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View Full Version : New Geometries Offered - Convex and Asymmetric Convex



Marko Tsourkan
05-09-2014, 03:43 PM
Just to give you guys some heads up.

I am going to start offering these as my ready-made knives, and do S grind only as custom orders. Unfortunately, S grind takes me 50-60% more time to grind and hand-finish a blade and it is hard for me to stay competitive.

There will be 2-3 variants, ranging from thin, medium, heavy (heavy duty prep knife, similar to Kato) convex. Asymmetric convex will be offered with wa handle only.

These will be good all around knives, with excellent HT (sharpness, sharpen-ability, edge retention and edge stability). I am going to offer these in 52100, A2, and AEB-L. Target hardness 62-63RC. These knives will be offered with leather and wooden sayas. Blades will be hand finished.

Thanks,

Marko

jgraeff
05-09-2014, 03:58 PM
Sounds great Marko!

I'd like to see a comparison between your grinds and performance.

Matus
05-09-2014, 04:48 PM
Marko - what should one expect concerning food release when comparing the S grind to convex one?

Marko Tsourkan
05-09-2014, 06:28 PM
The release on my convex blades will be comparable to other US makers who grind their blade to true convex (spine to edge vs convexed edge).

Heavy convex will have the best release out of the three as also will asymmetric convex, due to the smallest contact area on the sides. Thin and medium will glide through food with less effort.

S grind has better food release on most things in my opinion, but is also the hardest to produce.

jgraeff
05-09-2014, 08:46 PM
Marko,

I have been looking for s grind and can't find anything online just curious can you explain it?

Marko Tsourkan
05-09-2014, 11:11 PM
I think we can credit Devin for the coining the term S-grind (among other things) as the grind resembles the letter S. It's a combination of a convex and a concave grind.

The aim of this geometry to reduce a food contact surface to facilitate better food release and to reduce friction, as well as to lighten a blade. Shigefusa and Takeda are the only other two makers (known to me) that use this type of grind. In non-knives cutting things, I have seen this grind on axes and straight razors.

To my best knowledge, the S-grind blade can't be finished on a machine well, so there is quite a bit of elbow grease (hand sanding) to blend these two geometries into one, adding to a production time.

When I started making knives, I was grinding them in medium convex geometry. Over time I switched to S-grind as it was my personal preference and I thought it was a better grind for pro chefs who use up a knife faster than home users and would would find it easier to thin and maintain down the road.

Most knives by US makers are either convex ground, or flat ground with convex above the edge.

Marko

Steel in Texas
05-10-2014, 02:33 AM
Ready made knives... did I hear there might be a Marko knife available for sale... perhaps a wa handled asymmetric convex grind gyuto in AEB-L... :begging::begging::begging:

jgraeff
05-10-2014, 09:16 AM
I think we can credit Devin for the coining the term S-grind (among other things) as the grind resembles the letter S. It's a combination of a convex and a concave grind.

The aim of this geometry to reduce a food contact surface to facilitate better food release and to reduce friction, as well as to lighten a blade. Shigefusa and Takeda are the only other two makers (known to me) that use this type of grind. In non-knives cutting things, I have seen this grind on axes and straight razors.

To my best knowledge, the S-grind blade can't be finished on a machine well, so there is quite a bit of elbow grease (hand sanding) to blend these two geometries into one, adding to a production time.

When I started making knives, I was grinding them in medium convex geometry. Over time I switched to S-grind as it was my personal preference and I thought it was a better grind for pro chefs who use up a knife faster than home users and would would find it easier to thin and maintain down the road.

Most knives by US makers are either convex ground, or flat ground with convex above the edge.

Marko

Awesome thanks Marko!

Marko Tsourkan
05-10-2014, 11:39 AM
The idea is to keep getting some knives out, while my custom order list is closed for some time. I need to be able to generate some additional resources more efficiently, as my overhead cost keeps getting higher and that puts quite a bit of pressure on me.

