Messages

Wootz, yes, I concur with your estimation of the offset of your polished jig as being 1.3mm.  I recall someone saying they were concerned about the jigs causing scratches on their customer's knives.  Is that the reason for polishing the jigs?

Jan, yes, I do assume it is parallel, but as I've said, "trust but verify".  I did look at it.  I held a straight edge on the flat and examined how it lined up with the parting line on the shaft.  It appeared very much parallel. I also examined how "flat and parallel" the surface of the flat appeared and it did appear that way.  If it wasn't, all those fancy measurements would not have meant much. 

And thanks, both for your thanks.  Why to I do to such extremes?  It is like dogs...  Why to dogs lick their ...   Because they can... 

Rick

Rick, your interest pleases me! 
It is an inexpensive and very versatile adaptor.

Jan

I have previously measured the spacing between the USB holes, and came up with 90mm also... so can at least confirm that.

Thanks to both of you for the info... I'll be building one... as soon as the parts come in.   

My implementation of Jan's extension jig is shown below.  I already had the XB-100 Horizontal Base and the 1"x2"x1/8" thick steel tubing, so I was able to get this far.  While I measured and posted the Base hole mount dimensions, I opted to clamp the base to the tube and spot drill the hole locations.  I tried clamping it square but something didn't work out and the jig was not square once mounted, so I opened up the jig holes and now it does. 

I also precision clamped the Base to the backside and spot drilled the first 12mm hole and then center drilled it.  Then took out the layout blue and tools and carefully layed out and center punched the location of the second 12mm hole.  Existing USBs slide in just fine. 

I used to live in Portland, OR, USA (a medium sized city) and could just run out and get things like M12-1.5 threaded rod and nuts.  But, a little over a year ago, I move to a tiny town in far NE Oregon with a population of 300, but it is in ranching country so it has two hardware stores.  Still, I had to order the threaded rod and nuts.  Will have to wait for them to finish the project. 

Rick

The threaded rod and nuts arrived today, so I completed my entry. I was easily able to obtain M12 x 1.5 threaded rod in plain steel, but it cost a fortune (>$300 US) for it in stainless steel.  So, I opted for M123 x 1.75 which was way less expensive ($34).  Seems to me like it won't matter that much.

I made the bars 8" long.  Not sure that I'll ever need them that long, but I had a meter of threaded rod.

Rick

I, for one, would like to know how to post an image so that it shows full size rather than a thumbnail that must be clicked on to view effectively. 
Rick

I missed the 2nd part of your request.  If you don't want to use a 3rd party host, you can insert the images you attach to a Tormek post.  You just have to modify your post, after you post it.

When you attach a picture and create a post, you'll notice that it creates a link.  Copy this link.  Then click on "Modify" for your post.  Put the cursor in the location where you want to place the picture, then click on "Insert Image", and paste the link you copied earlier.

If you do it this way, you are restricted to the Tormek size limits, (and have to be logged in to see the pictures, just like you do for the attachment), but now your pictures appear in the post, and don't have to be clicked on to view.

Thanks, CB.  I'll give it a whirl. 

Rick

Rick, attached there is an image of the static knife jig clamp. The surface is not planar. One feature is the threshold denoted C. Other features are the two very slightly raised strips denoted as A and B. The area D between those stripes is below the level of the point E! (I am describing a new zinc jig.)

What we really need is to measure the spacing between the centreline of the jig shaft (at a place where there is the jig stop, not at a point E) and the slightly raised strip A or B near the bottom of the knife clamp.

To make such measurements reliably and repeatedly was beyond my limited possibilities and that was the reason for my adoption of the spacing 1.25 mm.

Jan

I can appreciate that.  I do have the ability to measure accurately, so here is what I found.

I measured the height of the several points on the flat side of the fixed jig jaw using a precision height gauge that reads at 0.001".  I placed the jig on its back side on parallels on a precision granite surface plate.  First, I stoned the parallels and measured them.  They were about 0.0005" different, the narrower one was placed under the front of the jig jaw (on the right in the photos). 

Zooming in on the height gauge in the photos below and referring to Jan's location callouts, point E measured 0.499" ("zero" on the gauge is the center of the set screw hole, which would be 0.500" in this case).  The height gauge could not reach point C, so I measured a point about equa-distant between point E and A, measured 0.499".  Point A measured 0.498".  Point D measured 0.4895", but I'll call it 0.490", about 0.008" - 0.009" lower than E, E-A and A.

