C96 Cutaways

[sheepherder]

Both Gerben and Peter posted links to amusing 'cutaway' C96 Mausers over on The Other Forum...very interesting...

I've been trying to figure out how I would split a C96 in half. Band-sawing it is one way, I suppose, but many parts in the C96 are handened...

Milling it down would work, same problem again, and it would waste half the display...

My final solution would be to set it up in a Wire-EDM machine and let a small diameter wire run right through it...That would give you two nice halves.

Alternately, an industrial Laser could do it too. In both instances, things like coil springs would need to be removed. Grips too.

An interesting mechanical exercise...

[Olle]

Laser might work?

[sheepherder]

Originally Posted by Olle

Laser might work?

I've seen on The Science Channel/How It's Made that Lasers and plasma cutters can be dilated to a thin beam and complex shapes cut out of steel plate, but I haven't seen anything thick or variably-thickness/stacked layers like the C96 cut...

Because of the variation in thickness as the Laser or plasma beam goes along, I'm guessing that a constant feed-speed wouldn't work...

And a thin/large diameter grinding/cutting wheel would heat up quickly and leave heat scars...Maybe with water-cooling???

Surface grinding would do the job, but again, you'd lose half the metal...

[sheepherder]

Here's the scrap piece left over after Wire-EDM'ing a 9mm magazine tunnel in a piece of five inch thick metal...

The wire itself is only .016" dia...Very accurate cuts from an experienced operator...

[Olle]

No, the laser was mostly a joke. Wire EDM works though, but I figure there is a chance that parts can come loose or move as you cut so you would probably have to do some of them separately.

I have had several parts cut with wire EDM, and it could be an expensive proposition as they charge per cut length x cut depth (ie: the area of the cut). For example: One part they made cost me $7 ea for a cut approx. 1" long and 1/8" deep, excluding setup and material. Looking at the pricing for other parts they have made, I figure the average is roughly $50-$60/square inch, so you have several hundred dollars worth of cutting in a C96. I did shop around, but the price I got appeared to be the going rate. You would also need multiple setups, and this will add to the cost as well. Water jet could possibly be an option, but I don't know if it can handle a cut as deep a you would need in this case. Somebody posted a cutaway on a gun forum not too long ago, and it was done with wire EDM. I believe the guy worked in a machine shop though, so cost was probably not such a big issue. I figure an affordable job would have to include sweet talking, after hours, off the books and a case of beer.

Of course, you could accomplish this with a milling machine as well, but like you suggested, the neat thing about EDM is that it will yield two cutaways. IIRC, the cut is in the 5-10/1000" range so it doesn't remove much material at all. Another thing to consider is that the EDM leaves a somewhat rough and discolored surface, almost like a fine sandblasted or etched finish. This would work great if you want to paint the cuts, but you would have to polish the parts on a granite plate if you want the steel to show like in your picture.

[sheepherder]

Originally Posted by Olle

I figure an affordable job would have to include sweet talking, after hours, off the books and a case of beer.

Yes, any EDM is slow and also messy (the electrolyte solution). There was a famous thread on the Roderus Forum of a member making an AR-15 receiver out of a solid block of aluminum. He used a CNC Workstation, a 1/4" ball end mill [IIRC}, at 10,000rpm removing .006" at a time and the machine ran all night doing one half at a time. If it was done during work hours and at shop rates it would not be cost-effective. Wire-EDM is similar in practice/cost. My mag tunnel was a simple cut and I supplied the work drilled for the wire to be inserted and all dimensions, tolerances, and clearances. The shop ran it after closing and when they came back in the morning it was done. I did two, btw. And it was expensive. I'll drill & broach next time.

Another thing to consider is that the EDM leaves a somewhat rough and discolored surface, almost like a fine sandblasted or etched finish.

Yes, a satin finish. Acceptable for interior surfaces, not so much for outers.