a new angle setting tool

[Ken S]

Many thanks, Jan.

Your drawing is exactly what I need to clarify the setting tool. Your drawing works better than my photograph. Nice job on the excel file, too. We are getting there! By the way, the concept of using the triangle of grinding wheel, projection length and distance between the universal support an grinding wheel was never meant to be limited to knives. I actually started using it with chisels, and it will work with many tools.

Elden,

First-rate researching!

Ken

[Jan]

Ken, you are welcome! 

You are correct, the geometrical concept is universal, not limited to knives. Nevertheless your kenjig concept is assuming Tormek universal support and knife jig.

At this occasion I would like to refer to the topic "Long Knife Jig asymmetry problem", http://forum.tormek.com/index.php?topic=2577.0 . Wootz has described here, the bevel width asymmetry observed when sharpening thick knifes.

Despite the fact that in your case the jig asymmetry will not manifest itself fully, I would recommend you to use thin metal piece for your new angle setting tool. The optimal thickness of your blade is the one that has the edge in the longitudinal axis of the knife jig. In my drawing you can see that the edge is above the jig axis.

I am wondering if steel scraper would be appropriate for your tool.

Jan

[Ken S]

Interesting observation, Jan.

I have a very small scraper that I will try in the knife jig. Also, an old gift card or credit card cut to size might work well. I noticed the thicker steel edge being off axis in your drawing. Your drawing is very informative. I don't know if being off axis presents a practical problem or not. My gut feeling is that it is not a problem.

I agree that the kenjig assumes using the Tormek universal support. However, it does not assume use of the knife jig. In fact, I orininally wanted to incorporate the concept of the Tormek TTS-100 setting tool for turning tools to work with bench chisels. The TTS-100 combines the traditional spacer block and projection stop block with a very clever two points contact with the grinding wheel concept. This concept automatically compensates for changing wheel diameter. It also allows using either the T7 or T4 with no adjustment.

My grandchilren are awake. I will finish this later.

Ken

[Ken S]

Grandchildren are in school.

I originally tried using the TTS-100 with bench chisels. I like the fixed universal support ro grinding wheel and the auto diameter compensation. The rhree projection slots are all roo long. I placed a blank piece of white label tape in the shortest slot. I made marks where 20, 25' and 30 degree bevels are. Doing this once means all future chisels can be "autoset".

The present very simple design of the kenjig compromises the diameter compensation for construction simplicity. I want the average user to be able to make one with just a combination square and a handsaw.

My ideal kenjig(s) for knives would be a pair made of plastic. They would have the two contact wheels like the TTS-100. Each would have one hole, one jig calibrated and labelled fifteen degrees, the other for twenty degrees. The side opposite the contact wheels would be flat and far enough to allow for a 139 mm mark.

Ken

[Jan]

I agree that the kenjig assumes using the Tormek universal support. However, it does not assume use of the knife jig.

Ken, the assumption concerning the universal support is hidden in Dutchman formula. The figure "6" is the radius of universal support in mm. Similarly, in my formula for the corrected wheel-support distance S' there is another figure "6", which is the radius of the shaft of the knife jig, again in mm. Both assumptions are clear from my drawing.

However, if you set the bevel angle using the AngleMaster, you do not make any assumptions.

I noticed the thicker steel edge being off axis in your drawing. Your drawing is very informative. I don't know if being off axis presents a practical problem or not. My gut feeling is that it is not a problem.

Your feeling is correct!  The knife jig asymmetry problem occurs fully after flipping the knife jig. My comment was rather educative, to show that using thin blade is completely OK, while thick blade may cause some problems.

According to my preliminary estimate, the knife jig asymmetry can cause almost 1^o difference in bevel angles for 4 mm (1/6") thick knife blade. 

Jan

[Ken S]

Jan,

I believe we are operating on two different levels. You seem to be approaching the horse like an accomplished gymnist executing a precise routine. I find this commendable, and fully encourage you!

While I appreciate the solid math background, I am humbly operating on the level of one who wants to mount and dismount from the horse without falling.

