Thoughts on the KJ self centering jig

[Ken S]

The online class covering the KJ-45 and KJ-140 self centering knife jigs is very well done and informative. That said, I don't completely agree with everything said in the class.

Wolfgang states that while he uses the SVM in the neutral position for muscle memory, making adjustments with the height of the support bar. He notes that some users refer to adjust the jig by changing the Projection. I agree with everything to this point. He goes on to state that in the future (with the KJ-45), adjustments will exclusively be made by adjusting the height of support bar. I disagree with "exclusively".

Adjusting the height of the support bar is certainly a logical choice; however, it is not the only choice. The clamp has 13mm of holding range (15mm minus 2mm minimum). Most knives are less than 50 mm wide. A range of 0 to 60mm will easily over he waterfront. Depending on how close we are willing to skate to the edge of the limits, four to six "second edition kenjigs" will cover that same waterfront. I should note that this is for 15 degree per side bevels. I have standardized on this setting. Feel free to change to different settings if you wish. Each degree setting will probably require a separate set of kenjigs. Occasional changes of bevel angles can be accommodated with the microadjust.

Adjustments for wheel wear are really not much of a problem. Diamond wheels do not wear. The SG wears slowly with knives. Check with whatever table or app you use and consider making a new set of kenjigs when you reach what you feel is a critical wear point.

Here are a couple links:

https://www.youtube.com/live/JFHqQg5wZEg?feature=share

https://sharpeninghandbook.info/Images/Tool-Jig-KenJig.pdf

I welcome comments.

Ken

[tgbto]

Just my 2 cents :
  - There is 13mm of leeway for knives where the edge is parallel to the spine. Though I have a few such knives, many others aren't made that way (remember the advice to have the jaw of the jig parallel to the heel-tip line of the knife ?), so if you have to tilt it so the jaw is 4mm higher on one side as is quite common, that's 9mm of leeway.
  - Even with 6 kenjigs for just 12.5, 15, 17.5 and 20 degrees, that's a LOT of kenjigs. Plus if you want controlled honing with a FVB, you also need the corresponding set of jigs for the leather wheel diameter, actually one set per offset if you want to hone at +.7 and +2 dps, say. Especially if you consider making the whole set again after 10mm of wheel wear, and the switch to diamond wheels is a bit of an overkill for standard knives.

I think the beauty of the kenjig was in its simplicity and the fact that the adjustability of the SVM allowed to cover a wide range of knives. With KJs, I feel like nothing beats a calculator (/dutchman table/similar) and a simple vernier caliper. Even a mm precision is quite comfortable, and being able to get real close to the desired angle minimizes steel removal while speeding up the forming of a burr.

Last weekend, my average sharpening time for a 210mm chef knife was about 4 minutes. 10 knives in a row, office knives and wide knives, with 5 SVM-45s. There's just no way I could have done that with the KJs, as it would have required at least 4 measurements, computations, settings of both support bars.

And should I add: however well-built the yet-to-be released knife angle setting tool, it will be much harder to be consistent when you set the angle (with a roughly 1dps tool precision) by fiddling with the support bar while holding the knife. The SVM-Dutchman-caliper method is pretty much set-and-forget.

[Dutchman]

Yes, completely agree, the lack of the ability to set the projection distance with the KJ jig is significantly more time consuming and a big mistake.

[Sir Amwell]

You just know I'm going to agree with the last 2 replies.
It seems Tormek are making it difficult for sharpeners who sharpen lots of knives where time and convenience/efficiency is really important.
And it's so glaringly obvious. Ho hum.

[Ken S]

Good comments; thanks for replying. I have long asked two questions about posted thoughts: Is it possible and is it practical? With sharpening becoming increasingly sophisticated, "practicality" should be refined by asking in what circumstances (if any) is an idea practical?

I certainly agree that the kenjig works best as a one jig set up in simpler sharpening. That is how I designed it. Based on Dutchman's tables, I still believe there is nothing faster and more repeatable in the right circumstances. However, circumstances are continuing to change quickly. I have known for several years that the kenjig concept really needed some redesigning. I accidentally discovered that the single Projection length component ideally requires using SVM jigs of the longer threaded handle design. Tormek discontinued these in 2002, claiming that some users were leaning on the longer handles. I did not feel right building a concept on jigs twenty years out of production. I did not like using the SVM-00 or a second, shorter Projection length for paring knives. Both work, but not well.