I further checked the recess (area "D") with a feeler gauge - 0.010" went in, but 0.011" did not. 

I also measured seven locations of the flat with my micrometer (Mitutoyo, reads to 0.00005" with an uncertainty of measurement of 0.000044", according to the Certificate of Inspection)  The values ranged from 0.35185" to 0.35245".  Point E was 0.35145", Locations E-A and E-B were 0.35220". Rounding to the nearest 0.0001" there is a range of 0.0007" difference of the flat surface.  Pretty dang good for a casting and every single one will be different.  We can all come to our own conclusion on where to measure the thickness while attempting to determine the magnitude of the offset. 

Rick

Correctness of my value 1.25 mm was not confirmed by Tormek.

Jan

It would be most helpful if Tormek would chime in here with their design offset values, rather than us trying to reverse engineer them.

Rick

Rick, attached there is an image of the static knife jig clamp. The surface is not planar. One feature is the threshold denoted C. Other features are the two very slightly raised strips denoted as A and B. The area D between those stripes is below the level of the point E! (I am describing a new zinc jig.)

What we really need is to measure the spacing between the centreline of the jig shaft (at a place where there is the jig stop, not at a point E) and the slightly raised strip A or B near the bottom of the knife clamp.

To make such measurements reliably and repeatedly was beyond my limited possibilities and that was the reason for my adoption of the spacing 1.25 mm.

Jan

Jan,

I agree, mostly.  Using a straight-edge, it appears to me that points A and B are on the same plane as the whole surface between C and E.  It appears to me that the area between A, B and C is recessed, making A and B appear to be raised.  I will use my surface plate and height gauge to confirm or refute this later today.  Using my micrometer, I have already confirmed the area between C and E is the same thickness, 0.353", at least within +-0.001".  I will have to rest the jig on parallels as there is a raised "Tormek" logo on the back of my jig.

To be continued...

Rick

You know what grinding marks look like...  Those are end mill cutter marks.  That is how I would have machined your jig, if I were the one you brought it to. 

Rick

Your measurement of the SVM-140 offset of 1.5mm is equally appreciated.

"Trust, but verify"

Rick

Tormek Knife Jig SVM-45 has 1.25mm spacing from the centreline of the handle to the bottom of the knife

Cross posting some discoveries I made today about the offset from centerline of my SVM-45 and 140

https://forum.tormek.com/index.php?topic=3445.msg21498#msg21498

Rick

You might look at wootz's "Knife Jig Solution"... see if there's a tip in there that will correct the asymmetry.  (I think this is what Rick is referring to).

"Your miles may vary"

Very interesting and informative thread.  Anyone interested in keeping the bevel width on each side of the blade as uniform as possible should study it (not just read it).  Interestingly, at least to me, I noted that Wootz refers to the offset from centerline as being 1.25mm.  Being curious, I disassembled my SVM-45 and started making measurements.  I tried several ways of making the measurements, mostly indirect.  But, finally, I realized I could make just three very direct measurements, using a very accurate and precise micrometer to come up with the numbers to compute the offset.  I worked in inch measurements and converted to mm. 

Measurement 1: Thickness of the Flat.

The fixed jaw on my SVM-45 is very flat and uniform near the transition from the shaft to the flat, offering two opportunities for good measurements.  I measured the thickness of the flat, from the back to the face (towards centerline).  0.352" (first photo).

Measurement 2: Thickness from the back Flat to the Top of the Shaft.
0.629". (second photo).

Third Measurement: Diameter of the Shaft.
0.471".  Important dimension is the radius, not the diameter, so  0.471 / 2 = 0.2355" (third photo)

Calculation:
Distance from the top of the shaft to the front face of the flat.
0.629 - 0.352 = 0.277"

Offset from centerline:  Difference between distance from the top of the shaft to the flat and the radius of the shaft:

0.277" - 0.2355 = 0.0415"  This converts to 1.054mm.  This is the offset from centerline, as measured on my very recently purchased SVM-45. It occurs to me that 1) these are castings (albeit precision ) and they vary, 2)  production process, including patterns change, so through time, you cannot rely on one person's measurement of one jig.

