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the learning curve.

Started by Mal55, October 09, 2013, 06:29:51 AM

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Herman Trivilino

#30
Quote from: courierdog on May 03, 2014, 03:07:10 AM
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.

This is why I recommend something thicker, and the curved bevel will make it more rigid than a straight bevel.

QuoteYou finally decided to drill and tap the HK-50, have you had any second thoughts??

The tapping was done on the holes I drilled in the base of the scissors jig.  I have thought about a different design that would not require holes to be drilled in the scissors jig base.  If you look at its cross section, it has a bevel.  I believe a wedge could be made on the HK-50 that would accept the scissors jig base, and the wedge shape would hold it tight.  Perhaps a set screw could be devised that would prevent it from slipping.



This way the jig would be ready to use once built, and you wouldn't have to get nervous about drilling holes in your nice scissors jig.  Moreover, it could be assembled with no tools required.
Origin: Big Bang

courierdog

Herman, I understand the thickness issue when using a platform which has less rigidity than Steel.
Do you think I need to us a thicker base material even with the material being Stainless Steel?
I have no objections to drilling the SVX-150 Scissor Jig base or the SVD-110 Tool Rest.
It is only the drilling and fixing of the HK-50 by position, as it gives no further option.
While it is true the widest blade I currently have is a Chinese Chopper, if the Screws in the HK-50 are inset bevels an even wider blade?? can be accommodated.

Retired Engineer

Herman Trivilino

#32
Quote from: courierdog on May 03, 2014, 03:50:39 PM
Herman, I understand the thickness issue when using a platform which has less rigidity than Steel.
Do you think I need to us a thicker base material even with the material being Stainless Steel?

Probably not.  I never tried that material, but I had trouble with 1/8 inch thick aluminum.  It just wasn't rigid enough.  Originally I used a 1/8 inch thick piece of steel and it worked fine.  It was originally the blade on my neighbor's edger.  She had worn the cutting edge to a nub.

QuoteWhile it is true the widest blade I currently have is a Chinese Chopper, if the Screws in the HK-50 are inset bevels an even wider blade?? can be accommodated.

Yes.  Countersink the holes and use flat head screws so nothing stands proud of the top surface of the HK-50.  This is needed for cleavers, but also for some knives with curved blades or tips.
Origin: Big Bang

courierdog

Herman, The Stainless Steel stock I have is very substantial.
I will attempt to grind it down a little more before I drill the holes as the amount of work involved in girding is far more than drilling holes, which that in mind Drilling and Tapping will be last.
For some strange reason, I have noticed the SG-250 grinds faster on the Stainless Steel than the SB-250 which i find odd as I would have assumed it should have cut faster.
I considering, once the final amount has been ground away on my version of your HK-50, to polish it using the SJ-250 which should allow the water to shed faster than the rough surface.
Retired Engineer

Herman Trivilino

Quote from: courierdog on May 04, 2014, 12:25:04 AM
For some strange reason, I have noticed the SG-250 grinds faster on the Stainless Steel than the SB-250 which i find odd as I would have assumed it should have cut faster.

See what happens, just as an experiment, when you grind on a similarly-shaped piece of tool steel.

I'm thinking, as Jeff pointed out earlier in this thread, that you are not properly grading the grindstones with the stone grader.
Origin: Big Bang

courierdog

The one thing I did forget to mention about my Setup for grinding the profile on the HK-50 Knife Rest.
I use the Tormek SE-76 Square Edge Jig. Then using the WM-200 AngleMaster I set the angle to 10 degrees, Please NOTE, this must be rechecked after any significant amount of material is ground away from the HK-50 Knife Rest, and the angle must be restored by sliding the material forward in the Tormek SE-76 Square Edge Jig.  In this way I ensure the profile, (a) the correct profile angle and (b) is square to the Wheel throughout the process.
Taking care and moving slowly toward the goal will yield a uniform profile and make possible a near perfect work platform upon which to lay the blade during the future sharpening process.
Another though on preventing any abrasion to the knives to be sharpened is to consider the working surface of the Knife rest.
a) a thin layers of a plastic material, note regardless of how thin it is a thickness which will raise the knife blade above the rest and thus force the blade to hang in mid air.
b) Polish the work surface as you would a blade and always ensure both the blade and the rest are always coated in water, minimizing any friction between the blade and the rest, it also ensures a minimal amount of grit from the sharpening process is retain on the surface of the blade rest and the blade being sharpened.
When one studies the Japanese master sharpeners they dip the entire blade in water between sessions to remove any excess grit material from the blade and they also was down the stone and the associated surfaces.
A finely polished blade needs to be handled and sharpened with respect.
Retired Engineer

Stickan

#36
Hi all,
I have followed this discussion and first thought I should not take part of it but since knives are my favourite tool to sharpen, I want to share some info.

We can agree that we all want that perfect edge line from the heel to the tip of the knife. And that´s a bit tricky.
I guess mostly of you will find that the tip has a wider edge line than rest of the knife?
The knife jig´s design and function is very good but it will not work on every knife with the same adjustment or movement pattern. And we have to remember how many different types of knifes there is!

For chef´s knife it is very good to lift the handle upwards when you come to the tip instead of following the curve and drag the handle to you.
For hunting knives with a thicker blade , then you can follow the curve on the blade, but use a marker on both side´s an adjust the jig to find the right angle.
Knifes with small blades, use the SVM-00, with the same movement as for the chef´s knife.

