Maybe max out a standard house oven and slowly bring it down over 12 - 24 hours; after getting the billet nice and warm first ?

Crushing defeat.
 

 
There was a slight bend in the knife.  VERY slight.  Figured a slight bend would get it back again, but a catastrophic failure happened. 
 
One the bright side you can see the spherical carbides in the knife 

 
R.I.P:

 
 
In any case I did a quick etch to see what the spring pattern would look like:

 
again, this was a QUICK etch.   didn't sand it or anything.
 
 
I did put the end on the belt sander to see the quick sandwitch pattern, which you can kind of see:

 
over a week's work down the drain in an instant.  I got one more shot at this with existing materials.  

OUCH!!!  I was afraid of the brittleness when you stated how hard it is. You might want to temper it a little, maybe oil quench then a temper.  I do not know what the spring steel is, but a slight temper would bring your hardness down a notch and a little less brittle. And yes the cross section looks sweet you got the two to go together very nicely!
 
Maybe play with your broken pieces as a couple of temps/times to achieve what you would like.

So.. can we agree that the slight bend you experienced in the steel was.. a learning curve?

Scarlet-Tech
So.. can we agree that the slight bend you experienced in the steel was.. a learning curve?

Scarlet-Tech
So.. can we agree that the slight bend you experienced in the steel was.. a learning curve?

1.25" total OD is not enough to make the chopper sadly:

 
but it is plenty big enough for the fighting knife

 
1.5" diameter is the desired OD.
 
 
 
 
 
 

Nate, 
 
I would be interested in an 8 - 10 inch chefs knife.
 
Lets talk about it 

Birch burl on the left, unknown burl on the right.  

Getting some handle scales stabilized for the next group of choppers. 
 
 

looking forward to your next update

Here is the next evolution in the spring steel wrapped tool steel billet:
 

 
Adding a layer of invar (nickle/iron).
 
I am hoping it will add some "chrome" to the knife in certain area's.  Nickle will resist the etching so when the knife is etched, there will be bright spots (I AM HOPING) inbetween the springs, so perhaps a zebra appearance?  Only way to know is to try it.
 
Getting that spring on there is not an easy task, especially with now an additional layer of material.

Used some 550 paracord to wrap it and hold it in place while I basically "screw" the spring onto the shaft.
 
Done:

 
Leaving the top of the spring on gives me something hold onto.

 
Then the ends are welded.... and most importantly, trued up on the lathe:

 
I true them up so that when I stand the billet on end in the press I get a perfect vertical crush.  I plan to video that over the weekend.
 
 
 
 

I am home.  Sending you a PM Nateman.. 

Now, like I said more good news.  My epiphany...
 
Every knife maker needs a grinder.  Problem, is they cost LOTS of money.  (around $1K).  I never had any intentions of buying one, when I can make one.  However, I already have a benchtop machine that I already own.  A 4x36 belt grinder.  
 
It never was long enough to flatten billets to put them on the CNC, so I came up with the idea to "extend" it so I can sand a solid 2" long billet with semi precision.
 
The sander comes apart (with the help of a dremel tool) in 2 parts.  The machine itself with the motor, and the belt sander part:

 
 
All I have to do, is reproduce this part:


 
Nothing more then a flat portion, with some angle iron spot welded (or drilled and tapped) to it.  I can use a precision ground top as the surface, and those 4 holes bolt to the mating surface of the sander:

Some extra supports may be required, but when you have a CNC, I can bang one out in short order if the need arises.
 
 
I should now be able to flatten out 2' long billets of material.  I know it will probably put extra strain on the motor, but I have much larger motors laying around and could retrofit something should the need arise.  I will just take it easy pressing the billet down and it should be fine.  The motor has thermal mechanisms in place in case I get stupid.
 
 
 
 Said modification should cost less than $100.00  The most expensive part of the attempt will be the 4" x 24" of precision ground 3/8, or 1/2 stock for the platen. 
 
 

Nice, Nate!

The nickle added spring steel wrap is finally on the machine: