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Quagmirian

My little project

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RiggerLee

You didn't put four links on each riser did you?

Uh... sort of...
I put two extra slinks on each rear riser, single wrapped. So it added about 4 inches to the rears. I'm not doing that again. It was fine for two jumps, but just seem to be screaming out if the sky on the third. Also it fucked up the openings. When I get home I'll give it a good inspection before retrimming it. I've only managed 10 jumps on it and I feel bad because it seems to have a lot of potential.

Onto other things, I did my 201st jump today, so you know what that means...
[inline dive.jpg]
The internet is a bit dodgy here so I'll upload the full video soon. There are some interesting things in it.

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There at about 7:00 where you say, "That's new." It looks like you took it right to the edge of a stall and then let one toggle up. Or took it to the edge and then let up and imedently buried the left toggle. Basically what happened is the right side started to surge forwards and the left started to stall and back slide. If you had continued to hold it or maybe pushed it a bit lower that side of the canopy would have stalled out and started to slide backwards as the other started to fly. The canopy would have rotated over you head in basically a flat spin. You can do this with almost any canopy. Depending on a lot of things, including line length, how stable it is in a stall, AR, how the break lines are spaced, etc. It can be any thing from a fairly stable state to quite a wild oscillating ride. It's a good way to put your self in major line twist. To recover bring the right toggle down and slow the advancing side and then double clutch the left stalled side. Be ready for a big surge as the canopy tries to dive and start flying forward again.

I think things like this are a lot of fun. And as long as you're ready for what's coming, including the possibility of line twist, a spinning canopy barber poled with one control line locked down, and possible even a cutaway, you can have a lot of fun playing with your canopy like this. Just to be clear I'm not discouraging you. In fact at some point you might want to see how it behaves in this state. It's not a normal flight mode but it can happen if you over control the canopy during or just after opening with a rear riser and too deep of a break setting. Or in really deep toggle turns where you have a high G loading. If the guy has really long arms some times he can stall out that side of the canopy and experience a G induced stall. It usually winds up in line twist with him spinning on his back. Thing is it can be hard to test fore. Part of it seems to be how tall the guy is and line length of that size canopy. Some times it can be more violent depending on how the dynamics work out. What I saw there seemed pretty docile. Don't be afraid of this, just be ready.

Not really a sniveler but every thing else that I saw seems really well behaved. Seems to have a little higher angle of attack in the center then at the ends. Based on what the nose looked like. Maybe you could go just a bit wider on the panels at the front of the canopy. I'd tilt the axis that you're rotating it around down just a bit when you create the panels. The lip on the nose is a bit wrinkly. It looks like it's just bent straight over. You know that the unloaded rib is going to want to drift upwards. You might put just a bit of angle in the out side edge of the panel at the lip to allow that to happen. You might think that by keeping it square you're holding it down but what little you get is only at the lip and I think you are just distorting it and pulling down the leading edge of your nose at the unloaded rib.

Looks like a canopy. Flies like a canopy. Seems to land very nicely. I think you should be fucking proud of that thing.

Lee
Lee
[email protected]
www.velocitysportswear.com

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Yeah, that's basically what I did. Full toggles and then let up one side. What's weird is that I'm sure I did it before and it didn't start to spin. Along with toggle sashaying it's a thing I need to dedicate more jumps to. On that note, the nose tends to creep down and then bounce back up a bit when toggle sashaying. I actually managed to get half a line twist doing that. But all the jumps have been with the slider down, so I still need to test worst case scenario.

The openings have actually been pretty good since I changed the brake lines from 1,2,4,6 to 1,2,3,5. 1000 feet from throwing the pilot chute to releasing brakes. And they seem to be quite consistent, so if you open right after a track, you get a nice gentle kick from the snivel and you end up open at the same height.

I'm going to see if I can get at least one of these canopies cleared by a BPA rigger. Wish me luck.

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It's worth playing with it with the slider up as well. I don't think you'll see any real difference with this canopy but with smaller canopies that small increase in anhedral, arc, can make it a bit more twitchy. Some canopies with specter lines when they get out of trim and the tips shrink down can get down right scary. They become become less stable in roll. I'm talking small things, an early 72 fx comes to mind. I think that's part of the reason every one went to Vectran and HMA. I doubt you'll actually be able to tell the difference with this canopy.

