WIP: Beech and Bone Ko-Tanto

[TrevorWalsh]

So I found out that the sculpture workshop I was going to start forging in will have to be delayed another week, Safety Orientation's fall the day after the open work days. It's a bummer, because I run a shop as my day job, and have given likely a similar safety talk several times a semester to the new students. Oh well, the idiosyncrasies of shops.

 

Since I can't forge down the kitchen knife shapes I wanted I thought I'd start on a pair of the ko-tantos in the attached sketch. After reading Dave F.'s stuff on the Crossed Heart Forge website over and over, I think I know what I need to attempt.

 

 

I made a brass kata, from some thin stock and used that to mark out the 1084.

 

The two were adhered together temporarily, drilled, milled and profiled. I am doing this at work after hours, and as long as I had the mill it would be a quick way to rough the mune (spine), nikago (tang) planes parallel to one another and have a nice square munemachi (step down to nikago from the spine side).

 

 

Finish profiling with the disk sander and separate.

 

 

I cleaned up and flattened the faces on a 500 grit stone...

 

 

Then began work on setting the iori-mune (house roof spine shape), tapering and roughing in the hira-zukuri (full flat grind) shape.

 

 

And that's it for tonight. I'm bone tired and ready to go sleep.

 

 

 

 

 

[Justin leonard]

Awesome milling machine man

[DaveJ]

how is this project going? nice looking "classical tanto tip" shape, starting with a kata is great.

you might want to taper the tang profiles a bit to help with your handle carving:

 

http://islandblacksmith.ca/tag/tanto-geometry/

[TrevorWalsh]

Thanks Dave, alot of what I've been thinking of comes from the design articles on your site, your discussion of the Aizu Shintogo kata. I have some more photos I have to get up of this blade in progress... When you say "taper the tang profiles a bit" are you refering to the distal tapering from the habaki area to the end or from the nakago-no-mune to nakago-no-ha? Both?

[DaveJ]

...i think i meant a wee bit more taper from the side or "profile" view, so that you get a firm registration without any play as you carve inside the handles...

 

but yes, along the other two axis as well; the nakago-no-mune should have a distal taper and from the nakago-no-mune to the nakago-no-ha should taper at the same angle as the blade bevels do...

here is the specific one on those details, with photos: islandblacksmith.ca/2014/06/classical-tanto-geometry-nakago-tang/

 

...but get those photos up, you may be way ahead of me on this already... ^__^

[TrevorWalsh]

Thanks for holding my hand with this Dave, here is the photo of the blade in progress against the kata. There is a more pronounced taper than in the kata. I think I reground the profile because after the distal taper, and blade bevel tapers, the nikago-no-ha itself had a distal taper, which in your geometry primer say should be of parallel thickness.

That seems a simple way to drive and constrain the various planes and tapers involved. So how am I doing?

 

Edited July 8, 2015 by TrevorWalsh

[DaveJ]

yep, i find that is the best way to think about it:

 

(start with a classical/antique kata)

profile/outline the tang,

then bring the bevels back from the blade so that the nakago-no-ha is the right thickness all the way along,

and then the distal taper of the tang has already established itself for the most part...