Virtual BBQ WIP. GNiCr40Al4 frame lock folder.

Joined
Oct 20, 2008
Messages
5,547
Hello all you excellent BladeForumites out there. Come one, come all to the Virtual BBQ. We have marvelous makers with masterful methods melding materials, hillbillies hucking hawks and hooting 'n hollerin' at this hoedown, and a rag tag band of miscreants making acoustic music for the masses of party goers. Just smell that good food in the air, hear the hammers beating steel and grinders snarling and abrading. Welcome. This is SHOPTALK.

My humble contribution is as follows. If anyone has comments, questions, or a better way to do something (likely) pipe right on up. Enjoy!

Several months ago, a BF member from China who goes by "hammerfall" sent some samples of a new blade alloy to some makers on the forum. We were to make knives of it and return some feedback. At long last, I'm using my chunk.

It's called GNiCr40Al4. That's a Chinese alloy designation, it's 54% nickel, 40% chromium, and 4% aluminum. The remaining 2% I believe are trace proprietary ingredients, perhaps some TI, don't know what else. No iron. It was used in Soviet nuclear submarine bearings and such, cold war tech stuff invented by the Russians.

It's supposed to be very tough, VERY corrosion resistant, and it age-hardens (precipitation) to 57-58 Rc, at which point it should be highly wear resistant. Yeah sure, I'll take a free sample to try!

This will be a frame lock folding knife, the lock side being .160 6Al4V titanium, the obverse being a toxic green G10 scale and TI bolster over a 410 SS liner.

Here's a pattern made from white acrylic. I used it to scribe out all the major pieces onto the raw materials.

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I made a card stock scale/bolster pattern and cut them out to scribe the bolster and scale. Since the bolster will be dovetailed with the scale, I added 1/8" extra length to the front of the scale when cutting.
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The GNi cuts OK in it's unhardened state. Not like butter, though. About like the titanium does.
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Looks super great already, huh?
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On the table in the grinding room, a batch of 52100 hunters with various grinds, tangs not yet tapered...
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After rough cutting everything, I went and profiled right down almost to the line on everything. I left a little for adjustment.
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I dropped the liner into the spark bucket. Ew, freezing chunky tainted grinding water up past the wrist. Love it when that happens.
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The G10 (from AKS, like most of this stuff) was 1/4" thick, a bit hefty for a folder scale. The bolster is .160 stock, and I'll want a little palm swell in the scale, so I milled it down to .187.
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I flattened it further on granite with paper.
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The blade stock was a rolled out bar of uneven thickness. It was thinnest near the heel of the blade, so after clamping to the mill table, I lowered the 4 flute HSS end mill until it was lightly cutting the heel, then traveled with several passes and plenty of oil at slow speed and feed to flatten half of the blade, then with the cutter still locked in height, re-clamped and cut the other side flat. This stuff mills OK too, just slow with HSS.
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I ground the milled surface, then flipped the blade and milled the other side. Finished thickness ended up at .135. A little thinner than I'd first projected, but fine all the same.
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This is fun. I haven't made myself a knife in a LONG time. And, I like the materials on this project.

Stay tuned, some drilling and grinding, etc. coming up next time I can spare a few hours.

Now, I'd better get over to that bowl of chips before Sam and Stacy eat them all...
 
I'll be following this one closely. :thumbup:
 
Cool, guys. Nathan, please do mention if you see anything I could do differently with the mill, I'm no machinist.
 
I've already learned to consider clamping stuff to the table of my little mill instead of always using a vise.
 
This is great Salem. I'll keep an eye on this. A folder is next on my list to challenge myself.
 
Next I drilled the pivot in the blade. Since I don't have a 3/16 transfer punch (on the list) I used a 3/16 drill bit spun by hand through the pattern hole to mark the pivot location on the blade. I did the same with the lock side of the frame. I then carefully center punched on the marks made by the drill point.

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I drilled the pivot on the mill, as the spindle is nicely square to the table. First I used a #1 spotting drill for accuracy, strong light, and the XY table to zero in on my punch mark. The bit was running, and I looked from several directions to make sure it was centered, then drilled until I began to hit the c-sink.

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I didn't move anything, just replaced the spotting drill with a #14 cobalt drill bit. This is undersize for 3/16, just enough to ream for a good fit.

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I used a 3/16" HSS chucking reamer to clean the hole to size. I couldn't find my older chucking reamer, so I cut down a new one. I used an angle grinder to cut the top of the shank off, shortening it to a less flexible length.

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I clamped the TI frame and SS liner together with the frame on top. I then used the same procedure to drill and ream them for the pivot. I took the SS liner away, stacked the frame on top of the bolster piece with the edges aligned, clamped, drilled, reamed.

