Usuba Project

This is a blade I've been wanting to do for a while, and I got these heat treated blades back about a month ago or so.
There are other projects ahead of these, but I wanted to ask advice here before I start the work.
These are 4.65mm thick, with no current taper. 52100 at 63 hardness.
Before HT i ground just a slight urasuki, really just a slight groove, and put a short bevel on the edge side to help reduce belt wear on the real grind.

What I wanted to ask about specifically is whether and how much to taper from heal to tip.
Keep tip as is or more traditional round shape?

I am planning to use my 14 inch wheel for urasuki, but could also use my 36 inch radius platen.

Any thoughts or comments are appreciated. Thanks all!
Mark

 

Wish I could help but I have never owned one. However, I am tuned in to see how they turn out.

 

+1


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I think 36 inch radius platen is better, cause of the width of the blade. 14 inch wheel will make a too deep hollow grind.

Traditional usuba's tip is perfectly squared, your blades have the shape of mukimono.

Only my two cents...

It seems to be an interesting project! I wait to see the result!

 

Subscribed to follow the progress.

 

I have a few ahead of these, but I'm itching to take them to the grinder.
I'll try out my 36 inch platen. I've been wanting to test it out for over a year and just haven't got round to it.

Mukimono is right! I keep thinking I might square one or both off as Usuba. Not sure yet.
The hollow on the Mukimono could be a challenge, but I'll study it a bit more.

 

I have a little update on this project. I was finally able to find some time this evening to do some grinding on one of these blades.
After getting it roughly shaped as I want it I mounted up my 36 inch radius platen, which has been sitting in my tool drawer for about 2 years or so.
I love working with this platen! I used my 14 inch wheel to put the ura on the Yanagiba blades I've completed and it has worked out well. But that would have been far too deep for this wide a blade.

As you can see from the pics below the ura came out very well I think. I have a few minor things to fix in the finishing, but put to a diamond stone, the edge is pretty even. (I messed it up with sandpaper before the stone, so it's a bit scratched in places).
I used the same 36 platen to put the bevel in on the front of the blade. I still have plenty of meat at the edge so I'm not sure if I'll finish it this way, or just go with a flat grind there.
I figure the hollow will make it easier to sharpen, being less metal to remove, but it won't last forever on the stone. In the end it will be flattened with grinding over time on the stones.

Anyway, a few pics. Comments appreciated!

 

Blade completed. Handle Time!

 

looking good!
anticipating the handle report.

 

Looks good, how does the back look? 36 inch platen work out well?

 

It did work well I think Matt. Here is the arc.

 

I can't believe I never posted the handle on this one! It came out really nice! ...then I messed it up... Beautiful piece of ironwood too.
Dinged the handle doing some cleanup grinding. What can you do. My loss, your gain.

I'm offering this one up for sale at a bargain, for someone who doesn't mind the blemish.
It is also in a pretty raw state as far as sharpening, so needs some work on the stones to get the blade in order.

First $125.00 get's it plus shipping.

 

Whoa.... nice indeed.

 

Beautiful!!!

 

top notch. Beauty

 

sucks about the handle nick nice knife anyhow and now you know how fun the big wheel grinder plattens are i use the heck out of my 48" one day maybe i ll add a 36

 

Thanks Butch, and everyone. I do like the radius platen, and am thinking about making more myself to get more range.
I think I can do it on my grinder, just by fastening the stock out the distance of the radius I want, and grinding the face against a flat platen. Just have to keep the angle straight and it should produce a trued up platen.
I haven't worked out how to do that just yet, but it shouldn't be too difficult I think. I can rough it pretty close by hand, then fasten it for the final few passes and then get it heat treated for hardness. Might also be a good way to reface it occasionally.
It may not be as perfect as a machined piece, but then again it probably will be. And significantly cheaper.

Thanks for the comments all! It looks like this knife is spoken for.