Parachute Thoughts

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AfterBurners

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Lately I find myself wanting to rid myself of all my flat / para-sheet style chutes and upgrade to something better like a "Hemispherical" type chute from Spherachutes, Fruity Chutes and CATO chutes for all my projects. Why? IDK maybe I feel more comfortable with the performance of that type of chute. I know the para-sheet type of chutes have been flown with great success from many flyers here and I agree for the money you can't go wrong, but I guess maybe it just boils down to personal preference. I'm also not one to "collect" a bunch of chutes, although I feel having an assorted chutes to choose from helps when faced with different flying conditions.

Another thing I could never understand is the way the shroud lines on a flat para-sheet chute are sewn. If you lay a chute out you see that the shroud lines are sewn from "corner to corner" always causing that one line to cross or tangle with the others, whereas if they were sewn "across" or "opposite" from each other when you grab the chute from the apex the shrouds will be uniform and even and not cross each other? IDK maybe it's my OCD kicking it, but I hate untangling lines. It's funny if you look at an ESTES plastic chute they got it right. Maybe that's why I like the style of the "Hemispherical" type chutes. They seem more uniform and realistic in their design and also provide a greater CD. I mostly fry mid and high power, but even on my smaller rockets I'm still leaning toward the smaller "hemi" type chutes.

Anyway what's your preference and why? BTW - Yes I will be having some chutes up for sale shortly.:)
 
Tough to beat the efficiency of a toroidal. That's what serves as primary recovery on most of my L2 & L3 birds...

Next up would be the ellipticals...


Later!

--Coop
 
I've made every type of parachute for the past 15 years. I started with flat sheets, multi-gore hemispherical, multi-gore ellipical, cross parachutes, triangle parachutes, rotofoils, toroidal parachutes - everything.

For simple rockets (3FNC, single deploy, <3000') I typically go with a flat sheet because the rockets weigh less than a 5 pounds. No use putting all the effort into something that can be done with a flt sheet.

For my altitude rockets I will use 0.9oz calendared ripstop in a Gen2 toroidal parachute. They have about 20% less fabric than a traditional toroidal but have the same drag. The downside is they are time consuming to make.

Just like not all rockets have one size fits all components, the same with parachutes.

As for sewing parachutes, going across from one another is good, but if you flip the parachute inside itself and twist it up a few times, it can be a bear to untangle. With shroud lines adjacent to each other, you know how they go and can work toward something. With across you never know which one was 'first' and how they lay.

I typically do them next to each other and when I tension the lines for the quick link I cover the short section that is wonky with some tubular nylon/heat shrink tubing.

I also sew each set of shroud lines with different patterned cord, so when you go to untangle you can identify them easily.

Edward
 
If you guys who fly the flat sheet chutes just put a swivel or quick link on them this helps them not to tangle. I guess I don't understand why someone would pay more for the chute than the rocket is worth when the less priced chutes work fine.
 
Don't forget that efficiency costs money, if it's buy one perfect toroidal for calm winds, or three different flat sheet chutes to fly in any wind, well, it ain't all about looks when your $$$ floats a mile away and is lot.

All the parachute forms have their uses, and switching chutes to be able to play the winds is part of the skill set of 'flying the field'.
 
Sometimes it's also a matter of getting the most chute in the smallest space. One of my rockets has an 84 inch Ultra Iris in the nose cone, for a 30 lb. rocket. Other chutes would be larger in diameter, much bulkier, and would not work, regardless of a lower cost.

There is no one single best - the recovery system should be engineered to meet the needs and constraints of the project, which may include space (volume), weight, performance, cost, etc.
 
Very interesting responses and it seems every type of chute has it's propose depending on the rocket / vehicle being used and wind conditions. I completely agree with Crossfire about price and spending more on a chute than what a rocket is worth and yes you are absolutely right on both counts including using a swivel. For me I did happen to lose a nice TARC Fruity chute, along with a nose cone and Nomex blanket. Yeah it drifted away when my shock cord burned because stupid me thought I would use a combination of elastic and Kevlar. Guess it cost me, but on the other hand if I hadn't I'm pretty positive I would have retrieved it.

As far as how much to spend, I guess that would depend on how deep your pockets are? Off the top I can easily name no less than half dozen excellent chute manufacturers out there that make some very nice chutes. For me I don't have a chute for every rocket so I'll switch one chute between several rockets and according to flying conditions. So I might invest in a few "Hemispherical" type chutes (18" to 24") for some of my MPR because at those sizes they are a little pricy, but not as pricey at the larger sizes. On top of that they provide a higher CD and can pack into a small space and with the higher CD you can fly a smaller chute on a rocket that would normally fair well with a larger flat sheet type chute. On the larger sizes I might invest in different sized military flare chutes between 36" and 60" they are lightweight and pack nicely and reasonably affordable and again provide a higher CD. I also want to mention a couple 20" and 30" WM Recon chutes for the slightly heavy vehicles. I used a 20" Recon chute in a G-FORCE and it brought it down nicely. Maybe a little quick, but no damage and that was at Lucerne Dry Lake bed. And for windy conditions I turn to Topflight for their outstanding "X" form chutes and assorted colors. Again the "X" form are easy to pack, work great and easy to spot in the sky.

This is just my thoughts and how I think. I don't have a lot of money to spend on chutes so I try to find that sweet balance between cost and performance. For me I guess what t really boils down to and maybe for all of us; it's just wanting to get out rocket back in one piece, because after spending all the time that we do we would hate to see anything happen to our work.
 
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If you add a 15-20% by area spillhole to a flat parachute you can stop a lot of the tangling and rotation issues as well. I don't sew gores on parachutes until they are over 60". Under that a flat sheet works well enough and is easy to pack into those size rockets.

Edward
 
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