Some of this you're getting into piloting rather then design. Let's take the sashay line twist as an example. With some thing like that you can very easily unload the canopy. At that point it can easily turn leaving your body behind. Some of this is a technique thing. you can kind of keep it loaded with how you fly the canopy and the timing in how transition from one toggle to another. I can't really explain it. The closest analogy I can come up with is how you waggle your wings in a plane and how the rudder and yoke are coordinated. You probable wont get that but the point is that that really isn't a design issue with the canopy. In fact it speaks well of the canopy. It implies that it's reasonable efficient and has decent flair authority. In fact I'd be disappointed if you're canopy wasn't capable of that. But this isn't a defect. If any thing it's a result of your rather light wing loading and a fairly high performance canopy with good flair authority. You see this all the time when young jumpers used to buy saber ones at light loadings. If you leave the slider up it will simply be that much easier to do this. That does not reflect on the design.

The nose on sashay. You will unload and reduce the AOA on one side of the canopy during this. To some degree this again relates to how you fly the canopy. It's normal. Now as it relates to my earlier observation. Looking closely at a couple of the pictures where you seemed to be in full flight. At the glide angle of the canopy you seem to have a slightly lower angle of attack towards the tips. In one since that would not be considered a bad thing. You might do that on a plane. But his is a canopy. If you run out of lift on the wing tip it's going to fold. To be clear I don't think it looks scary, but I think it could be better. It's a subtle change but If you revisited the angle of the line about which you rotate the airfoil, I think you could improve that. It's some thing I think you might look at on the next iteration of this canopy. It will just mean two new pattern pieces, top and bottom skin. As it relates to the sashay, Although a lowering of the AOA on one side of the wing is normal with that. This twist in your wing is not helping. It just makes it more susceptible. Again, I haven't seen any thing scary. But when you build the Yellow Thing Mk 2 this is an example of some thing you might tweak.

I think you have a nice canopy. From what I see It looks as good as a lot of the things that have been built and sold. I can tell you for a fact that it's better and less scary then some of the things I have jumped. I see absolutely no reason that you should not be able to get it "Certified", what ever the fuck that means, by a BPA rigger. That will probable involve letting him jump and evaluate it. The only problem I see is that he may want to do an "Extensive" evaluation of the canopy. In other words, once he jumps it, he may like it so much that you may not get the canopy back. Cough, Cough, (Bribe), Cough. But since at that point it will be an approved design... you start building them in mass and start to recoup some money. Time to start to locking in these designs, expanding the range of sizes and put an ad in BPA magazine. The have a magazine right? I'd go big. Full page color. Headline... BRITONS FIRST RECOGNIZED CANOPY MANUFACTURER!!! CHEAP CANOPIES!!! LOWEST PRICES!!! Your fans on the rigging comity will love it.

Lee
Lee
[email protected]
www.velocitysportswear.com

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Ok, I'm tentatively optimistic. My grey canopy has been looked at and cleared for use.

I've come up with a hypothesis for why my canopies feel 'weird'. The rib design features more curvature towards the front. Even the max thickness is in a usual place, I think this is forcing the Cp more forward than usual, so the nose of the canopy is trying to tilt up and back. It would explain the flatter than expected glide, and to a point the 'odd' turns. Looking back at pictures, I think it might help to extend the inboard steering line a bit.

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Remster

Quote

If I can't get it out of a plane it'll be towed behind a car something



Car-towing a ramair canopy is a pretty stupid idea. Don't do that.




Not if you've got the right set up and equipment. It's a stupid idea to do anything without the right set up and equipment.
Most of the things worth doing in the world had been declared impossilbe before they were done.
Louis D Brandeis

Where are we going and why are we in this basket?

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Well more good news I suppose. I'm trying to get my yellow ZP canopy cleared soon and I'm not optimistic as we've rushed it a bit, but I'll keep my hopes up.

I finally got round to jumping with a friend's GPS. He uses it for swooping, but the data it dumps out is amazing. I think I'll get one as soon as possible. You can sync it with video and the software is free too, so I can share the small files here for everyone to look at.

