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And they are doing a live session (drill sharpening) today at 15:30. Sorry for the late notification.

https://www.youtube.com/watch?v=AIYfsqFfx-c

BR
Torben

Hi Jan,

Some time ago I made my own excel sheet to calculate these things. My calculations are not based on trigonometry but on vectors. I believe that my method does not introduce any errors.

You mention a new formula that you believe is correct Jan. I would very much like to compare my numbers with that. I have been searching this forum for 'ton', 'booklet' and more but nothing has showed up. Is this formula available for me? If so, can you help me find it?

BR
Torben

Thank you all for your response. I am relieved that you didn't write that I should buy a new wheel .

To make chromium oxide creamy, you can dilute it with liquid vaseline.

I think that the Tormek oil does not dilute the chromium oxide very well. If liquid vaseline does it better I would prefer to use that. Would that be okay?

After that, as you start doing your knives, you will see that the edge on the first couple of knives may not come out as sharp as it will on the following knives - the thinner the chromium oxide, the better the result. So do not reapply it too often, only once in 4-6 months.

Ahaaa... So the problem is that I have applied too much. I read that the amount of paste I bought should last a life time so I wondered why I had already used half of it . That also explains why I have not gotten the results that I hoped for. I will scrape off the excess paste and then see if the results get better after I have honed some more knives.

Strictly out of curiosity, what are the advantages of using chromium oxide instead of PA-70?

Ken I plan to use my chromium oxide wheel after using the PA-70 leather wheel or the SJ wheel.

Torben

Hi sharpeners  ,

I have run into some problems, so I hope you can help me. 

I bought a new leather wheel with the purpose of dedicating it to chromium oxide. I then ordered some chromium oxide paste, which I can no longer find online, but it is shown in the 1st attached picture.

When I received and opened the can of paste it was to my surprise very hard. Not like paste at all but more like a block of honing compound. See 2nd attached picture.

As I had no way of getting it out of the can, I applied a little of the oil that came with the leather wheel and with the help of a toothbrush I was able to dissolve (dilute?) some of the 'paste' and apply it to the wheel.

I have done this several times prior to using the wheel and now I am unsure if it was the right thing to do. The wheel now looks like this (3rd attached picture) and if you look closely you can see that the 'paste' sort of rolls off. During use it can get a lot worse than shown on the picture and even though I regularly stop and wipe it away, I believe it is not supposed to be like this.

So... What am I doing wrong? and what must I do now to get a well working chromium oxide wheel and how should I do it in the future?

Thanks in advance 
Torben 

I drafted this out in my CAD program.

The distance from the bottom rear of the fixed jaw to the close side of the raised logo is 39.63mm (1.560") (I did this in inches and rounded the mm's so there may be some slight discrepancies in the mm numbers).  The distance from the bottom rear to the front of the jaws is 84.84mm (3.340"). 

I drew a parallel line at length 39.63mm and then another offset 0.18mm (0.007") which is the height of the raised logo.  I then drew a line from the bottom rear point to the raised logo height point.  And THEN projected that angled line to 84.84mm to represent the front jaw height.  The offset of that front jaw point from the parallel line was 0.38mm, which if rounded yields 0.4mm. 

0.4mm is exactly the number you got with your measurements. 

I see your point about the TORMEK logo on the back side of the jig Rick and the fact that you are able to derive the same 0.4 mm difference as I measure, verifies that the difference is caused by the raised logo.

I was aware of the logo when I did the measurements. However as you have now derived that the raised logo lifts the end of the jig where the knife rests by 0.4 mm, I would also expect the other end of the jig (the shaft) to drop. I measured the distance from the ground surface to the top of the shaft - in each end of the shaft (see attached picture), and found the distance the same in both ends. So I concluded that the shaft was in parallel with the ground plane and hereby the centerline of the jig too. This I still don't understand.

After reading your post I have remeasured the shaft and also measured on the jig when I push the raised logo just outside the surface that the jig rests on, with the purpose of cancelling the effect of the logo. I have measured many times but I must unfortunetaly conclude that I am not able to achieve consistens accurate results. I do not posses the proper measuring equipment and maybe also the skills to do this. So I have to stop here. It bothers me to leave this without fully understanding, but without being able to make accurate measurements I will not get any further.   

Thank you for your effort and response cbwx34 and Rick.

