Very rough prelimary concept drawing. Just under 19" OAL as drawn. Will most likely use .270" thick S7 tool steel.
Concept drawing after some refinement.
Pattern on the 3" x 36" x .270" bar of S7 (along with another prototype):
Roughed-out on the bandsaw. Build Off knife is second from left.
Getting closer to profile. Second from left:
Profiled and ready for drilling:
Got the holes drilled and chamfered so she's now hanging on the pre-HT board along with a few others:
Got the bevels roughed-in last night:
I put her through a stress-relief cycle and sent her to Peters for heat/cryo treating with a small batch of other knives. Now time to figure handle materials . . .
Black paper micarta and stabilized amboyna ready for mating after being rough cut on the bandsaw.
Scale materials mated, epoxied, and clamped.
Back from Peters' Heat Treating, and not a moment too soon. I have 14 days to finish this, along with a quite a few other projects that need tending to. My daughter took a liking to it because of the pretty colors from the hardening/tempering process. When I told her that I needed it for a photo she said, in a very matter-of-fact tone, "you can just take a picture of it while I'm holding it".
And after she finally relinquished it.
Fullers ground into the sides of the tang in preparation for tapering:
I frequently get asked about this fuller in the tang as well as about tapered tangs in general.
Removing material with a wheel is far more efficient and creates much less heat than using the flat platen. So it's common practice to remove steel first with a wheel, then flatten the tang against the flat platen. Lots of makers use this same technique with large flat grinds - remove as much steel as possible with a wheel and then flatten the bevel on the flat platen. I do all of my tang tapering, and a good bit of bevel grinding, after heat treat, so it's very important to avoid overheating the steel so as not to affect its hardness.
As to the benefits of tapering the tang, as well as distal tapering of the blade:
To me, it's less about the center of mass (balance point) and more about how that mass is distributed. As an illustration, let's say you have a 3-foot staff that weighs 5 pounds. You then put one 5 pound weight on each end of the staff. You now have a 15 pound staff with a balance point in the middle. Now slide your 5 pound weights to the center of the staff. You still have a 15 pound staff with a balance point in the middle, but it will handle much, much differently. This is obviously an extreme example, but the same forces are at play with knives. The larger the knife, the more important mass distribution becomes, as well as it's affect on the Center of Percussion (aka the "sweet spot").
Tapering the tang:
Tang cleaned up and blended into the flats:
Hanging on the HT board with a few other projects:
Ground the edge at a 45 in preparation for finishing the primary bevels:
Some finishing passes on the rotary platen with a 65 micron belt:
Time to drill the amboyna/black paper micarta scales. I measure the thickness of the ricasso and the butt of the tang, then subtract the latter from the former and divide by two. That gives me 90 thousandths, which is the thickness I need to shim the butt of the scales in order to drill perpendicular to the centerline of the knife.
Scales have been drilled, rough cut on the bandsaw, and then roughed to shape on the grinder. They're now dry-pinned to the tang and ready to be ground flush.
Once the scales are ground flush I clean up the perimeter by hand.
Start shaping with the 10" wheel.
More shaping with the 2" wheel.
Then finally the 1" wheel is used to get into the tight areas.
After the 1" wheel I begin blending the facets with a slack 1" scalloped belt followed by much hand sanding.
I lay out my lines for the top grind. Empty Mind Time.
Cleaning up the top grind with finishing stones after roughing it in on the flat platen.
3/16" holes counterbored to receive 1/4" copper corby bolts.
Epoxied and clamped for the night.
I failed to seat the corby bolts low enough which resulted in grinding through to expose the inner cavity of two of them on the female side. The plan is to open up the pockets to .125" and press fit/glue copper rods into them.
Bolts drilled and rods press fit/glued into place.
Rods ground flush and the handle is ready to finish. She feels good in-hand.
Handle finished and tang marked.
Finished. Click the photo below to see more shots and specs.