johnmatrix 21 #1 March 30, 2011 Hi all, I'm just wondering, what is going wrong with the Argus cutters? My understanding is that both Argus and Vigil have a circular cutter design, yet I have not read any stories of Vigil cutters failing to cut the loop on activation. Are the Argus and Vigil cutters exactly the same? Does anyone know of any difference in construction or materials used? Anyone care to offer any theories? I'm just curious. Quote Share this post Link to post Share on other sites
piisfish 140 #2 March 30, 2011 QuoteAre the Argus and Vigil cutters exactly the same? Does anyone know of any difference in construction or materials used? Anyone care to offer any theories? . -NO -shape and size of the holes are not the same, cable is different, certainly much more differences, but I have never seen a real Argus cutter -I wouldn't offer more theory than : Vigil have had their share of problems with cutters (4-5 versions publicly released ?) before getting to the actual one. I wish for Aviacom and Argus owners that they find a solution quickly with these cutters as they seem to be the major problem. Fire/no fire parameters seem to be OK (can't remember recent cases of people complaining about that)scissors beat paper, paper beat rock, rock beat wingsuit - KarlM Quote Share this post Link to post Share on other sites
theonlyski 8 #3 March 30, 2011 Quote -shape and size of the holes are not the same, cable is different, certainly much more differences, but I have never seen a real Argus cutter I've got one of each right now, will try to post some pics tonight."I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly DPH -7, TDS 578, Muff 5153, SCR 14890 I'm an asshole, and I approve this message Quote Share this post Link to post Share on other sites
pchapman 279 #4 March 30, 2011 Yeah, anyone know where to find info on Nato stock number equipment or EU patents? Vigil states EU Patent N° EP1512626A2, NATO Stock Number (NSN) 1377-13-119-7112. They say they have a circular knife. I've heard someone claim that it is a two blade system though. But there's a possible explanation for that: Note how the main barrel of the cutter is smaller than the barrel around the closing loop hole. So it is possible that this means the Vigil's circular blade ends up away from the tubular wall, and would pressing the loop against an anvil, in effect acting as two blades. This would be rather than cutting in a shearing action, circular blade sliding past the surrounding housing, which is the case for the Argus. I would also like to learn more. Quote Share this post Link to post Share on other sites
dpreguy 14 #5 March 30, 2011 To all, I guess I could just call Eric Campbell at SSK and ask; but...what is the defining difference between the Cypres cutter and Vigil's and Argus's? Or, for that matter, the differences between all of the cutters? (Or are they even different? Maybe just a better quality machined product? Just fishing here) Just searching for knowledge. The Italian" partially cut" photos were sooo scary, especially for those rigs with the cutter above the pilot chute=Most rigs nowadays, except the Sunpaths. Trapping the loop above the pilot chute means nothing gets out, even if you manually pull the ripcord! Quote Share this post Link to post Share on other sites
matthewcline 0 #6 March 30, 2011 QuoteTo all, I guess I could just call Eric Campbell at SSK and ask; but...what is the defining difference between the Cypres cutter and Vigil's and Argus's? Or, for that matter, the differences between all of the cutters? (Or are they even different? Maybe just a better quality machined product? Just fishing here) Just searching for knowledge. The Italian" partially cut" photos were sooo scary, especially for those rigs with the cutter above the pilot chute=Most rigs nowadays, except the Sunpaths. Trapping the loop above the pilot chute means nothing gets out, even if you manually pull the ripcord! Isn't Sunrise's Wings a set up like the Sunpath? MattAn Instructors first concern is student safety. So, start being safe, first!!! Quote Share this post Link to post Share on other sites
pchapman 279 #7 March 30, 2011 A helpful document about cutter design is the following, for circular cutter (using shear) vs. single cutter (against an anvil): http://www.mediafire.com/file/d14p3e5axy5pxpe/ARGUS%20Cutter%20Review%20%28APF%20rigger%27s%20critique%20of%20circular%20Argus%20cutters%29.pdf It's a June 2010 report by an Australian Parachuting Federation rigger about Argus cutters. I can't find where on the web I originally downloaded it, so I uploaded it to the above file sharing site. Quote Share this post Link to post Share on other sites
