Tilted collar of knife jig

[Sharpco]

https://forum.tormek.com/index.php?topic=3493.0

I found a reason for the above problem. It was a tilted collar.(Rotating the collar doesn't solve the it) I have two SVM-45, but all have this problem.

Have you ever been discussed about this issue before?

Is there a way I can solve it myself?

[Stickan]

Hi,
Looking at your pictures I see that the knife is not mounted correct in the jig. Instead of having pressure in the opening of the jaws, the knife is locked into place in the jig and that will not lock the knife properly. So the Square in the picture is where you have locked the knife into place and it should be clamped so the jaws are in contact with the blade in front, the cirkle in the picture.
When the knife is mounted in the jig like your pictures, the blade is twisted in the jig which causes your problem.

Sincerely,
Stig

[Ken S]

Sharpco,

I am pleased that Stig (Stickan) replied. I have known Stig for several years, and am continually impressed with how much Tormek knowledge he has, especially with knives. His knowledge combines his personal fascination with knives and sharpening; access to resources and coworkers with Tormek's over forty years of experience; and a wealth of information from working with knife experts throughout the world.

One of the reasons I believe in work methods which standardize parts of the operation, like the kenjig or Wootz' KnifeGrinders computer program, is that the time saved allows us to spend more time on other parts, like aligning the knife in the jig, and remain within the same total time. By automating setting the bevel angle, our minds are free to concentrate more fully on things like jig alignment and the actual grinding.

May I offer two minor constructive suggestions on your photographs in this topic? First, the part where the knife is clamped into the jig is very dark. Using a white piece of paper as a reflector might put some light into that area, making it more easily seen. Another idea would be to use a light source such as a work light or flashlight. You don't need much light, just enough to raise the level from dark gray to middle gray. If the light is too bright, moving it further away will help balance it. Or, if the light source is cool, like an LED light, placing a paper towel or handkerchief over it will lessen it.

Second, your point of sharp focus is too close. if you are using a close up mode on your camera, the default focus point is often the closest area. In this case, that is the etching on your knife. Switching to a focusing option which allows you to use a single point aimed where you want it will correct this.

Metal is difficult to photograph. Your questions are well chosen and deserve photos which are on the same level.

Good topic. Keep up the good work.

Ken

[Sharpco]

Hi,
Looking at your pictures I see that the knife is not mounted correct in the jig. Instead of having pressure in the opening of the jaws, the knife is locked into place in the jig and that will not lock the knife properly. So the Square in the picture is where you have locked the knife into place and it should be clamped so the jaws are in contact with the blade in front, the cirkle in the picture.
When the knife is mounted in the jig like your pictures, the blade is twisted in the jig which causes your problem.

Sincerely,
Stig

I did what you said, and the difference became worse.

BTW, is it intentional for the tilt of the collar?

[Sharpco]

Sharpco,

I am pleased that Stig (Stickan) replied. I have known Stig for several years, and am continually impressed with how much Tormek knowledge he has, especially with knives. His knowledge combines his personal fascination with knives and sharpening; access to resources and coworkers with Tormek's over forty years of experience; and a wealth of information from working with knife experts throughout the world.

One of the reasons I believe in work methods which standardize parts of the operation, like the kenjig or Wootz' KnifeGrinders computer program, is that the time saved allows us to spend more time on other parts, like aligning the knife in the jig, and remain within the same total time. By automating setting the bevel angle, our minds are free to concentrate more fully on things like jig alignment and the actual grinding.

May I offer two minor constructive suggestions on your photographs in this topic? First, the part where the knife is clamped into the jig is very dark. Using a white piece of paper as a reflector might put some light into that area, making it more easily seen. Another idea would be to use a light source such as a work light or flashlight. You don't need much light, just enough to raise the level from dark gray to middle gray. If the light is too bright, moving it further away will help balance it. Or, if the light source is cool, like an LED light, placing a paper towel or handkerchief over it will lessen it.

Second, your point of sharp focus is too close. if you are using a close up mode on your camera, the default focus point is often the closest area. In this case, that is the etching on your knife. Switching to a focusing option which allows you to use a single point aimed where you want it will correct this.

Metal is difficult to photograph. Your questions are well chosen and deserve photos which are on the same level.

Good topic. Keep up the good work.

Ken

Thank you, Ken. I'll remember it.

[Stickan]

Hi,
Try again, but further back on the blade and with less pressure on the black knob.
Also check if the blade if perfectly flat.

Best,
Stig

[Sharpco]

Hi,
Try again, but further back on the blade and with less pressure on the black knob.
Also check if the blade if perfectly flat.