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I took the bolster away, and flipped the frame piece for counter boring. I used the 3/16 reamer to locate the pivot hole, then swapped it for a 9/32" cobalt drill bit. I drilled down into the pivot hole with it, stopping with appx. 0.030" left before breaking through. This is about the depth the back of the pivot will sit flush.

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I swapped the drill bit out for a "L" HSS chucking reamer, also with a cut-down shaft. This reamer is further modified by grinding most of the taper off of the tip, leaving only .020" or so of taper at the end, just enough not to bind. This enables me to reach the bottom of my drilled counter bore. I reamed the 9/32" counterbore to the bottom with the modded "L" reamer. This allows a light press fit for the pivot pin.

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I did the same with the bolster. Then I realized I'd bored the bolster from the wrong side. So, I had to go scribe and cut out another bolster, re-drill and ream it, then bore it from the right side. Whew. Dumbass.

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I pressed the pivot in. It'll get ground flush later.

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I put on a Nylatron washer, put the blade on, another washer, and the SS liner and bolster. Since the male pivot head is the same diameter as the female pivot head, I used the little grinder and a 220 belt to lightly remove a little material around the edge of the pivot screw head. This way it's free to turn for assembly and adjustment.

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They fit OK, I took it back apart to cut the pivot length down. I used the bandsaw, then deburred and cleaned the cut up to 220 on the little red grinder. Now the top of the barrel was just below the bottom of the bolster counterbore on the assembled parts.

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I put it all back together and took a few mock-up shots.

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That's it for now. I talked to Brad Stallsmith at Peters Heat Treat today, I will be sending them the blade for age-hardening. Cost will be the same as a regular single-blade order, so quite reasonable.

More to come when I can. Thanks for looking! Now back to the party. Hey Kentucky, want to pick some banjo? Do you know "Whisky for Breakfast?" In G, of course...
 
Nice Salem! I'll be following this one. Can't believe I missed it until now. That looks like it's gonna be a sweet little folder. You deserve it!:D
 
Neato! I like that shape a lot. I've got a few folders drawn, but don't have the inner workings conceived yet...
 
Hey Kentucky, want to pick some banjo? Do you know "Whisky for Breakfast?" In G, of course...
Nope. but if you can hum a few bars I may be able to fake my way thru:D:D
Nice work man, Id love to try my hand at a folder..Ill watch this close..
 
Thanks guys. Here's some more.

Let me preface this by saying- in case any of you find the level of detail tiresome, I'm trying to document this in such a fashion that a beginner could build a framelock by reading it. So, a folder maker may find this redundant at times. Just increase your scrolling speed if this is you...

Making the backstrap was next. I put the blade on the pivot, and traced the edge with a pencil where I wanted the spacer to be. I penciled in a radius at the top of the spacer where I wanted it to end.

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I set the calipers apart the distance I wanted the screws from the edge, far enough or the head to sit in it's counterbore next to the chamfer at the edge. I scribed a center line for the screws.

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I took a piece of tracing paper and traced the backstrap mark off of the frame. I cut it out.

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After considering several colors for the basckstrap, including blue and even pink G10 (how 80's would that be) I decided on black for a "Mr. Yuk" color scheme. I took my sheet of .185 black G10 and knocked part of it down to .168 on the mill.

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I spray glued the tracing onto the G10, cut the backstrap and a round pivot spacer out of it.

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I then sanded them down to .163 on granite. .163 is the thickness of the blade with the washers (.015 ea.) added.

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I took the Ti frame piece and a #43 cobalt twist drill (clearance hole for 2-56) and drilled the three centerpunched holes for the backstrap screws.

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I flipped the frame and counter bored with a #19 bit, for the screw heads to sit down in.

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I super glue tacked the backspacer to the frame, then used the holes in the frame to drill clearance holes with the #43 bit through the backspacer.

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I took the spacer off, then clamped the SS liner to the TI frame. I used the #43 bit to mark through the frame holes onto the liner.

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I drilled the liner holes with a #51 bit, then tapped them with a HSS 2-56 tap. I used the hand tapper I made from an old drill press. The top pulleys have been removed, and replaced with a flywheel and crank.

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The spindle has a coil spring that can be set for downward or upward pressure of varying strength. The tap is merely chucked in.

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The screws needed to be trimmed for length, first with a nipper...

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Then ground flush. Note the use of the G10 pivot spacer. It's much more convenient to have in there than the blade for many steps.

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The blade is centered in the handle, and the spacer is good for now.

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I marked out where the screws will be in the bolster.

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Drilled with #43, c-bored with #19, marked through, drilled the liner with #51, and tapped, similar to the backspacer assembly. I cut screws to length.

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The knife as it is now, with the bolster and backspacer installed. Stay tuned! Thanks for watching.

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