The take-away for me is that, anyone who is going to take things to this level of detail/precision should probably measure their own jigs, so as to determine for themselves, exactly what the offset from centerline they are dealing with.  It is very easy to do if you have a caliper or micrometer, and I would guess that anyone attempting to achieve the symmetry discussed would have these tools. 

It goes for different jigs as well.  I measured my SVM-140 and found the offset to be 1.5mm. 

Rick

CB and Rich,

Thanks Guys.  I am aware of that process, just haven't been using it.  Didn't know it skirts around the size limit, but it makes sense as the image is probably being viewed off the remote website.

Rick

Well, one thing for sure. You do not need help on how to post pictures! Great shots. There are many on this site that have a problem with that.

Actually, he may need some help.  Or maybe I do.  I don't know how he got those pictures to upload, given there is a size limit of 256kb (or so).  The first photo posted, when saved to my computer is 492kb and 1600x1200 pixels.  Given those numbers, the photo is so huge, we only see half or less of it.  Below is the same photo that I saved by download and resized to 640x480 and is 105kb.  It shows the whole machines, not just the left side and honing wheel. 

This is not a criticism, just an observation and comment.  I, for one, would like to know how to post an image so that it shows full size rather than a thumbnail that must be clicked on to view effectively. 

Rick

You might look at wootz's "Knife Jig Solution"... see if there's a tip in there that will correct the asymmetry.  (I think this is what Rick is referring to).

Asymmetry is what I was talking about and if I'd seen Wootz's post, I wouldn't have bothered, just referred to it.  I haven't read the post yet (entertaining granddaughter this AM), but I will with great interest.  Using a set of feeler guages is brilliant; very cheap and readily available.  My point, in part at least for the blade under discussion, was that the blade offset was slight enough as to not be the source of the asymmetry in the bevel width difference.  Perhaps after reading the post, I'll think differently.

Rick

Actually, my multi-tool is TTi. It is almost the same product as Wave. But if you look closely, the grinding is a bit different. The flat side is a little narrower. So it isn't fixed properly on the jig.

I have two SVM-45, but all have the same problem. I think the thumb hole is the cause.

Sharpco,

"the flat side" of what?  The jig or your knife blade?  If referring to the jig, I would call the flat side the "fixed" jaw and the side with the thumb screw the "movable" jaw.  The movable jaw is recessed about 0.5mm deep to about 15mm in from the leading edge.  At first glance, give that the unsharpened spine on my knife blade is about 2.4mm thick, I thought that would cause and offset of about 0.7mm from the actual centerlined of the jig and I thought that might lead to a slight difference in the width of the two beveled sides. 

But, if you look closely at the parting line (of the mold) along the SVM-45 shaft, you can see there it shifts a bit from the centerline of the shaft to the flat blade of the fixed jaw.  That shift results in an offset of the flat part of the fixed jaw of about 1mm.  For a blade like mine, that offset puts the centerline of my blade about 0.3mm off from the centerline of the jig (shaft).  I'm sure this is something that was carefully engineered by Tormek to try to accommodate the wide range of knife thicknesses the jig will see. If that is enough to cause the widths of the grind on each side to be substantially different, I'd have to have some with a lot more experience than me show how much difference it makes.

Maybe Jan, with his trig. and geometry could demonstrate it graphically. 

If I misinterpreted what you mean by the flat side, I've just gone on a interesting (at least to me) goose chase.  If you mean your blade has a flat side, without thinking about it much, I would expect difference in the grind width. 

Rick

Dunno.  Maybe it was due to not knowing any better, but I sharpened my two Leatherman Waves using the SVM-45.  These were some of the first knives I sharpened and I'd probably to a better job now.  I messed the tip up on one and the bevel width is wider towards the tip.  Given the reading I've done since, I'm sure that was due to poor technique. 

I'm not sure if it is a ricasso, but the blade has a narrow unbeveled section (~4.5mm wide x ~52mm long and 2.5mm thick) along the back edge of the blade. 

As I have mentioned in a couple of my posts, part of my motivation for getting a Tormek was realizing that the guy that I had taken my Wave to for sharpening several times was doing it on a Tormek using some sort of jig.

Rick