chisel set up

[Ken S]

I spent part of yesterday working with my sharpening chisels. I have five Irwin Blue Chip 3/4" chisels and three other sizes. They are efficient tools for learning and testing.

Yesterday I was comparing two CBN wheels and the SG-200. I also continued my project of comparing Tormek Honing Compound and valve grinding compound. As part of the testing, I made BESS edge sharpness readings and photographs.

All of the bevel angles were 25°. I was using three Tormeks, three grinding wheels and three leather honing wheels. Set up was accurate, fast and repeatable. I used only Tormek's most advanced set up tool, the TTS-100. I use the closer hole on the jig, the one normally used for spindle gouges as my standard Distance for chisels. I set the chisel protrusion from the square edge jig by using a two step process. The first step is by eye. I then do step two, which is checking this eyeball setting with the piece of label tape I placed in the 55mm protrusion slot of the TTS-100 and marked with several angles. (I used the Anglemaster for this initial set only.) With care, my eyeball settings have all been closer than 2 or 3mm of the mark.

This procedure produces consistent bevel angles very quickly. It is uneffected by changes in wheel diameter. It was also my original prototype for the kenjig.

Ken

[Ken S]

I should add that my applying the TTS-100 to chisels is not a new discovery. These techniques all go back to Torgny Jansson and the handbook. The connection may not be identical, but the fundamentals begin with the handbook.

Ken

[Jan]

Ken, it is an interesting issue. Can you be more specific and let us know where we can find the text you are referring too?

In my understanding the TTS-100 was designed to work in conjunction with the gauge jig and the multi jig and not with the square edge jig or some other jigs. 

You have probably invented an auxiliary usage of the TTS-100 in conjunction with the square edge jig which enables approximate chisel edge angle setting for stones of similar diameters. For me it is beyond the intended TTS-100 design however a nice example of unconventional thinking. 

Jan, an admirer of the TTS-100

[Ken S]

Jan,
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The part of the TTS-100 relating to setting the distance between the universal support bar and the grinding wheel goes back to when a block of wood was placed between the support bar and the grinding wheel. Jeff Farris describes this very well in the DVD included with the woodturner's information kit. I gather this was standard operating procedure before the TTS-100.

Jeff also showed using a simple homemade wooden stop block to set the protrusion for a gouge which did not fit the standard profiles of the TTS-100. I have not found a direct reference to the wooden stop block. The protrusion slots of the TTS-100 seem like an offspring of the stop block.

I still do not understand how the TTS-100 can compensate for wheel diameter changes with skew  chisels and gouges and not bench chisels. I'm not stubborn, just confused.

Ken

[SharpenADullWitt]

So you don't know where you saw that in the manual?  (wondering if it was an older manual, or if it would be in the current one)

I don't doubt that Torgny died with idea's still up his sleeve.  I could see a non turners version, being something he was going to make.

[Jan]

Ken, the cornerstone feature of the TTS is the fact that a line jointing the centres of the metal discs is parallel with a tangent to the stone at a point where the edge meets the stone. This property is not dependent on the stone diameter.

Tangent is a line of fundamental importance for any grinding because it defines the edge angle. See e.g. Steve Bottorff video about freehand knife sharpening on the Tormek   https://youtu.be/bWJsyHoFc5I
Steve shows here how simple it is to sharpen a primary bevel angle of 18° (edge angle is 36°). He holds the blade horizontally and meets the stone 18° below top dead centre position. See the attached picture, where the tangent is shown in red.

The position of the USB hole in the TTS is given by jig geometry, the desired edge angle and the tool protrusion. The position of the USB hole is defined relative to the tangent line mentioned above. Because geometrical characteristics of jigs are different the TTS has to be designed individually for a specific jig. They are some exceptions from this rule (e.g. the gauge jig and the multi jig).

In my understanding Tormek does not offer a tool setter for the square edge jig because the edge angle setting is quite simple in this case. 

Jan

[Ken S]

SADW,

One of my researching frustrations is not having access to the earliest handbook editions. If anyone has a very early (pre-yellow) edition and would scan it for me, I would be most grateful. Some of the earliest techniques have become mostly forgotten with the advent of newer jigs. In the cases of stop and spacer blocks, I believe these older techniques still have applications. It is regrettable that we do not have a published version of Torgny's idea book.

One case of an idea which was once a glorious failure is my thought to use Robin Bailey's extended support bar across the top of the Tormek to provide a horizontal position for grinding into the wheel. This runs counter to Tormek's wise limitation to prevent some bozo from accidentally turning into the leather honing wheel. I understand this. The glorious failure was watching water cascade all over the table flowing over the tool and everywhere.

This failure became a success using a dry CBN wheel with the Tormek. It gives the control of the lower grinding position with the speed of the into the tool direction of the vertical position. It does not work with the square edge jigs, however, it works very well with turning gouges.

Jan,

I agree that the setting up of a square edge jig is generally more simple than many other jigs.Both the black marker and the Anglemaster work well with chisels and plane blades.I just think my modified TTS-100 or gage block system works better and faster. I no not have to measure. I just slide the support bar into the inner hole of the TTS-100 and the Distance between the universal support bar and the grinding wheel is consistent.

I have trained my eye to allow me ro set the Protrusion of the chisel from the jig by eye. My settings, which I always verify with the gage mark, are by eye alone within plus or minus about two millimeters. This bypasses gross adjustments.

Where this system really shines is with multiple tools. It eliminates almost all lost time during set up and is consistent. Sharpening chisels for a school would be no problem.

I think the TTS-100 is Tormek's best set up tool. I just wish Tormek would expand this fine idea to encompass other tools, including various square edge tools, knives, and carving tools.

Ken