theonlyski 8 #8 March 30, 2011 Quote Isn't Sunrise's Wings a set up like the Sunpath? Matt The cutter is in the same location, against the backpad in the reserve pack tray."I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly DPH -7, TDS 578, Muff 5153, SCR 14890 I'm an asshole, and I approve this message Quote Share this post Link to post Share on other sites
SethInMI 174 #9 March 30, 2011 I must have missed that pdf the 1st time around, thanks for posting it. The pictures on page 3 are great for showing the cutter differences and the possible/probable failure mode of the Argus cutter. The report author makes the case for the superiority of the cypres cutter design. I am going to print it and bring it to our Safety Day on Sat.It's flare not flair, brakes not breaks, bridle not bridal, "could NOT care less" not "could care less". Quote Share this post Link to post Share on other sites
KellyF 16 #10 March 30, 2011 There is a lot of good information in that document, but the illustration is not accurate in regards to the anvil location relative to the hole the closing loop passes through. The anvil location is the same as in the "V-Blade" cutter illustration, as least based on the two Argus units we have in house, and the technical drawings I've been provided with. Quote Share this post Link to post Share on other sites
SethInMI 174 #11 March 30, 2011 Kelly, That is interesting, you are saying the Argus cutter is NOT a shear cutter. The susceptibility to jamming of a shear cutter on a non-tensioned material is a MAJOR point in the APF report. Anyone know if the Vigil a shear cutter? Did Argus change from shear to anvil? [Edit] After thinking about the geometry of a circular cutter passing by a round hole, there would have to be some shearing action at the hole, even if the anvil surface was moved up to be in line with the bottom of the hole.It's flare not flair, brakes not breaks, bridle not bridal, "could NOT care less" not "could care less". Quote Share this post Link to post Share on other sites
pchapman 279 #12 March 30, 2011 Interesting! So that's saying that the anvil is not set back from the cutter's closing loop hole, but essentially even with the side of the hole. It would be either right at the hole or perhaps set back slightly if there's some inner lining for the cutter hole. Any of that would tend to change the shearing action towards being a straight cut against an anvil. That assumes the loop remains or is pushed towards the center of the hole laterally, where the hole is furthest towards the end of the cutter and thus right up near the anvil. (Round cutter hole vs. flat anvil) So it still depends exactly where the anvil is relative to the hole, and whether there's any issue at all if the loop is displaced to the side. Quote Share this post Link to post Share on other sites
johnmatrix 21 #13 March 30, 2011 Quote So that's saying that the anvil is not set back from the cutter's closing loop hole, but essentially even with the side of the hole. It would be either right at the hole or perhaps set back slightly if there's some inner lining for the cutter hole. In a document attached to a post on p2 of this thread: http://www.dropzone.com/forum/Skydiving_C1/Gear_and_Rigging_F6/Argus_AAD_misfire_P2442321-2 a diagram of this version of the Argus cutter indicates that a floating insert lies on top of the anvil. (I'm not sure exactly what was changed in further revisions of the cutter, did they say it was a stronger blade? Was the insert still included?) Quote Share this post Link to post Share on other sites
popsjumper 2 #14 March 31, 2011 Quoteand whether there's any issue at all if the loop is displaced to the side. That is another point of contention...how the loop passes through the hole. Straight through or at an angle. Straight through - no problem? Angled through - shearing and lock-up? I see this, if it is indeed a problem, as the MAJOR problem...the root cause, if you will. How can any rigger ensure that the closing loop passes straight through the hole after the flaps are closed and how can they ensure that it remains in place throughout its pack cycle...they can't. I can see AAD manufactures shifting blame to the rigger...but NOT legitimately. If it's a problem, then IMHO, it's up to the manufacturer to fix it...NOW.My reality and yours are quite different. I think we're all Bozos on this bus. Falcon5232, SCS8170, SCSA353, POPS9398, DS239 Quote Share this post Link to post Share on other sites