My original motivation in designing the kenjig was to provide a simple, repeatable alternative to setting up the Tormek knife jigs with a minimum of tedious measuring. The jig can be used very precisely, however, it was designed to facilitate an operation which has historically been performed freehand.

Do keep up the good work, Jan. We need both levels!

Ken

[Jan]

Ken, it is always useful when two people are dealing with the same thing, although they have different approaches. 

My ideal kenjig(s) for knives would be a pair made of plastic. They would have the two contact wheels like the TTS-100. Each would have one hole, one jig calibrated and labelled fifteen degrees, the other for twenty degrees. The side opposite the contact wheels would be flat and far enough to allow for a 139 mm mark.

Ken

Your consideration of the ideal kenjig for knives, in principle similar to TTS-100, inspired me to think about how this seemingly simple tool setter works. It took me two days thinking. Hopefully, I guess how it works.

In the drawing below, you can see standard TTS-100 with additional hole for ideal kenjig for knives. The additional hole is designed for 15 degrees bevel angle and 139 mm projection length.

This TTS-100-kenjig should automatically compensate for changing wheel diameter! 

Ken, if you find it interesting, please test it on T7 and T4 and let me know. I have prepared it as a desktop exercise, without building a prototype. 

Jan

[Ken S]

Jan,

It's too bad we cannot bill Tormek consultant's fees for our thought hours; we would be more prosperous!

Your drawing is an excellent starting point; your thought time was well spent. To adapt the TTS-100 for knife work, we can eliminate the three slots (P=75mm, etc.); the three handle slots (30 degrees, etc) and the original A and B holes.

With your drawing orientation, I would place the right side against the adjustable stop as the starting reference surface for the 139mm measurement with the knife jigs. I would suggest expanding the top (of the drawing) to bottom size to incorporate the new hole and on the top to allow a little more length for the 139mm line.

Part of the beauty of this design is that it combines simplicity with accuracy and versatility. The tool can be made from a paper pattern. It could be made from one piece of cardboard or plastic. The only labelled designation necessary would be "fifteen degrees". (I would suggest having a second drawing and tool for "twenty degrees.) By using the technology of the TTS-100, the tool automatically compensates for grinding wheel wear, and also functions with full accuracy for either the T7 or T4.

The automatic compensation and utility with either T7 and T4 make this design a substantial improvement over the original kenjig for this application.

I wish to keep this tool as simple as possible. However, I would also like a third drawing with a line along the axis from the center of the hole to the contact point with the grinding wheel. I realize this would be more complicated than just a straight line. It might have to be an arc. This line would have millimeter calibration marks with every five or ten marks (short cross lines) made more bold. Each centimeter line might also be labelled. Calibration need only be within reasonable limits of the universal support distance.

The purpose of this third drawing would be to allow the user to accurately make up individualized tools for other applications. This would allow users to make jigs for specialized purposes, such as bench chisels, mortising chisels, plane blades, etc. The original template when transferred would have a sharp hole to locate the new universal support setting hole.

This project definitely benefits from having more than one mind!

Thanks, Jan.

Ken

[Ken S]

Jan,

May I modify my last drawing request?

1) I would like to incorporate a metric scale in the middle, perhaps three to five centimeters. This would allow me to check the printouts with my metric rule and insure they are printed to the proper scale.

2) One drawing with cross hairs for both fifteen and twenty degree bevel circle locations is fine. I plan to print out your drawing, cut it out and use it as a template for 3mm or 6mm thick baltic birch plywood. I can use the cross hairs to accurately locate the holes with a sharp pointed divider leg.

3) Could you please include the location of the hole for eighteen degrees? Steve Bottorff uses eighteen degrees for the primary knife been he uses with the Tormek. Being able to set that quickly would be useful.

4) After further thought, please leave in the two original holes of the TTS-100. I am thinking beyond knives for this. I have found the existing holes useful for bench chisels and plane irons. My thinking would be to use the jig in reverse for them: set the distance between the universal support and grinding wheel first using the existing holes. Set the projection length of the tool to conform to these, and mark the back side of the jig with this distance. This individual setting would be instead of the "139mm" mark.