I will do convex and asymmetric convex, and possibly some S grind as ready-made, but latter will have to be priced higher. Realistically, it will be about one blade a week.

AEB-L in the thickness I like to work in is on the way.

icanhaschzbrgr
05-10-2014, 05:00 PM
Cool.
Are those ready-made knives are going to be sold as lottery? As you may have noticed already, your knives are really hot here and usually sold in minutes in BST. So one knife in a week probably wouldn't change the situation…

Marko Tsourkan
05-22-2014, 12:20 PM
Just to give you some heads up on asymmetric convex. There will be two variations of this geometry offered, a workhorse and a laser. First one is a great knife for prep work, when moving through volume of produce is the goal. It will come in AEB-L, 52100 and A2

thinner version will be more of a detail knife, lighter and more nimble.

Marko Tsourkan
05-27-2014, 08:32 PM
Making some good progress on grinding knives in asymmetric convex geometry. Just a little more testing and feedback and this might join the S grind as my favorite geometries.

M

cruelraoul
05-27-2014, 11:02 PM
Can't wait to see them!

Marko Tsourkan
05-28-2014, 12:28 PM
I will do a video between performance comparison between these geometries in the next couple of weeks.

cruelraoul
05-28-2014, 01:30 PM
A video would be neat-o. Based on your targets and initial build observations, do you have any idea on what the general production volume of the new grinds might be over time? This would help us know the chance of general availability.

Marko Tsourkan
05-29-2014, 02:14 PM
I should probably include a convex blade in the video as well.

Come to think that I should to call the S and Asymmetric grinds - composite geometries (comprised of two geometries), and convex - single geometry, to differentiate the three.

Marko Tsourkan
06-03-2014, 03:11 PM
250mm Asymmetric Workhorse in A2, Western handle, approx. weight 275g. 63.5RC.


https://www.youtube.com/watch?v=xSprfvog2tk&feature=youtu.be

Marko Tsourkan
06-03-2014, 03:36 PM
250mm Asymmetric Workhorse in A2, Western handle, approx. weight 275g. 63.5RC.


https://www.youtube.com/watch?v=qEIFd5nbaKU&feature=youtu.be

Anton
06-03-2014, 03:43 PM
nice cutting board .... :D

Marko Tsourkan
06-03-2014, 03:48 PM
250mm Asymmetric Workhorse in A2, Western handle, approx. weight 275g. 63.5RC.


https://www.youtube.com/watch?v=zSJhLYcmymI&feature=youtu.be

WildBoar
06-03-2014, 03:49 PM
Good stuff, Marko. For a hefty knife that seems to conquer wedging. Congratulations!

Marko Tsourkan
06-03-2014, 03:54 PM
Thank you, I have been working on this geometry on and off for almost a year.

So folks, there you have it. Excuse my poor form, I always seem to manage to cut myself before demonstration (middle finger on my left hand) and can't put much pressure on that finger.

I will do a series of similar videos for S grind and convex in a couple of days.

PS: I purposefully scraped food of the board in the third video. I know you guys wouldn't approve. LOL

Anton
06-03-2014, 04:01 PM
Very good stuff Marko. thanks for the videos

jgraeff
06-03-2014, 05:27 PM
Cool looking forward to seeing the others

Marko Tsourkan
06-03-2014, 11:07 PM
Cool looking forward to seeing the others

Will do videos of S grind tomorrow.

rami_m
06-03-2014, 11:23 PM
Will do videos of S grind tomorrow.

