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pchapman

Firing a CYPRES cutter as a gun with no anvil (and internal cutter photos)

By pchapman, in Gear and Rigging

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pchapman    262

pchapman
Everyone's talking about AAD cutters these days so I cut open an old Cypres cutter with a dremel tool to get some photos to share.

Then the cutter was fired at a target. For that, an expired Cypres and 5 year old battery were used, plus a plastic bag and vacuum cleaner to provide the "altitude and freefall" for the Cypres.

BAM! Impressive noise and sparks.

Without the anvil to keep the explosion internal, in effect I had a little sawed-off Cypres gun. About 20 cal. The cutter projectile measured .197" dia., or 5.00 mm.

Video at:
http://blip.tv/file/5027093
(The site was a little flaky for me after uploading, so I'll repost elsewhere if there are problems. It may help to click "Select a Format" and pick the mp4 version.)


Paper on the table next to the cutter was torn up and blackened from the firing.

Two feet downrange, the cutter blade first punched through an inch of insulation foam that I had there just in case of any rebound, making a small entry hole and a bigger exit wound. No spin stabilization on Cypres cutter blades...

It then dug its way to the back of a 1/4" of plywood, lying somewhat sideways, and making a dent in the 2 by 4 behind it. Without the 2 by 4 the cutter should easily have gone through the thin plywood.

None of this proves anything about cutting spectra loops, but I haven't seen any such tests ever being done and it was quite impressive!



Other notes:

Just remember in the photos that I was using the dremel tool by hand, so it wasn't one big clean cut across the cutter. I also filed the cut edges a little before handling & taking photos. Rough edges are my work and not Airtecs!

The plastic sleeve was taken out in most photos but one can see it hacked up in one shot. The sleeve isn't hard plastic but is fairly rigid (not like soft silicone slider bumpers).

The photos show the quite thick cutter housing, with the sleeve (brass?) at the end that provides a smooth entry hole for the closing loop, with space for the plastic insert as well. There's the single horizontal cutter blade, which is sharpish to the touch but has a wide angle and isn't sharp in the same way as a knife blade. The anvil end of the cutter is quite long and solid looking.

I made sure to get shots in focus!
Wish others could do the same, for there have been some lousy, fuzzy photos taken from too close or too far away in some of recent cutter related investigations.

Last year I did a similar "inside the Cypres" post by taking photos of the disassembly of a Cypres 1. (http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3785900;)

In that thread, Erdnarob also mentions intentionally setting off a Cypres cutter on the ground, but he did it with capacitors. I tried the simple way first, with a battery, but it had no effect. Seems like the high flow from a capacitor is needed. I played with one but didn't get the cutter to fire; likely the old capacitor was bad. Next came the bag & vacuum cleaner which worked.

Thanks to Andre Lapointe who donated his expired Cypres to me a couple years back.


Now we can solve the AAD debates by having cutter duels. Twenty paces, turn and fire!

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1969912    0

1969912
Quote

Fun!

What should I do with the unserviceable (type 1 with damaged plastic insert) Vigil cutter that's sitting in my closet? Ideas anyone?



Stick a piece of steel rod that just fits through the closing loop hole, then fire it and see what happens. Put some armor around it in case the housing bursts. Post video.

"Once we got to the point where twenty/something's needed a place on the corner that changed the oil in their cars we were doomed . . ."
-NickDG

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pchapman    262

pchapman
So Brian, or anyone with Vigil cutters, let's see how they do on 4 closing loops together, zero tension. That's what I tried today with my last spare Cypres cutter.

(Presumably you don't have a spare Vigil lying around so you'd have to figure out a battery and/or capacitor method of firing.)

I wanted to test its performance when jammed with Spectra, since it is in some ways tougher to cut than stiff metal. With a lot of force, 4 closing loops could just be pulled through the cutter. They were all old loops removed from rigs in the last year, so there probably was a little silicon still left on them.