[inline flysight.jpg]

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I've got some lighter weight tape here. I bought it from Bally Ribbon Mills. I'm using it for a cube sat recovery system project, small round. I just wanted some thing really light, lighter then type 3. I asked them what PD used on their diagonals on their ribs, as an example. they went and checked for me. I asked if they had it in 3/8 inch. Sold me some thing called 7129-3/8" NATURAL PRE-SHRUNK NYLON TAPE. 7129 is their weave number at Bally. I don't think it's any kind of universal spec that you could ask for. They probable have it in 1/2 as well. The 3/8 is like 50 lb tinsel. So it's almost the same strength as f-111, or twice that considering the width. But the point is that on the bias you can basically stabilize the fabric. Looks like PD's shit. Didn't ask for a spec on the elongation but it's really soft. I'll bet that it has some stretch in it so that it doesn't load the fabric too badly. It's a little tricky to sew with. I found that I really need a tape foot to help control it but that was only about $157 from Tennessee attachment. Really cuts down on bulk.

Lee
Lee
[email protected]
www.velocitysportswear.com

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RiggerLee

I've got some lighter weight tape here. I bought it from Bally Ribbon Mills.

I was wondering what that tape was. They use a wider version for spanwise tapes and Paragear sells that. Apparently it has a mil spec. The later PD canopies go for the 120 lb or even Type 3 for the V tapes which I always thought was a bit overkill.

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I don't want to post here for the sake of it, but I know there are few people following this thread so I ought to keep them informed. I remember writing somewhere ages ago that I'd emailed PIA for definition of a manufacturer and hadn't got a response. It turns out I need only consult PIA's TS-135:

Quote

k. “Manufacturer” – The person (or business/corporate entity) who controls the design and quality of the article produced including the parts of them, and any processes or services related to them that are procured from an outside source.



Sounds pretty unambiguous to me. As for jumping my other canopies, I haven't made much progress. I probably won't be going abroad this year either which is annoying. I have started on the long road to becoming a BPA rigger, however I'm stumbling at the first hurdle as it's really difficult to find a supervising rigger.

How much is it to ship a canopy from the UK to Texas anyway?

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Stupid web site just ate my post!!!!

I'll try again. Here in the US the cheapest and most economic way to send some thing over seas is often to just mail it. UPS and FED EX will hand carry things over the boarder for you but the prices are high. Strangely the easiest way is often to just throw it in to the US Postal Service. They take it all the way to the boarder and then just hand it over into the countries own postal service. It's a slow boat but it generally finds it's way there. That is speaking from my end. It may be different or more cost effective to go through a service from your end. You'll just have to get quotes. And it's often best to list it as being sent for or returned from repairs. If it's a sale Customs may step in and hold it for ransom. Funny thing is the never seem to ask for ransom. It just disappears and it's up to you to track it down and beg them to let you pay ransom. So don't put it in any special packaging, don't fold it up all neat. Don't put any fancy labels on it. Use an old box that you recycled, stuff it in a bag. Include a hand written note instructing what kind of testing you would like done and include clear instructions for it's return in that note. It's just a personal item not a SALE or any form of COMMERCE.

As to the definition. Is the BPA a member of or associated with PIA? I like their definition. Have you thought about coming over and taking a shake and bake course here. Do the respect a US Riggers certificate or could that time be counted towards a BPA certificate. Ether way I actually think you'll enjoy the process and will learn a lot from it. Don't think of it as a task, some thing your being forced to do. It's an opportunity to learn and develop a greater understanding of some thing you enjoy. I think you'll really get into it.

Lee
Lee
[email protected]
www.velocitysportswear.com

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Quote



Does anybody know what became of that guy or his canopy?



Yep.
Monte has built several different canopies since then and I am pretty sure he now holds a Masters certificate.

He got his start packing mains at Skydive Carolina around 1992 when he was about 12 or 13 years old. He started building kites at first with scraps of fabric that I would bring him along with stuff he got elsewhere.Anytime it was windy, you would see him get the kites out and fly them for hours at a time.
These kites were 7 and 9 cell "mini" canopies BTW...


MEL
Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

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