a very perceptive quote there from Dutchman:
"The distance is measured NOT to the top NOR the center of the support. It is part of the triangle thorough the knife in the jig. So it should be measured to the heart of the jig just above the center of the support. Measuring the distance to the top of the support however will give a negligible error.
Please keep in mind that this subject is not an academic item, but a proposal to simplify the jig-setting
Thank you
"
While I appreciate the very high level of precision being used in this process, for me, Dutchman's last sentence captures the process for me.
This all reminds me of the three phase problem solving process I became aware of twenty years ago. At the time, I had a photographic side business which included mounting prints and cutting overmats. Phase one was six months of great frustration. I like "floating mats", where there is a thin uniform border between the edge of the photograph and the overmat. This is the method Ansel Adams described in his technical books. It is very difficult to do properly, but unmatched if done right. Most people take the expedient path and just cover up part of the image.
I purchased a top of the line C&H professional mat cutter. At the time, it cost at least twice the price of a Tormek. This was an Ansel Adams level cutter. It got me closer to what I wanted, but I was still frustrated. The frustration prepared me for phase two.
Coincidentally, I have a hobby interest in machine shop layout and technology, which has included collecting an irrational amount of machinist tools. I started aligning the forty inch long round bar on which the cutter slid. My alignment tool was a dial indicator mounted on a surface gage. I could align the bar within .001” on the dial indicator. (I realize there was an error factor, however, my accuracy was close to that.)
Using my method, my wife cut her first rectangular mat. It involved two set ups. We realized her one cut with the first set up was too short. Normally this would have meant discarding the mat and starting over. Using my method, she was able to return to the first set up with enough precision to finish the cut with the blade exactly in the kerf, no mean trick for a mat cutter.
My mounting and matting tool kit resembled a machinist tool box.
Phase two is very exciting. The brain is well tuned into the process. The results are astounding. A by product of this level of concentration is a surprisingly rapid fire pace in solving related problems. In addition to precise cutting of regular mats, I could cut fancier corner mats using the same thought process. I believe many of you have reached phase two. Reaching it was a struggle for me. My formal mathematics education ended in high school fifty years ago. My computer knowledge is essentially word processing. Sadly, I do not believe most people ever have the satisfaction of reaching phase two, or are even aware of it.
I believe many of you have reached this rare level of understanding. So many of the posts on this forum have gone so far beyond the level of how much honing compound to use. I find these developments truly amazing and satisfying.
Phase three? Dutchman has reached phase three. He developed the math solution which made this whole ball of wax possible (phase two). He also realized that this was a practical solution to a jig setting problem, not an academic exercise. The mathematical foundation is still there, and very solid, however, Dutchman has kept his focus on the practical elements.
Likewise my print mounting and mat cutting technique evolved into a much more practical level. The precision was still there, but it was in the background.
A kenjig (or a janjig, the double ended version) is easily made at essentially no cost in very little time with very little required skill. I make the standard fifteen and twenty degree angles from baltic birch plywood on my bandsaw. I often cut the basic rectangular shape on my table saw. For occasional use, cardboard cut with scissors works just as well. Are these as accurate as laboratory grade ground hardened steel or carbide Starrett inspection tools? Certainly not. I am not trying to achieve accuracy in minutes or seconds. Frankly (please, knife/math members, no fainting), I do not care if my 15° is actually a consistent 14° or 16°. I can set up a knife in a jig in almost no time. In fact, my goal is to be able to be able to sharpen an assortment of knives using a kenjig and Tormek knife jigs in a time which closely aporoximates hand held sharpening.
I do value the high level of mathematics shown by other forum members. I also value the very high level of precision Wootz has incorporated into his applet. I have it loaded on my computer. I find it invaluable for precise work. I use the applet differently than Wootz. Wootz has developed a very commendable high end sharpening business. His customers expect top notch sharpening with very neat, accurate bevels. My knife sharpening is essentially garden variety kitchen knives for my own kitchen. What is everyday high precision for Wootz is the heavy artillery I can bring in if needed for me. I am grateful to have that artillery in reserve.
This high tech work benefits the entire forum. The new user, frustrated by trying to use the Anglemaster with his knife, can make a kenjig following simple instructions in a matter of minutes out of cardboard. The only required tools are household ruler and scissors and a pencil. This will allow him to grind consistent bevels repeatably at a level of accuracy far exceeding his need. This simple tool, like the Borg collective on Star Trek, is the product of the collective, not just one mind. It began in Holland and has grown in stages all over the world.
Cyrano, I hope you will become an active member of this group.
Ken
