the learning curve.

[Jeff Farris]

While this observation is expected when using the SG-250...
Even with the SJ-250 I am getting the somewhat wavy patterns on the sharpened blade which is a factor of my lack of skill using the Tormek to sharpen blade steel..

If you're changing the profile of a knife with the SJ-250, you're a much more patient man than I am. It takes me forever to remove any measurable amount of steel with the SJ-250. How much time are you spending on the knife with the SJ-250 to create a wavy edge?

[grepper]

Just to be clear, by "wavy edge" do you mean:

If you hold the knife perpendicular on a flat surface as you would when you are cutting, that the cutting edge does not contact the flat surface over its entire length?

[courierdog]

I learned to sharpen knives using the flat Waterstones by watching https://www.youtube.com/watch?v=CO7KdLZY7fQ and lots and lots of patience practice.
Plus I also use an Edge Guide to maintain a constant edge angle http://www.paulsfinest.com/Edge-Pro-Guide-Clip.html
With the above process I am able to produce a very respectable edge.
I use the 400 grit to remove any chips or gouges
I use 1000 grit to sharpen
I use 5000 grit to polish the sharpened edge.
Now my challenge is to learn how to sharpen the same knives using the Tormek, which is a totally different process to that of Flat WetStones.

[courierdog]

Wavy Edge using the SJ-250
Any imperfection no matter how small create a difference in the mirror finish like a wave in the mirror finish, hence a wavy Edge.
Inconsistent Edge using the SG-250
Any imperfection while using the SG-250 creates a definite and distinct edge bevel change which can only be changeded by careful consistent drawing across the grindstone.

[courierdog]

Hmm, I have never been very good a long steady strokes.

My hat goes off to anyone who can do that.  I've never been able, which is what prompted me buy the Tormek to begin with.  That was followed with the development of the HK-50 because I couldn't even master freehand sharpening with the Tormek.

I have ground a Stainless Steel version of the HK-50 as I followed your many threads thinking this would enable me to emulate your experience. When it comes to the narrow angles used on the Japanese Knives (less than 15 degrees) I have found to date I am unable to replicate your experience. I will attempt to grind down the HH-50 to a finer edge to allow me to achieve more knife blade on the HK-50 and less in the air before coming in contact with the grind stone.
Like yourself I think this process should produce a more controllable edge.
Caution, To Date, I have not been able to achieve good, consistent, shallow angles as used on the Japanese Kitchen Knives.
ANY Suggestions would be appreciated in this regard.
As with any sharpening process a consistent contact between the work piece and the grind stone is essential to achieving repeatable results.

[courierdog]

Posting of pictures
I wish the Tormek community allowed the posting of pictures, it would make any explanation much easier. I do not find using Photobucket easy or as some have experienced safe.
So much of what were experience is visual in nature and thus pictures would enable a freer expression of our thoughts, while I may agree that my mind's eye can see many things I am unable to produce in real life regardless of the material, or subject I use, ha ha
The Wavy Edge is not easy, for me, to photograph, yet I can see is plain as day, even is less than ideal lighting.
I will admit the sharpening with the Tormek is progressing, but not always in a positive direction. The Knife Edges are beginning to approach that of my skills with the flat stones.I m not ready to trust my really expensive Japanese knives to the Tormek in my unskilled hands yet. A good deal more practice on the Tormek is required before that will happen. As I have found so far with the Tormek, once the secret of how to hold your tongue is learnt for a particular sharpening procedure then everything is golden. Kitchen Knife blade sharpening is not as easy as some would attempt to make you believe. It is very exacting and I believe few attain the perfection required for consistency. This is why we have so many Jigs invented for various tools which require precise sharpening. Kitchen Knives are not like any other blades.

[Herman Trivilino]

So a wavy edge refers to waves on the surface of the ground edge.  I doubt you're getting those with the SJ.  Is it possible they were already there and the SJ makes them more visible because it's polishing them?

[courierdog]

Herman, that is an interesting observation.
So are you suggesting I be much more careful using the SG-250 to correct the blade irregular bevel issues.
Perhaps you have a valid point, The Edge must be perfect with the SG-250 before proceeding to the SG-250. As I think on this I believe you are correct. The SJ-250 does polish very well however it can only polish the surface it has to work with.
Many thanks for this intuitive observation which had been hidden from my view due to my being overly focused on the surface instead of the underlying problem.

[Herman Trivilino]

Also keep in mind that in many cases kitchen knives perform better when the surface of the bevels are not smooth.  Many people like a "tooth" to help with, for example, slicing tomatoes.

My understanding of knife edges was really helped along by my observations at a magnification of 40X.  There you can see the "teeth" carved into the bevel's surface.  Is it really worth it to obsess over the waves, or multiple facets as I've heard others call them.  The first time you use the knife, and then take a steel to it, you can see that the edge takes a lot of abuse.  Good knives are designed to perform well under these circumstances.  We don't really refer to this as abuse.  It's just normal wear and tear on the knife edge.

The most important thing is to keep a steel handy, and never put them in the automatic dish washer.

