Argus cutter replacement status

[wolfriverjoe 1,340]

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Purely out of curiosity can anyone point me to somewhere that shows details of how the Argus cutter and Cypres cutters work? .

Here's a decent analysis.

I got it off dz.com recently but with all the Argus threads, and URL's not perhaps searching fully, I can't find it again. Wasn't even showing up in web searchs. MJOSparky or someone posted a bunch of links to all sorts of Argus reports & bulletins.

The Polish report into the Polish fatality also has some close up pics of the inside of the cutter.

Thanks that is exactly what I was looking for. I don't fully understand the point of cutting the loop in two places rather than one but am happy that as with most things there are compromises and valid logic.

It also explains why someone mentioned (in a thread some time ago) why having a rig with the cutter at the bottom wouldn't lock closed (don't remember the brand but it could have been a Racer).

I'm not trying to be snarky, but it would have to be a single pin (pin located at the top) for a bottom mounted cutter to be unable to lock the reserve container.
The pins are on the bottom of a Racer, the closing loop goes all the way through the reserve contiaer, from outside the top (where the pop-top is) to outside the bottom (where the pins are). During a reserve deployment, the closing loops need to slide through (and out of) the cutter for the pilot chute to launch.

The Wings is a single pin (top located) that puts the CYPRES cutter at the bottom. The reserve can deploy properly without the reserve closing loop having to move freely through the cutter.

"There are NO situations which do not call for a French Maid outfit." Lucky McSwervy

"~ya don't GET old by being weak & stupid!" - Airtwardo

[skydiverek 54]

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Purely out of curiosity can anyone point me to somewhere that shows details of how the Argus cutter and Cypres cutters work? .

Here's a decent analysis.

I got it off dz.com recently but with all the Argus threads, and URL's not perhaps searching fully, I can't find it again. Wasn't even showing up in web searchs. MJOSparky or someone posted a bunch of links to all sorts of Argus reports & bulletins.

The Polish report into the Polish fatality also has some close up pics of the inside of the cutter.

Here are the attachments (bottom of this page):

http://www.pia.com/TechnicalSpecialPage.htm

[skydiverek 54]

For a refresh - here is my translation of the key points from the preliminary report on the Polish fatality with Argus in 2009: (The final report is completed, and is being officially translated into English now).

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3817893#3817893

[venturead 0]

After reading the articles on the PIA website it seems reasonable to me that the cylindrical design of the cutter may be the cause of the incomplete cuts in Texas and Portugal.

Can anyone tell me, has Aviacom changed the cutter design starting Sept 2007 to a chisel/anvil to make that a superior cutter or are they simply hoping a new batch of the same design with tighter tolerances will be the magic bullet?

"You can't skydive if you are sitting on the couch at home."
Richard "the C" Eddy

[Unstable 8]

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After reading the articles on the PIA website it seems reasonable to me that the cylindrical design of the cutter may be the cause of the incomplete cuts in Texas and Portugal.

That's A Bingo!

I think this is pretty simple ~ Cylindrical design, loop cuts unevenly across the Cylinder, and that is a stuck loop. A wedge, spear, or pointy thing on the end would solve the problem.

Another point: I do not believe the folks that made and tested are Argus are stupid. I've seen varying reports of acceptance testing between 2%-5% of all cutters, with tension between 0 pounds, all they way up beyond any rigger would close a rig. I have a hard time believing in all of those acceptance reports and all those batch tests, not ONE exhibited an incomplete cut. To see this level of quality conrol not identify a problem that is common knowledge already.... unlikely.

=========Shaun ==========

[skydiverek 54]

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After reading the articles on the PIA website it seems reasonable to me that the cylindrical design of the cutter may be the cause of the incomplete cuts in Texas and Portugal.

Vigil cutter also cuts in two places, yet we do not see the problems with it.

[piisfish 135]

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Vigil cutter also cuts in two places, yet we do not see the problems with it.

//joke mode// 'cause it's already the 5th version of the cutter //*joke mode off//

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[VincePetaccio 0]

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Thanks that is exactly what I was looking for. I don't fully understand the point of cutting the loop in two places rather than one but am happy that as with most things there are compromises and valid logic.

Halving the pressure on the closing loop at each point of contact doesn't seem to make sense to me, either, especially for such an obviously critical component of the process. ::shrug::

Come, my friends! 'Tis not too late to seek out a newer world!

[bofh 0]

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Thanks that is exactly what I was looking for. I don't fully understand the point of cutting the loop in two places rather than one but am happy that as with most things there are compromises and valid logic.

Halving the pressure on the closing loop at each point of contact doesn't seem to make sense to me, either, especially for such an obviously critical component of the process. ::shrug::

On the other hand it sheers the loop off (which usualy takes much less force). Ie compare the force of pressing a knife against an object compared to cutting it with scissors.

[Skybear 0]

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On the other hand it sheers the loop off (which usualy takes much less force). Ie compare the force of pressing a knife against an object compared to cutting it with scissors.

But this only works if you have two sharp edges, like on scissors. On a cutter, the loop hole does not provide a sharp edge. Otherwise the loop could be easily damaged by the loop hole during normal operation.

[VincePetaccio 0]

I suppose a good analogy for the design would be using two knives on a cutting board instead of one, and cutting with the same total force.

Come, my friends! 'Tis not too late to seek out a newer world!

[bofh 0]

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I suppose a good analogy for the design would be using two knives on a cutting board instead of one, and cutting with the same total force.

Not really. Even if one side isn't sharp, the loop is still sheered off (in two places) and I expect the force to be lower than forcing a knife down against an anvil.

Ff the cutter had one side up and another down and the holes were not parallell, then even more force would be used to cut the first part of the loop. On the other hand, riggers would mount the cutter upside down now and then. (and it would only work on rigs with the cutter on the bottom).

[sundevil777 93]

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I suppose a good analogy for the design would be using two knives on a cutting board instead of one, and cutting with the same total force.

The argus design cuts by shearing, very different than a knife coming down against a flat surface.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[VincePetaccio 0]

Shearing against what, the hole in the cutter?

Come, my friends! 'Tis not too late to seek out a newer world!