The kenjig was designed "pre Wootz". Bevel angles were essentially 15° and 20°. Honing and grinding angles were the same. The FVB was not yet invented. Paper and felt wheels were not in common use, nor were superabrasive grinding wheels. Dutchman's tables were the only math game in town. Please do not misunderstand me. These developments are giant steps forward; they just were not part of the original kenjig mix.

We expect more from our Tormek jigs and accessories today. Almost all of them have been redesigned, as have the machines themselves, since I purchased my T7 in 2009. I do not believe either the SVM and KJ jigs are "the end all" jigs. They do represent the state of the art at design time. I would have preferred that the KJ jigs had Projection length adjustability. Before they were announced, I believe that the long awaited new knife jigs would probably cost at least twice the price of the KJ jigs. I suspect the design team may have felt the higher price would dampen sales, a legitimate business concern. After all, we do represent a small minority of Tormek users.

With progress, I anticipate shorter life cycles for Tormek jigs. This is because of advancement, not quality issues. The original kenjig sparked several variations from the forum. I hope this post will continue to spark conversation.

Ken

[Perra]

I do not have the same thoughts about the need for an adjustable projection length in the jig. After using my new Angel setter tool for a while now, I find it an advantage to only have one parameter to work with, Usb height, The projection length is a fixed part of the setting tool's function, after I apply the correct projection length to the tool, and the diameter of the wheels is automatically adjusted, which makes it possible to quickly adjust the usb height to the value I want "Without any knife involved during the adjustment" There the KJ-45 works very well with a fixed end support, at least for me!

I think there will be several new ways of thinking and other ways of working with quite soon. With today's possibilities with relatively cheap 3D Cad, printers and CNC machines, it is possible to quickly try out new ideas and produce prototypes in a relatively simple way. It's not just an opportunity for expensive enterprise development departments anymore. Which gives us "ordinary" users new opportunities to influence and forces manufacturers to make more effort to be at the forefront

[cbwx34]

As someone who never went the "adjust the Projection Distance" route, I don't find this an issue at all.

Personally, the new clamp and set PD is one reason I adapted a version of jvh's "Batch Calc" into the Calcapp app (the "Quick Adjust Calculator") which allows me to use the MicroAdjust to change the USB height between knives, if I do a batch (usually a block of kitchen knives)...

You cannot view this attachment.

...a bit quicker and easier than constantly measuring to the wheel or casing.  (Looks complicated, but most entries are "set it and forget it".)  Taking a PD measurement from the edge of the clamp to the edge of the knife is also quicker/easier.

I also hone freehand, which is an additional time saver.  Perra's (and maybe Tormek's) new tool may be an additional alternative... (just haven't had a chance to use one yet.)

[3D Anvil]

Hey cb, could you clarify what 1st and 2nd stop is referring to?  Because as far as I'm concerned, the KJ-45 has THREE stops.  There's the traditional back stop, of course, but then you have that middle section which can either be used pushing forward on the USB (I'd call it the front stop) or pulling back on the USB (middle stop). 

If I'm using the KJ-45 in pivot mode, I generally use the middle stop, because it provides a bigger arc than the front stop.

[cbwx34]

Hey cb, could you clarify what 1st and 2nd stop is referring to?  Because as far as I'm concerned, the KJ-45 has THREE stops.  There's the traditional back stop, of course, but then you have that middle section which can either be used pushing forward on the USB (I'd call it the front stop) or pulling back on the USB (middle stop). 

If I'm using the KJ-45 in pivot mode, I generally use the middle stop, because it provides a bigger arc than the front stop.

The front of each stop is what it's currently set for.  You can change it for how you use it... just measure and change the "Front Stop Measurement".  (Or you could measure and use the "Total Value".)

[Ken S]

CB,

I have posted before that I used the Anglemaster to set up the first chisel. It is plenty accurate. I switched to the TTS-100 for subsequent chisels because the B hole automates the Distance setting. The two metal wheels auto corrects for wheel diameter changes. Using a preset marker line for the Projection automates it. The TTS-100 automates precise set up at full speed.

Ken