I hope you will use a certain knife, that would be so cool. :D

Marko Tsourkan
06-04-2014, 01:11 PM
250mm gyuto in 52100, S-grind, Western handle, approx. weight 245g.


https://www.youtube.com/watch?v=X7IS9aiiCdw&feature=youtu.be

Marko Tsourkan
06-04-2014, 01:18 PM
250mm gyuto in 52100, S-grind, Western handle (shown without), approx. weight 245g.


https://www.youtube.com/watch?v=4xbFVEgu-Ls&feature=youtu.be

ramenlegend
06-04-2014, 01:24 PM
knives look great, where do I send my money? :D

Marko Tsourkan
06-04-2014, 01:31 PM
250mm gyuto in 52100, S-grind, Western handle (shown without), approx. weight 245g.


https://www.youtube.com/watch?v=2BpYPutkogU&feature=youtu.be

jgraeff
06-04-2014, 01:35 PM
S grind seems to have less sticking. How does horizontal cutting compare? Both seem to cut well but is there a difference in feel?

Marko Tsourkan
06-04-2014, 01:37 PM
So, folks there you have it - the S-grind videos. Once again, these were to demonstrate the ability of the geometry rather than my cutting form (poor by all means, in part because of an injured finger).

This blade is just a little bit lighter than an asymmetric convex blade in the same length, but still has the proper rigidity on the spine (no flex). The sharpness on this blade is far from it's potential - I just put a quick edge for the videos. The knife is obviously a work in progress, ground and roughly finished, so the Western handle and the final polish is still ahead.

Thanks for watching,

Marko

Marko Tsourkan
06-04-2014, 01:38 PM
S grind seems to have less sticking. How does horizontal cutting compare? Both seem to cut well but is there a difference in feel?

S grind will perform better in horizontal cuts, but not by much, as the tip area of asymmetric blade is at its thinnest.

I think there is probably no geometry that would offer no sticking on shallow stuff, but overall, the food separation on S grind and asymmetric convex is comparable on the few things that I cut.

WildBoar
06-04-2014, 01:52 PM
Very nice, Marko. The s-grind really seems to do a nice job. You have a real future as a premier knife maker. BTW, which grind wedged less in your finger? :D

Marko Tsourkan
06-04-2014, 02:01 PM
Believe it or not, I got cut by Son's knife made by Roy Rogers while I was polishing it. It had a plain convex geometry, but still cut badly nevertheless, probably in part because Tihn thinned it and sharpened. :D

jgraeff
06-04-2014, 03:10 PM
Very nice, Marko. The s-grind really seems to do a nice job. You have a real future as a premier knife maker. BTW, which grind wedged less in your finger? :D

Marko is a premier maker IMO. I have used plenty of Devin Thomas, carter, shigefusa, and Kramer and there is a reason I own a Marko aside from price. Now don't get me wrong if love to have a knife from any if these makers but I feel Marko is just as good currently and can only get better from here.

I feel Marko offers more of a value than the others with exceptional performance. Mine is 2 years old In a pro kitchen and still my favorite and most used knife. Can't wait to get another one down the line.

But I would like to know as well about the wedging In the finger haha

Marko Tsourkan
06-05-2014, 03:30 PM
There will be a thinner version of asymmetric convex, and the knives will be offered as lasers. For now this version will only be available in AEB-L and in 225mm length for gyuto and 275mm for suji. At some point later I will include longer length gyutos.

S grind will be standard grind - no lasers, though I do grind my blades to very thin above the edge, so with a good food separation, it might feel like one.

The finger cut is right on the tip of my finger, so it's hard for me to apply pressure - something I do a lot while grinding and polishing, so I took it easy these past couple of days, but am back at full speed at work today.

rami_m
06-05-2014, 05:10 PM
Good to hear.

Marko Tsourkan
06-09-2014, 06:44 PM
I will do some quick videos on how these grinds work on sujies. At this time, S grind and Asymmetric are ones I offer.

250mm suji, Asymmetric grind, Western handle (shown without a handle).


https://www.youtube.com/watch?v=zVEF-cVFmPQ


https://www.youtube.com/watch?v=u0THvsJmWGw

Marko Tsourkan
06-09-2014, 10:16 PM
I think for cutting proteins (with a suji), asymmetric grind might be a better fit. In terms of thickness above the edge, both asymmetric and S grind are about the same.

I am offering these grinds as I think they are probably some of the most performing geometries out there.

M