RJ Martin - Devastator

[David1967]

Just got this one from Les Robertson:

David

 

[dialex]

Nice Scarab
Now seriously, I only have three words to say about the Devastator: "Beau"-"ti"-"ful".
Outstanding manufacturing and great design. Specs please?

 

[David1967]

Blade 11 cm, open 24.3 cm, closed 17.5 cm...

For more info go here:

http://www.robertsoncustomcutlery.com/martac.htm

 

[Danbo]

As soon as I leave the Govt building where I work, my Devastator goes into my pocket. Mine looks very similar, except mine has orange/black G10 overlays.

 

[Chiro75]

That looks like it will probably be able to cut stuff.

 

[Danbo]

I imagine they're all about the same, but mine has one of the thinnest, sharpest edges I've ever seen on a knife.

 

[rdangerer]

Hey, ya'll who own one of those Devastators... that finish on the blade. Looks like CNC milling machine tool marks that RJ leaves on the blade on purpose for interest... I take it you can feel those with your finger or finger nail, true? They are tool marks, true?

How do you like the effect, the finish overall?

(RJ does indeed hollow grind thin and delivers the sharpest edges I've yet experienced... super wicked hair jumpin'. I don't think anybody beats his initial sharp edge... a few get close)

 

[Danbo]

Yes, those marks are made with a milling machine, and are deep enough to easily feel with your finger.

 

[dialex]

I thought it's a belt grinder with a coarse texture that leaves those marks on the blade. OTOH, this kind of finishing is not only eye appealing but also useful. I think those "microserrations" help cutting.

 

[David1967]

The microserrations end about two mm from the edge so IMO they do not really help cutting. But the knife is quite sharp anyway...

David

 

[GarageBoy]

RJ Martin has said before on the "other" forum that it's 80 grit on a belt sander

 

[Danbo]

R.J. told me in Chicago that he used a milling machine.

 

[SharpByCoop]

Yup, it sure is a job for a mill and a *VERY* savvy programmer. You can see the pattern on the endmill traverse in this closeup I did for Les and Randy. I suspect this 'grind' and setup takes longer than by hand.

Coop

 

[GarageBoy]

Holy crap. I have a $3000 CNC mill sitting in my dad's room (making his large format camera back patent) that I can't even program to cut 2 rectangles. (The sad part is my dad is expecting me to be the programmer)

 

[golok]

Certainly, a lovely piece of work.

 

[David1967]

Yup, it sure is a job for a mill and a *VERY* savvy programmer. You can see the pattern on the endmill traverse in this closeup I did for Les and Randy. I suspect this 'grind' and setup takes longer than by hand.

Coop

It looks like you took pictures of the actual knife I bought from Les...

Nice closeup.

David

 

[tknife]

Awesome! RJ's knives are known for being laser sharp, and those milled grooves look so cool. Great score.

 

[rdangerer]

Wow... excellent close-up pic by Coop.

Absolutely first rate programming to get the mill to stop at the top of the grind, move right, leave the perfect ridge down the middle, and leave a "maze" like pattern. Even more difficult is the radiusing of the mill around the corner that would be the plunge area.

Very cool in close-up view. Thanks to Coop for the excellent high rez pic.

I appreciate the technique more in close-up than from afar. (Obviously I haven't handled one of these).

That's the neatest piece of machining I've seen since Michael Walker described how he does the wire EDM milling to mate the wave patterned blade halves together on his outrageous knives.

 

[RJ Martin]

Thanks for all the interest and kind words. Jim Cooper-Thanks for proving once again that a picture IS worth a thousand words.

Yes, those are CNC machining marks left by a ball endmill that ran in my CNC, from my program generated from my 3D design. I leave them on the blades of some of my knives because they are visually interesting. They seem to have no effect on cutting, and, since they don't run to the sharpened edge, aren't considered serrations. Because the blade was machined, under flood coolant, it has far less residual stress than a ground blade. I can see the benefits in the consistency of the heat treat.

It is more costly in both time and material to do this, as I use a brand new carbide endmill on each side of every blade, but, I like the results very much.
And, I can always regrind the blade after HT, should I desire a smooth finish.

Stay tuned, because I am just getting going with this machining thing........

 

[dialex]

Thanks for the close up Coop. Compliments to all involved in the making of this outstanding (to say the least) knife.