NEWS! Two new knife jigs!

[Ken S]

Good points, Rick and CB.

We will all know more when we actually have the new jigs in hand and can measure them.

For a long time, I believed that I had come upon the 139mm Projection independently. I spent a long time during the early development of the kenjig measuring Projections. 139mm is in the middle range of the SVM jig adjustment threads. At the time, I did not realize that Dutchman (Ton Nillisen) had included these Projection measurements in the 2013 grinding angle booklets he had posted on the forum. Ton's work is the basis for my kenjig, as well as the other computer knife set up computer apps which have followed.

I look forward to adapting the kenjig concept to the new jigs. Two fixed jig Projection points will be different than the present adjustable shaft. It may actually prove to be simpler to use. I designed the kenjig to work with three preset jigs for fifferent widths of knives. This systen can be very fast, usually requiring no jig or support bar adjustments with different knives.

I am curious to see how the fixed Projection jigs will work. They may actually be faster to use. I am certain the clever minds of the members who designed and built things like the pivot points for the SVM jigs will be just as clever with the new KJ jigs.

Ken.

[Sharpco]

I'm not convinced about the convex ability, but what I see (maybe) is a built in "pin pivot" collar.

IMHO, the space is too narrow for "pin pivot". So I think we have to use both SVM and KJ.

[cbwx34]

I'm not convinced about the convex ability, but what I see (maybe) is a built in "pin pivot" collar.

IMHO, the space is too narrow for "pin pivot". So I think we have to use both SVM and KJ.

Yeah... probably wishful thinking.

They worked hard to "design out" pivoting.      

[Ken S]

Gentlemen,

I suggest we table this debate until we all have a chance to actually use the new jigs. Also, I would be surprised of Tormek did not have an online class on them within a month or so.

Ken

[Sharpco]

Yeah... probably wishful thinking.

They worked hard to "design out" pivoting.      

I agree. But if the extra stop's position was a little higher, a freer pivot would have been possible.

[jeffs55]

If self centering means that you will be able to grind an equal bevel on both sides of a blade, wow! That is my only complaint against the Tormek was the uneven grind. All I use one for is knives and then I pretty much stopped that and chisels.

[Ken S]

Jeff,

From my limited information, I believe you will be pleased with the new knife jigs. Tormek usually spends at least of in house testing before releasing new products. I gather that these knife jigs have received more extensive than usual testing. Tormek has absorbed a lot of grumbling because the present SVM jigs are not self centering. I expect quality
jigs and that Tormek will produce a thorough online class style video sometime in early spring.

Ken

[tgbto]

I've tried to estimate what the impact of this dual-stop configuration would be on the actual apex angle. Eyeballing the gap in the video, i'd say there's a 12 to 15mm gap between the outside edge of the usb when in the "standard" position, and the top of the bottom stop.

If this is true, and if I got my math right, that would mean a 7 to 10 dps difference in apex angle compared to the shoulder angle. It's a huge difference, don't you think ?

If I'm correct in saying that the apex angle matters more than the shoulder angle, then it means we'll have to set our angles for the position where the usb is against the lower stop, and be sure to grind consistently in this position. That is, pulling the jig, which seems a bit awkward after having spent so much time saying that resting the palm on top of the SVM is key to stability and consistency.

In addition, what we see in the video is mostly done with the USB against the top (standard) stop. I fail to see how you'd set up your jig using the sharpie method (or a calculator or the infamous AngleMaster) against the top stop, then decide to offset it here and there by 8 degrees.

I was afraid this new jig would have me put away my 5 SVM-45s, but given how small the actual concavity of the grind is, my initial estimate is that I'll use one of these for very thick of very thin knives and use my SVM-45s for the rest, probably with the pin-pivot collar.

[tgbto]

And another question that comes to mind: if I stop the video @0:18, where the sharpener is feeling for the burr, I see the gap between the jaws somewhat tighter at the handle side than it is at the blade side. And also the jaws seem to contact the very spine of the blade, much like today's SVM-45s.

For a self-centering jig to be efficient, I would expect it to be flat against the sides of the blade, and somehow wider in the middle, around the black plastic screw, so that it then pinches the blade and holds it in place. Else the jaws might be centered but the blade offset to be flat against one jaw or the other.

What do you think ?

[cbwx34]

I've tried to estimate what the impact of this dual-stop configuration would be on the actual apex angle. Eyeballing the gap in the video, i'd say there's a 12 to 15mm gap between the outside edge of the usb when in the "standard" position, and the top of the bottom stop.

If this is true, and if I got my math right, that would mean a 7 to 10 dps difference in apex angle compared to the shoulder angle. It's a huge difference, don't you think ?

If I'm correct in saying that the apex angle matters more than the shoulder angle, then it means we'll have to set our angles for the position where the usb is against the lower stop, and be sure to grind consistently in this position. That is, pulling the jig, which seems a bit awkward after having spent so much time saying that resting the palm on top of the SVM is key to stability and consistency.
...

Probably a "wait and see" answer here... will be curious to see how Tormek demos creating a convex edge.  I suspect it will be for just a few style knives (like maybe a cleaver?)

And another question that comes to mind: if I stop the video @0:18, where the sharpener is feeling for the burr, I see the gap between the jaws somewhat tighter at the handle side than it is at the blade side. And also the jaws seem to contact the very spine of the blade, much like today's SVM-45s.

For a self-centering jig to be efficient, I would expect it to be flat against the sides of the blade, and somehow wider in the middle, around the black plastic screw, so that it then pinches the blade and holds it in place. Else the jaws might be centered but the blade offset to be flat against one jaw or the other.

What do you think ?

I wouldn't put much stock in a "demo" video... just like the standard jig, I would think the gap can be adjusted.  Like I mentioned earlier, clamping tapered blades is one of the stated features.

[RickKrung]

And another question that comes to mind: if I stop the video @0:18, where the sharpener is feeling for the burr, I see the gap between the jaws somewhat tighter at the handle side than it is at the blade side. And also the jaws seem to contact the very spine of the blade, much like today's SVM-45s.

For a self-centering jig to be efficient, I would expect it to be flat against the sides of the blade, and somehow wider in the middle, around the black plastic screw, so that it then pinches the blade and holds it in place. Else the jaws might be centered but the blade offset to be flat against one jaw or the other.

What do you think ?

I'm with Ken and CB, I think we just have to wait and see about all these speculations when we get out hands on these new jigs. 

As for your question about the gap, I think you are correct and the Tormek manual describes the need to adjust the screws so the jaws grip the knife spine/blade so they are in contact all along it.  As CB says, I think it would be hard to judge from a video.  And I am like you, not going to set aside all my current jigs and go out and replace them with this new one.  For one thing, I have made the Knife Grinders modifications of relieving the jaw faces on three of mine, two at 0.5mm and one at 1.0mm and use shims to center the blades, so I don't know that I'll be getting one of these new ones very quickly. 

Rick

[tgbto]

Probably a "wait and see" answer here... will be curious to see how Tormek demos creating a convex edge.  I suspect it will be for just a few style knives (like maybe a cleaver?)

Sure, but hey... what's the fun in announcing stuff early if we can't speculate

That being said, I think the only time I nicked a stone was when I didn't keep the jig in place by pressing it firmly against the USB. That seems to be a case for edge-trailing sharpening using the USB. Did anyone say FVB ^^ ?

[Ken S]

Sure, but hey... what's the fun in announcing stuff early if we can't speculate "

I think that may be the real crux of the problem; the jigs were announced before both availability and, especially, before a proper online class.

Ken

[Ken S]

Some misc. thoughts:

Like Rick (and several others), I have standardized on 139mm projection. It works well most of the time (except for paring knives) with the SVM-45 jig. I suspect I may have to recalibrate with the new KJ-45 jig. Having two stops may actually work out better with paring knives. As Rick stated, recalibrating is no big deal.

Looking at the jig instructions, I don't think aligning the jig surfaces to match a blade taper will be a problem. I agree with CB on this.  It's too bad if this does not show clearly on the short video. Hopefully, a more in-depth video will clarify this.

Like Projection, a pivot point jig, while useful, is not part of Tormek's technique. All of the online classes showing knife sharpening include sharpening a skinning knife with a sharp curve in the blade shape. I suspect the longer video for the KJ-45 will also include a skinning knife.

Looking into my crystal ball, I predict that those of us who purchase a KJ-45 will probably use it most of the time. I have the early SVH-60 square edge jig in case I ever have to sharpen a thick "pig sticker" mortise chisel. To date, I have never used it. I have my old SVD-185 gouge jig, modified with Rich Colvin's rotary cutter jig parts. I will keep my seven present knife jigs, just is case, although I doubt they will see much service.

Ken

[Dutchman]

Some misc. thoughts:
...
I suspect the longer video for the KJ-45 will also include a skinning knife.

Looking into my crystal ball, I predict that ...

I predict that the 'long video' will present a new method for setting the grinding angle