Jeff Farris made a video about sharpening knifes and about 5 minutes in it, you can see that he lift the tip instead of following the curve.

http://www.youtube.com/watch?v=fYURcwkKGPs

Japanese knifes are really hot right now and there are a lot of discussion how to sharpen those the best way.
There are 3 things to think of, and that is witch material the blade has, use the right angle and a good wetstone.

I have a 90X magnifier available that I use sometimes to see how the edge looks like before and after sharpening, new or used knifes but also to see the difference between the stones. (SG-250, SB-250 and SJ-250) It has been helpful but it´s a bit over what you need to do.

All I need is a paper, or use my nail to see if the edge is gripping or simply test if it cuts away my arm hear. If it does, it´s sharp! And it always does.

And if you want to try on a tomato?
http://www.youtube.com/watch?v=igQ2VIcgOgE 

There is much more to write about knifes but it would take me to long but ask a question and I will do my best to answer it.
Knife sharpening is fun but you´ll need time to learn all the differences on the blades to get it right!






courierdog

Stickan, I would be very interested in learning a good deal more about sharpening knives. Knives are much more, IMO, an art form than just an acquired skill. Meaning, there is more than mechanical correctness, as each knife steel is different as is its intended use and is shaped for that use, but there is also the degree of how an individual uses that particular knife. As our hands are not created equal so we each adapt our skill or lack there of to facilitate each cutting stroke to achieve a a desired result.
The Tomato video is a starting point where I want to go with some of my knives, Usuba, Santoku, but not with the Syefu, Gyuto. At best the Tomato slicing is an acquired skill set as well as the knife sharpening, several tricks rolled together.
You are correct currently my knife tips have a wider edge bevel than I would like to see.
I fell and injured my left hand in Nov of 2013 and have sustained a carpel tunnel injury. Md says an operation my acupuncturist who is a Chinese medical doctor says I should be able to avoid the invasive operation.
This injury is affecting the way I use my hands to sharpen my knives.
Retired Engineer

Herman Trivilino

Quote from: courierdog on May 05, 2014, 04:01:10 PM
You are correct currently my knife tips have a wider edge bevel than I would like to see.

Move the jig (SVM-45) closer to the tip of the knife.
Origin: Big Bang

courierdog

Herman, I did try moving the SVM closer to the tip. I am finding using the HK-50 is closer to sharpening with a flat stone which my hands are more able to control the blade passing over the stone.
Retired Engineer

Herman Trivilino

Plus, you avoid that whole issue of a wider bevel near the tip.

By the way, I adjust the bevel angle with the HK-50 resting on the grindstone.  Then I tighten the set screw so it can't rotate about the universal support.  Then I rotate the micro-adjuster to lift it off the grindstone, and then finally I tighten the two set screws that lock the universal support in place.

Origin: Big Bang

Ken S

I believe the Tormek philosophy is complete control and repeatability for general through the use of various jigs.  Using flat stones and Herman's jig seems more oriented to achieving the same precise results with more manual skill. The two seem complementary.  I think a well prepared sharpener should be fluent with both.

Ken

courierdog

Quote from: Herman Trivilino on May 06, 2014, 03:41:50 AM
Plus, you avoid that whole issue of a wider bevel near the tip.

By the way, I adjust the bevel angle with the HK-50 resting on the grindstone.  Then I tighten the set screw so it can't rotate about the universal support.  Then I rotate the micro-adjuster to lift it off the grindstone, and then finally I tighten the two set screws that lock the universal support in place.
Herman, thanks I must have missed that, if you had stated that in past threads.
Makes more sense.
I am in the process of re-grinding the HK-50 (StainlessSteel) platform. I am attempting to more closely match the HK-50 profile to that of the grinding wheel and more polished as well. Very time consuming, for sure. I am hoping my end results justify the added effort. LOL
Retired Engineer

courierdog

Quote from: Ken S on May 06, 2014, 07:43:49 PM
I believe the Tormek philosophy is complete control and repeatability for general through the use of various jigs.  Using flat stones and Herman's jig seems more oriented to achieving the same precise results with more manual skill. The two seem complementary.  I think a well prepared sharpener should be fluent with both.
Ken
Ken, I do not find the Tormek knife jigs work for the way my hand to eye coordination works. Herman's HK-50 style is giving me more consistent results. As you have also noted I am grinding further on my version to allow less blade overhang to achieve the desired edge bevel. Not an easy task.
Retired Engineer

Ken S

Retired engineer,

I don't doubt what you say.  I worked as a telephone man in the old Bell System.  We all received the same standardized training.  At one point, some distant manager tried to make the supplies on all the trucks stored in identical places.  That brilliant idea was short lived.  Even though we were supposedly trained alike, we thought differently. Even with something mundane like the sequence of the color packs, the man who left me his truck thought near to far, and I thought left to right.

In addition to thinking differently, we come to the forum with different levels of hand and eye coordination and different levels of experience.  In my case, I am more comfortable doing final honing with water or oil stones.  That is not because they work better; I have just worked more with them.  For the same reason I owned the knife jigs for several years before I actually tried them.  I am still not totally fluent with the knife jig. I have only sharpened my own knives, and attribute my lack of confidence to lack of experience.  More time at the wheel may help.

Whenever something does not work well for me, I tend to consider the possibility of operator error.  YOu have established a very high bar with your experience with flat stones.  I hope you find a technique which satisfies that standard with the Tormek.  It may be with Herman's jig rather than the customary jigs.  Either way is fine.  I hope you will continue posting.  I have always felt the Tormek is an excellent machine with room to grow. let's keep growing.

Ken