How do you do you S grinds?

[MattM82]

Hi all,

I’ve started a blade with an S grind and just wondering how others go about it. In doing some research I see a lot of grinds where the top of the hollow stops in line with the bottom of the ricasso, and others that are higher.

What’s your preference and why?

I’m doing a 210mm long, 53mm high blade, 4.3mm thick spine at the heel and used a 14” wheel to do the hollow.

I flat ground the blade to a 2mm thick edge, heat treated the blade, I then ground in the hollows, flat ground it a little more and started some test cuts.

Next I’m going to convex the flat below the hollow in to a zero edge.

Still a lot of clean up and refining of grinds to go but so far so good.

I have a 72” water-cooled radius platen I can also use but it’s a pretty subtle hollow. I’m thinking of getting a 36” radius platen to try as well.

Keen to hear others makers methods.

Cheers

Matt

 

[RDalman]

I begin with making a distally straight sharp edge, then I thin it until about silly. Then I grind the rest of the blade, refine as I go, until it will cut the way I want to. The grinds will look ok if all comes together. I do not care where any hollows are positioned much, they're a result of everything else, when blade is finished out. If I can approach decent consistency of ease in cutting balanced with food release, then I'm happy.

 

[MattM82]

I begin with making a distally straight sharp edge, then I thin it until about silly. Then I grind the rest of the blade, refine as I go, until it will cut the way I want to. The grinds will look ok if all comes together. I do not care where any hollows are positioned much, they're a result of everything else, when blade is finished out. If I can approach decent consistency of ease in cutting balanced with food release, then I'm happy.

Thank you for your response. Definitely a little different to the way I went about it but the refinement process sounds the same.figure I’m close the the right track so I’ll continue in and see how it performs.
Thanks for your time.
Matt

 

[Kippington]

I'm with Robin - The cutting part of the knife takes priority and comes first. Move on onto the hollows after the blade can cut well.

Actually, my first attempt looked really similar to yours, the grind anyway. It's difficult to know how thin the hollows are getting if you have distal taper along the blade, and mine snapped in half when I tried to straighten it (grinding a hollow can warp some steels). The choil was also really uncomfortable.
I don't do the process anything like this anymore.

 

[MattM82]

I'm with Robin - The cutting part of the knife takes priority and comes first. Move on onto the hollows after the blade can cut well.

Actually, my first attempt looked really similar to yours, the grind anyway. It's difficult to know how thin the hollows are getting if you have distal taper along the blade, and mine snapped in half when I tried to straighten it (grinding a hollow can warp some steels). The choil was also really uncomfortable.
I don't do the process anything like this anymore.

Appreciate the response, thank you. Definitely some good pointers to keep in mind. Thanks