Torben

Torben, from your reply I see you understand that really in depth! 

And then clearly not . cbwx34 has been so nice to inform me that I got it backwards. So to save some honour I hereby state that I have not got it backwards, I just wrote the opposite of what I mean  . What I meant was...

I put a 2 mm thick blade in the SVM-45 jig. The angle master tells me that bottom side of the blade (in touch with the bottom part of the jig) is sharpened at a higher angle than the top side. This leads me to conclude that the blade center line is above the jig center line and hence the knife is too thick for the jig.

Hope I got it right this time.

Jan just like you, my (little) experience with this machine also tells me that I will not be able to see these small difference with a naked eye. But I find it quite funny analysing and maybe optimizing these small things. It makes me feel I'm in control of the sharpening process. I hope it is ok to enter nerd mode once in a while. I can see I am not the only one doing it in here

Torben

cbwx34 and Rick thank you for your messages and effort to investigate my observation. I will post a reply here soon...

Jan thank you for your input. I have seen your post before about this. I respect your way as I have also realized that this is more complex than I first thought it would be . But... 1.25 mm seems like a lot to me. When I mount my 2 mm thick kitchen knife in the SVM-45 jig and I compare the angles on each side of the blade with the anglemaster, the anglemaster tells me that the side of the blade in contact with the bottom part of the jig is sharpened at a slightly smaller angle than the other side. This is, according to my understanding, caused by the center of the knife blade being above the centerline of the jig, meaning that the knife is too thick for this jig. Your estimation says that the jig should sharpen a 2.5 mm thick knife symetrically. I do not own a 2.5 mm thick knife but I expect the asymmetry would be significant. Does this work for you? And if yes, can our jigs vary that much? I saw a picture in here of a SVM-45 where the shaft was not straight at all.   

I am aware that the way I mount the knife and tighten the jig can also influence the angle but I pay attention to this and I do it as advised in this forum.   

Torben

Hi all,

This is my first post in this forum. I bought a T8 a few months ago and have so far only been reading in here, learning from all the experience gathered. I must admit my expectations have not been met with this machine. Being used to sharpen knifes with water stones I expected to sharpen knives fast and precise right away. That didn't happen . So far I am still learning but the results are getting better even though sharpening a knife still takes me forever.

The reason why I am replying to this inactive thread is that it is the newest I could find that deals with the asymmetry of the SVM-45. In this thread and another (https://forum.tormek.com/index.php?topic=3445.msg21408#msg21408) Lape and RickKrung measure the jig. You both measure the thickness of the flat to around 9 mm. This figure is then used to calculate the offset to the jig centerline and you both get around 1 mm and it is then concluded that a knife with a blade thickness of 2 mm will be symmetrical placed in the jig.

I have done the same measurements as you guys and I get the same numbers. However I believe that the measurement of the flat thickness (9 mm) is measured at the wrong place giving a wrong result. What I did was to place the SMV-45 bottom part on a flat surface. I measured the distance from the top of the shaft to the flat surface in each end and as it was the same, I concluded that the centerline of the jig was in parallel with the flat surface. Then I measured the distance from the flat surface to the top of the flat in the same place where you have measured it, and I also got 9 mm. However when measuring the distance from the flat surface to the top of the flat at the end of the jig where the knife is resting the distance was 9,4 mm. If you look at the plane where the knife is resting, in each side of the jig the surface is a little big higher (sorry for my bad vocabulary  ). This is also visible on the 3rd picture in RickKrung post in before mentioned thread.

A distance of 9.4 mm leads me to conclude that the offset to center line is only 0.6 mm and that my jig (I know there are several versions) is made for a blade thickness of 1.2mm. I have checked this with control measurements with the angle master and they verify this. If I mount a knife with a blade thickness of 2 mm in the jig, I get a smaller angle on the side of the knife that rests on the bottom part of the jig relative to the other side.

As many of my knifes are around 2mm thick, this leads me to conclude that I need to take some material off the SVM-45. This seems drastic as all of you (except Wootz) are talking about inserting spacers instead. So if any of you guys still have an interest in this, please comment. Am I overseeing something? I will postpone the modification for now .

Thank you all for sharing your knowledge in here guys. I have learned a lot from you and there is still a lot more to learn . 

PS Sorry for the orientation of the picture. I can't get it right.

Torben, Denmark