Experimenting with Linesets

[packing_jarrett 0]

THIS FORUM HAS BEEN DEAD

So I've been hearing about experimenting with linesets and modding out your canopy.

What have you done to your canopy to make it "better"?

I've noticed how Katana's and Stiletto's look very similar. Their Aspect ratios and spans relative to each other are very similar. Has anyone ever tried to put a katana line set on a stiletto.

I know of lots of times where people have put xaos lines on VX's. What other combo's can you use?

Na' Cho' Cheese

[ianmdrennan 2]

There are some people I know out there trying a few things. I'd offer jumpers caution when experimenting with something that may be volatile.

There are people out there who are paid to do this stuff for us

Low altitude canopy collapses suck.

Blues,
Ian

Performance Designs Factory Team

[SkymonkeyONE 3]

In 1999 and early 2000 it was actually fairly common for people to tinker with linesets for swooping. People were changing trim with longer/shorter rapide links front and rear and people were even lengthening the outer lines to make the canopy "flatter". I know at least three guys that were doing it in Venezuela back then. That's regular Joes, not any factory R and D machines. Jim Slaton used to jump an Alpha with sideways lines and three risers. He said it flew much better than stock, but opened very hard.

Like Ian says, "there are people who get paid to do such things."

Chuck

[Kolla 0]

Hi Jarrett,

I took your question to our chief canopy designer, below is his reply. It took me a few days to get it, since our R&D crew has been out of town most of the week for yet another testing mission :)

____________________________________

As the designer of both canopies, let me state emphatically that the Stiletto and the Katana are vastly different animals. Inspite of what some believe to be true, the planform of the two canopies are quite different, along with many other design aspects. Laying two canopies on top of one another is not a good way to compare planforms, as big differences in performance come from planform changes that are too small to be seen that way. In the early Katana developmental prototypes we used the Stiletto planform, but it soon became obvious that we were not going to get the characteristics that we wanted for the Katana until the planform was changed, along with many other things as well. We went through many many planforms seeking the right feel, before diving into literally hundreds of other subtle and not-so-subtle design changes until we were satisfied.

The performance differences are a result of far more than a different lineset. The Katana line set even has two more D lines, and is not suitable for the Stiletto. The Stiletto was completed in 1992, and was designed for a flat glide, quick recovery arc, and snappy toggle turns, all of which were items that many people wanted back then. The Katana is designed for what many (but not all) people are asking for now: a steeper/faster glide at full glide, a long recovery arc, low front riser pressure, more solid feel on the rears, long swoops and good carves, and a host of other more subtle items that I need not get into here.

Bottom line is that they are totally different! The line set has to work together with the specific canopy design. Combining bits of one canopy with another rarely improves anything, often results in painful lessons, and sometimes in deadly ones. While the line set is one influence on the differences between these two canopies, it is only one, and you are playing with fire messing with it. At best you will have a truck that is a little better in some aspects but a real dog in others. At worst, you will have a seemingly normal canopy that becomes totally unstable without warning. Believe me, I've been there many times.

We are often asked to modify the lines of canopies we didn't design. We won't do it, because we will not get into second guessing the designer of that particular canopy. I know all about the ones we've designed, but I don't feel I know enough about the subtle aspects of wings from other designers to take liberties with modifying them. They should know all about the issues and effects of trim changes specific to their canopy, what works and what gets ugly, because they probably went through a process similar to ours when designing their canopy. They settled on lines that they felt worked the best, so why mess with it?

John LeBlanc
Performance Designs, Inc.
Vice President
____________________________________

Hope that helps explain,
Blue ones,
Kolla Kolbeinsdottir.

Blue Skies Magazine

[packing_jarrett 0]

Nice Article
Yeah I wasn't actually planning on testing it out or anything. Just trying to open up a discussion. Just from a 5 minute research I noticed that between the stiletto and katana they have similar aspect ratios and similar spans. It would be stupid of me to argue with a PD engineer.

Na' Cho' Cheese

[phoenixlpr 0]

Nice.

The wierdest thing I have heard that some CRW dogs have chopped 50cm from their line set. They claimed that flies better that way. Or they might have gained 1,50m on their competitors in a 4 way rotation.

[ianmdrennan 2]

Thanks for taking the time to post that Kolla.

Blues,
Ian

Performance Designs Factory Team

[dharma1976 0]

Ahhh kolla...

you were one of the first factory reps that I met in the weeee first year of jumping

you spent time talking to me about different stuff alongside Chris Martin next to a firey barrel in AZ

I see you continue to be awesome as all get up in that dept...

Cheers

Dave

http://www.skyjunky.com

CSpenceFLY - I can't believe the number of people willing to bet their life on someone else doing the right thing.

[jerry81 10]

A few months ago I replaced the lines on my Demon with a 'competition' lineset (from the manufacturer. I had also been toying with the idea of making a new lineset myself and doing a few adjustments to it (I had the original trim chart), but buying from the manufacturer was cheaper, faster and safer.

The performance of the canopy changed a lot, most noticeably the recovery arc (longer) and bottom-end flare. I measured the new lines when I was installing them and I can tell you the changes were much more than just lengthening the rear or the outward line groups...much more, basically, than what I would have come up with without studying canopy design extensively.

[Supergeil 0]

Now we are talking linesets....

I heard that if you lengthening the upper steering line you will get a longer opening.
But how much and how much longer openings a lets say katana or sabre2 ?

[Spizzzarko 0]

Changing the cat eye location on your brake settings can change opening characteristics. A parachute that opens more in full flight will generally open slower. Please be carefull and make small adjustments as the manufacturer is not stupid and they make their trims for a reason. If you are doing this for gains in competition I do not think that you will find any majic trim setting that will make you swoop 100' further. Spend your time and money on practice or coaching.

[Supergeil 0]

Nothing I will play with just curious