Best,
Stig

If I reduce the pressure of the black knob, the jig will miss the blade. BTW, I jigged a bit further behind the blade but the problem is not solved.


Is this a problem because I don't know how to use the jig? (But I think I have enough understanding of the manual)

Or is the jig's design wrong? I guess not.  Because this problem has never been discussed in the forums before.

Or is my 2 jigs all defective? Hmm... I'm very confusing.

[cbwx34]

If the blade tapers from spine to edge, it needs to be centered in the clamp, and the gap that Stickan is referencing, might be the reason... and the reason it gets "worse" when you try and correct it.

I'm curious though, what you reference was for your third picture.  I checked mine using a square referenced against the side and back of the jig, and didn't see a gap...



... you might consider rechecking this.  I would also clamp a blade flat on the sides and see what you get, (if the blade in your photos does taper, it introduces a factor you need to first eliminate to solve this).

[RickKrung]

I found a reason for the above problem. It was a tilted collar.(Rotating the collar doesn't solve the it) I have two SVM-45, but all have this problem.

Have you ever been discussed about this issue before?

Is there a way I can solve it myself?

The SVM-45 knife jig shaft is nomially 12mm.  Mine measures 11.95-11.98mm.  The diameter of the hole in the adjustable collar measures 3x 12.45 - 12.47, the fourth 12.57mm.  Of course there will some rocking, but I don't see how that will substantively affect your bevel.  It is worse the higher up the shaft the collar is located (see the four photos showing the tilt)

If you are really concerned about it, wrap some masking tape around the shaft to build it up near the front of the collar, but keep it inside the collar so as to not ride on the USB and potentially changing your bevel angle (tape is shown showing for the picture).  It took three wraps of blue painters tape to increase the diameter of the shaft on my jig to 12.55mm and there is no rocking at all. 



Rick

[cbwx34]

The SVM-45 knife jig shaft is nomially 12mm.  Mine measures 11.95-11.98mm.  The diameter of the hole in the adjustable collar measures 3x 12.45 - 12.47, the fourth 12.57mm.  Of course there will some rocking, but I don't see how that will substantively affect your bevel.  It is worse the higher up the shaft the collar is located (see the four photos showing the tilt)

Is your O-ring present?  Mine won't tilt without some pressure, more than you'd get in sharpening... the O-ring "pushes back".

(Same question to Sharpco... O-ring still there)?

[RickKrung]

Is your O-ring present?  Mine won't tilt without some pressure, more than you'd get in sharpening... the O-ring "pushes back".

(Same question to Sharpco... O-ring still there)?

Yes, 'tis.  Yes, without th O-ring it is crazy wobbly. 

Rick

[Sharpco]

If the blade tapers from spine to edge, it needs to be centered in the clamp, and the gap that Stickan is referencing, might be the reason... and the reason it gets "worse" when you try and correct it.

I'm curious though, what you reference was for your third picture.  I checked mine using a square referenced against the side and back of the jig, and didn't see a gap...

... you might consider rechecking this.  I would also clamp a blade flat on the sides and see what you get, (if the blade in your photos does taper, it introduces a factor you need to first eliminate to solve this).

I tried the same with other knives. The other knife showed little difference, but the problem was not completely solved. I have tried many ways to tighten the two knobs in the jig, but I am still having problems.(If the jig is normal and I have misused it, why does not the manual provide guidance?)

And I don't seem to need a reference to my problem. Because the tilt of the collar is easily identified by the eye.

I totally agree with your opinion that tormek should redesign the knife jig.

[Sharpco]

The SVM-45 knife jig shaft is nomially 12mm.  Mine measures 11.95-11.98mm.  The diameter of the hole in the adjustable collar measures 3x 12.45 - 12.47, the fourth 12.57mm.  Of course there will some rocking, but I don't see how that will substantively affect your bevel.  It is worse the higher up the shaft the collar is located (see the four photos showing the tilt)

If you are really concerned about it, wrap some masking tape around the shaft to build it up near the front of the collar, but keep it inside the collar so as to not ride on the USB and potentially changing your bevel angle (tape is shown showing for the picture).  It took three wraps of blue painters tape to increase the diameter of the shaft on my jig to 12.55mm and there is no rocking at all. 



Rick

My jig is not rocking as much as you showed. But I think that it is not a big problem even if it rocks because it will still sharpen the knife symmetrically.

[Sharpco]

Is your O-ring present?  Mine won't tilt without some pressure, more than you'd get in sharpening... the O-ring "pushes back".

(Same question to Sharpco... O-ring still there)?

My O-ring is being there. 

[cbwx34]

I would try Rick's tape idea... maybe it will "force" the collar to line up with the jig.