An example of this might be, using the nearer hole (designated A on the TTS-100) with a mortise chisel, then determine the correct tool projection length using either a black marker or the angle master. Scribe this distance on the jig. Label the jim "Mortise chisel, thirty five degrees". (This is just an example.) This baltic birch jig would be custom made for mortise chisels and reserved for their use. I do not want to limit this jig to knives.

I do appreciate your help with this, Jan.

Ken

[Jan]

Ken, your interest really pleases me. 
Now I need a little rest, the thinking made me tired, plus I am still reconsidering some methodological aspects. I cannot rule out a minor corrections.

I have assumed that you have the TTS-100, and that the additional hole you can easy realize by screwing two small plastic plates, through the A and B holes, to the sides of the original tool setter. For this purpose, the dimensions given in my sketch are fully sufficient.

To your questions:
Ad1) In the posted drawing they are three protrusion lengths (75, 65, 55 mm), which you can use (75, 65, 55 mm) for scaling.

Ad2) I am afraid that you will not be able to build the tool from plywood with sufficient accuracy. In doing a dozen of sketches I saw that an accuracy of 0.5 mm is not sufficient. I intend to purchase the TTS-100.
I will add the hole for 20 degree later, when I am quite sure that the prototype for 15 degrees works fine.

Ad3) We will see the positions of the additional holes for 18 and 20 degrees, they can overlap.

Ad4) Thinking beyond knives is nice, but my additional holes assume the knife jig!

Jan

[Ken S]

Jan, for after your rest:

I have been working with your drawing. No need for the metric scale. I do have a TTS-100. It was one of the first accessories I purchased, and I really like it. I placed my printout of your drawing on a flat surface and matched the existing A and B holes of the TTS-100 with your drawing. The scale was close, but not exact. By trial and error I reprinted your drawing with the page setting set for 103%. It was an exact match. (I'm sure the error factor was in my printer.)

You are correct; the three projection slot lengths show the same 103% correction is necessary. i can easily pencil in the extra size needed to accommodate the fifteen and twenty degree holes. I have a piece of 6mm baltic birch plywood large enough for two tools. I prefer not to have the holes overlap, so the first tool I make will be for fifteen degrees. That happens to match my existing kenjig.

I agree with you that plywood, even baltic birch, is not the ideal material for an accurate tool. The ideal tool would be a slightly modified Tormek made TTS-100 (Are you reading this, Sweden?) As the tool would be used for Knife Setting rather than Turning Tool Setting, I would suggest a Tormek product name of KS-100.

The Tormek TTS-100 is a very superior product. In my opinion, it is the most accurate and versatile Tormek layout tool by a wide margin.The two contact wheels are metal. There are two wheels on each side of the tool, much like the four wheels on a car. The wheels spin when contacting the grinding wheel when the grinding wheel is moved by hand. The tool is improved (in my opinion) by drawing lines from the center of the wheel to one point along the circumference. This resembles a bicycle wheel with one visible spoke and makes it very easy to see when the wheel first makes contact.

The two wheel axles snap in place. the tool is nicely made with a raised circle in the plastic for good wheel clearance (nice touch, Tormek). As I recall, I first saw these spoke lines in the Tormek Friends Glenn Lucas video. Good tip, Glenn.

With the projection slots facing up, the back side of the tool has a registration shoulder surface to hold the tool in place against the edge of a work bench. This is a good design feature for turning tools. As a more advanced prototype, I would acquire at least one more TTS-100. i would grind or sand off the back projection shoulder to glue on a piece of flat 3mm plastic. By using Jan's template and accurately laying out the new fifteen degree hole and both of the existing holes, aligning the two existing holes with the TTS-100 will assure accurate alignment for the new hole.

With the plastic plate accurate in place and secure, I would draw the 139mm line opposite the flat edge (the former edge with the three projection slots).

My first choice would be to eventually purchase a Tormek made version of this, should Sweden decide to make one.