[courierdog]

Herman, at one time I also believed the concept of "tooth" for slicing tomatoes, that is until I personally watched one of my knives sans teeth slice through a tomato repeatedly on edge without disturbing the slice above it.
I was able to keep the same knife with this kind of edge using the flat stone. Learning to do the same with the Tormek is my personal objective. The Japanese chefs I have spoken with do not use a steel they use a very fine grit waterstone 10000 or better. All sharpening is done with a 1000 grit stone, the 400 grit stone is only use to remove imperfections.
It took a lot of time to learn how to use the flat waterstones.
It is, for me, more difficult to learn how to do the same with the Tormek. I am confident once I learn, I will wonder what took so long. I have to go back and see if I can obtain a finer angle for my HK-50 to allow me to have better control of the sharpening process over the entire length of the knife blade, similar to the control I had while using the flat waterstones.
I do not find I have the same fine control with the SVM45 or the SVM140, at least not with my hands.

[Herman Trivilino]

The bevel on the end of the HK-50 should be curved to match the curvature of the grindstone.  That will allow you to make the end stronger and thinner.  You do not want the end of that bevel to meet the top surface of the platform, if you do it will form a sharp edge.  Instead you want a flat surface, but you want the thickness of that flat spot to be as small as possible without it becoming flexible.

The geometry I decided on was a minimum bevel of 10^o with a thickness of 1 mm.

The final version of my HK-50 is aluminum with an adhesive-backed felt on the top to prevent scratches on my knives.  I have rougher versions made of wood and plastic that I use for things like lawn mower blades.  I save the nice one for finer pocket knives and kitchen knives.

[courierdog]

Herman, minimum bevel of 10o with a thickness of 1 mm is exactly what I was attempting to achieve.
However, I seem to be observing more overhang of the blade than should be possible. with a 2 inch wide blade I have more than 1 inch overhang. this does not feel right, nor does it give the finger control of the blade I am looking for.
I must be doing something wrong in the setup.
My gut tells me I should be able to achieve a small overhang with the desired bevel angle for blade sharpening.
My experience with sharpening on flat stones, tells me I should be able to achieve a similar feel using the Tormek Round Wet Stone. The advantage of the end result is a very slight undercut giving a microscopic hollow grind to the finished, polished blade edge. This emulates the original intent of the Japanese creators of the blade. All be the differences that they use a 2-3 foot diameter stone as opposed to the 10 inch of the Tormek.
I feel if I can achieve the proper shape and angle of the HK-50 style blade rest I should be able to have a similar finger feel to that of the Japanese Water Stone. The Edge Pro, http://www.paulsfinest.com/Edge-Pro-Guide-Clip.html, I have used to achieve a consistent edge angle on the Flat Waterstone should be similar to using the HK-50 if shaped in an equivalent manner while providing better support of the blade during the sharpening process.

[courierdog]

Herman, I made at least two mistakes
1. I did not bring the HK-50 Platform close enough to the desired angle, I needed another mm off of the leading edge and I had to pay particular attention to the total relief of the underside to match tat of the grinding wheel.
2. was not securing the HK-50 close enough to the rotating stone. If it removes even a small amount it does not matter.
I now am able to be begin to approach the edge I was getting with the Japanese Flat waterstones.
This is a huge relief off of my mind.
Thank you for staying with me as I struggled through the process.
Once the proper set up (HK-50) is built/fabricated/ground the sharpening process is very similar to that of the flat waterstones except the stone rotates instead of moving the blade across the stone.
The difference is holding and moving the blade across the moving (rotating) wheel.
I now can concentrate on perfecting the process to achieve the RAZOR sharp edge these knives deserve.

[Herman Trivilino]

Look at this thread, especially Reply #7.

http://forum.tormek.com/index.php?topic=1592.msg6634#msg6634

[courierdog]

Herman, Exactly!!
Re: Homemade Knife Rest (HK-50)
« Reply #7 on: March 23, 2013, 05:52:03 am »
Quote
Here you can see that the bevel angle is about 10 degrees.  This is where I am attempting to build my version of the HK-50. You can also see how close a knife blade will be able to get to the grindstone. The 1/8 inch Stainless Steel version I am working on is slowly coming together. The thinner you get it the closer you can get to the grindstone. This is what I am attempting to achieve. However, make it too thin and it won't be rigid enough to stand up to the pressure applied by the operator when sharpening a knife. I am hoping that the 1/8 inch Stainless Steel will have sufficient strength and rigidity.
I am very thankful for your initial concept and write up of the HK-50 which got me to rethink my sharpening process as the SVM45 & SVM140 jigs are not providing me with the degree of control I desire while sharpening my high carbon steel knife.
blades.
As you persisted with the development of your design it really go me to thinking and as I read reply #28, 31 and went back to Ionut's Small Knife Jig Reply #1 where a spark of enlightenment came to me and I went and bought a piece of 1/8 inch by 2 inch by 12 inch Stainless Steel.
I am not at the point of drilling and tapping as I am concerned I may need a different platform angle.
You finally decided to drill and tap the HK-50, have you had any second thoughts??