Here the cutter met it's match. Three of the loops were cut cleanly but the fourth got stuck. Almost all was cut, but one bundle of fibres wasn't, having been pushed to the side of the cutter blade. (Where each Cypres loop can be seen to be braided with multiple 'bundles' of fibres.) One can slide the loop back and forth from either side, so the fibres aren't cut at all.

I figure that with the hole packed full, as the cutter hits, some Spectra gets squished and forced out to the side. Just a little bit is able to flatten out enough to squeeze into the minimal space between the cutter projectile and the steel side of the cutter barrel. That's not something that ever happens with a single loop.

Of course that's just one test so statistically speaking, who knows how many times all 4 would have been cut, vs. 3 and almost but not quite all of the 4th.

When I fired the cutter it wasn't lying quite flat on the table, but with one end of the cutter hole aimed upwards a little. The three cut pieces from that side went flying 3-6 ft, and one is still lost somewhere in a messy corner of the workshop. Who knows, that might actually be more impressive than with a single loop, because there's so much Spectra to forcefully squeeze out of the cutter.

I'll post a couple photos after the weekend.

I think the Cypres cutter still did pretty well. Everything will have its limits. We'd need at least one test of a Vigil cutter to compare, and preferably a few of each.

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skybill    19

skybill
Hi Chappie,
Isn't playing with explosives fun! When I used ta' work for Scurvyirvin just about all the chutes we built had some kind of explosives on them!! We had a walk in storage magazine behind the plant where we stored all the cutters. When a box of em' would go out of date we'd have fun pulling the pins on em' and tossing them into a steel cylinder. Most of the time they'd just fire but a lot of em, cuz the charge got unstable with old age, would blow the blade thru the top!!!! Good fun!!
SCR-2034, SCS-680

III%,
Deli-out

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BrianM    1

BrianM
Four loops, you say... I could try that.

You are correct, I do not have a Vigil handy to fire it. Well, actually I have a few rigs in for repacks right now with Vigils, but not sure if their owners would approve of me using them for experiments.

I've got lots of batteries of various voltages and capacities (up to 12V 12Ah), lots of capacitors of various capacitances, and a handful of DC power supplies (up to 13.8V 20A). Should be no problem to rig something up.

The connector on the Vigil cutter is a standard 3.5 mm stereo plug. I have no idea how it is wired. Three contacts to choose from - I guess it'll be trial and error unless someone knows which contact is what.
"It's amazing what you can learn while you're not talking." - Skydivesg

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SEREJumper    1

SEREJumper
Pretty cool! Thanks for sharing.

On a side note, if you have a normal fired cutter, DO NOT try to disassemble/cut/drill/dremel the thing open. There is still a lot of pressure built up inside and it will explode. I forgot how long you have to let it sit, but I want to say in was a number of months!

One person has already learned the hard way...
We're not fucking flying airplanes are we, no we're flying a glorified kite with no power and it should be flown like one! - Stratostar

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MikeJD    0

MikeJD
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That is some amazing work on the part of cypres. Glad I bought a C2 and not the Vigil or that other one.. argus?


Keep it up Cypres!!!



Airtec are the manufacturer/ vendor. I'm also a Cypres user, so not an Argus or Vigil apologist - but there's nothing in this thread (at least, not yet) to suggest the results from those AADs would be any less impressive.

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pchapman    262

pchapman
Quote

Quote

http://www.youtube.com/watch?v=ohBxepGxIxc



EXPLENATION: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?do=post_view_flat;post=2101957;page=1;mh=-1;;sb=post_latest_reply;so=ASC



So the video shows a UPT Micron container lock during a ground test Cypres firing.

If anyone wants to discuss that issue, lets take that to the original thread about that test, that skydiverek provided!

====================

P.S. - Regarding my sawed off Cypres cutter video-- I have now deleted it.

I had my fun with it, and this thread remains to describe what can be done with a cutter, and to show photos of the test and what a cutter looks like inside.

It isn't like it takes that much thought to recognize the implications of how a cutter acts, and to come up with a test like mine. So it can't be considered any sort of big secret.

One can't fully take back things once they're out on the web.

But it is still a reasonable course of action to not share it all around too much, to reduce the chances of anybody outside our community overreacting.

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