Ken

ps (later)

If, instead of the humble resources of my home workshop, I had the power of the Tormek engineering department, I might be tempted to make my jig a realistic copy of the TTS-100 with the single hole modified to resemble the angle adjustment of the WM-200. That way, one accessory would cover both fifteen and twenty degrees, with intermediate settings included. Like both the TTS-100 and thr WM-200, the KS-100 would be equally at home with both the T7 and the T4. The TTS-100 presently sells for $27.00 US. As most of the design is already completed, the KS-100 should sell for around the same price.

[Jan]

Ken, I'm glad you have the TTS-100, and you are ready to build a physical prototype. 

TTS-100 is for testing of our prototype, with additional knife holes, the best solution. TTS is not easy to make in a home workshop with limited, humble resources.

TTS-100 simply bewitched me, I could not stop thinking about it until I understood how it works. 

For your testing you can download a high resolution image of my TTS-100-kenjig drawing from the following address: https://www.dropbox.com/s/nm61j0qss6lmpes/TTS100_3.jpg?dl=1

Please keep in mind, we are testing prototype and I cannot rule out some minor hole position correction for improving the function. It should work for wheel diameters from 250 mm to 160 mm!

Jan

[Ken S]

 Jan, you make a good point about the importance of physical prototypes. I once spent a lot of time designing a new jig to make duplicate threading patterns on a Unimat lathe. The extensive pencil designing work in my graph paper notebook evaporated when I finally started to make a physical prototype. (The motor occupied the same physical space!)

The present simple wooden kenjig is actually the product of several more primitive prototypes. The present jenjis is joining the ranks of prior prototypes. That's progress. Let's stay tuned and see where this progress leads. Other forum members: your ideas are most welcome.Join in the fun!

Ken

[Jan]

Ken, during your Hartville programme, I have improved my drawing SW portfolio, so I could drop my hand sketching. 

In the drawing below you can see, in red, the length L and height H which we need to position the additional hole in the TTS-100.

High resolution drawing at actual size, which can serve as a drilling template, can be downloaded from the following address:
https://www.dropbox.com/s/qw32tgvsaacd2k2/TTS100_7_skut_vel.pdf?dl=1

Jan

P.S.: Hats off, Tormek, the concept of TTS-100 is uniquely simple and effective.

[Ken S]

Jan,

Driving to  the Hartville job, I had an idea. Using the two point contact of the TTS-100, if we draw a circle of say 250mm diameter, like a new Tormek wheel; and place the cut out circle touching the two points. Using the center point of that now attached circle as the starting point with a compass and the center point of one of the existing holes ("A" and "B") as the pencil point for the compass. If we draw an arc, will that arc be equidistant from the center point of the grinding wheel circle? (sorry for the very complicated sentence)

If that arc yields a constant distance from the center point, can we do the same thing with your angle points? If those arcs are equidistant from the center, we should be able to locate the 12mm (slightly larger for clearance) holes anywhere along the arc. That way we can avoid the overlapping holes or enlarging the existing jig.

Measuring from the outside lip of the side of the jig with the three projections slots (55, 65, 75mm), the length to the far side, by the one contact wheel is just over 139mm. If all this works, all we would need to do to have a very workable (but somewhat crude) prototype is scribe a line at 139mm , locate and drill the angle holes we wish. Label the holes, and the jig is done.

This simple jig would not only work with turning tools (as originally designed), it would also work for kitchen knives. I also have mine set up for bench chisels and plane blades.

In my opinion, using a single jig for all of this would be confusing for many users. I would prefer a separate jig for kitchen knives, bench chisels and plane blades (essentially for kitchen knives and straight edge tools). Modification on a "homemade" level could easily be done in a home workshop in an hour (working slowly). On a more professional level, Tormek would already have most of the engineering completed in the original TTS-100 design. Retooling for the knife/ straight edge bevels jig should be inexpensive.

I wish I had a better math background. I am grateful that you do, Jan, and do appreciate your good work!

Ken