Parachute Question
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for me I have all Fruity Chutes from 16"-36" the 16"-24" TARC chutes the rest are the standard elliptical chutes. I forgot I also have WM Recon chutes 20" 30" and 40". I have less chutes than most and change them out depending what rocket I'm flying. I also plan on getting some Top Flight "X" chutes for different flying conditions.
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I like PML Dura-chutes. They all have spill holes which minimizes spin on descent. I spend so much time unraveling twisted shroud lines and shock cords it's insane. I also shift chutes between rockets, so they minimize turnaround. They also don't cost an arm and a leg...
Right. This is the reason I'm checking in here. I get a lot of tangles too. Braided lines. I also move chutes from/to different rocket. And I have swivels on them but don't understand how the lines get so messed up. No love for that issue. Any suggestions to help avoid this issue.??
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Interesting. I was just in Walmart looking at material. I think I'm going to make my own. I love a big chute but I fully understand the negatives to that.
Mike's reply suggests spill hole chutes. I have one that's 18". I'm thinking about a Jolly Logic chute release. I'm just not ready for electronics yet.
I got rid of my PML chute because they cross their shroud lines
boatgeek
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Walmart nylon probably isn’t thin mill but that’s OK too. If you already have a sewing machine and rudimentary sewing skills, you’ll be fine making a chute. Smaller ones 12”-18” you might just as well make a flat sheet with shroud lines. Once you get bigger it seems like making gores is easier. Once you go there, it’s easier to build in a spill hole than not since you don’t have to make all the seams join up.
From experience, the Walmart nylon is extremely combustible. I ordered ripstop from Amazon but haven’t used it yet.
Would this work to protect the chutes?
https://www.amazon.com/ForceField-FireGuard-Flame-Retardant-Protection/dp/B003VASNKU
Would this work to protect the chutes?
https://www.amazon.com/ForceField-FireGuard-Flame-Retardant-Protection/dp/B003VASNKU
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LPR hex chutes are stupid easy to make. I haven't sewn since a single project in middle school about 15 yrs ago, but had no problem making an effective parachute (note that I did not say pretty). These are great practice for sewing in general
I think it is a LOT to do with technique. 1) "Z-fold" don't "wrap".
2) orderly in => orderly out
3) consistency so effects of small changes in technique can be observed in how it effects outcome.
(Plus lots of practice.)
We did a duration contest with a Big Bertha on a B motor limit. I made a 60" parachute out of .5mil plastic with (48) 72" fine thread shroud lines....first launch I left it sit too long (overnight) and it didn't open. After fluffing, and repack 2nd flight was cool and NO tangled lines, but packing it takes about 40-60min of tedious work.
The 3rd flight it caught a telephone line and got a little damaged during getting it down. I need to find video I think I have it on my phone of the last flight.
Here is the Big Bertha "laboring" off the pad with the weight of the (payload), then deployment, and my kids playing with it after it took some damage from the phone line recovery...
[Edit: I forgot till looking at the pictures it has a 12" estes chute attached at the 2" spill hole as a pilot to help get it oriented and open quicker. That is what you see in the second image. ]
[Edit: I forgot till looking at the pictures it has a 12" estes chute attached at the 2" spill hole as a pilot to help get it oriented and open quicker. That is what you see in the second image. ]
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Traction.... In all due respect, meaning, I'm by no means coming at you so please bare with me here...... You are telling us that you take 40 to 60 minutes to pack a chute.?? Wow. That is a crazy number right there. But here's the thing..... You packed a chute the night before a contest and it didn't deploy.?? My gosh.!!!! You speak like a beginner and then in a snap you are giving expert advice. LOL ..... That's a big spectrum right there. Couple questions.....
Do you recommend longer shroud lines or shorter lines.?? What I've learned is with a 24" chute the lines should be 24 inches. But, I tend to prefer longer lines for no reasoning at all. And most of the chutes I have come strung up so I don't have a choice.
Also, I find that I pack a plastic chute better than a nylon chute. Nylon is preffered but its very slick. I kinda like a 32" plastic chute but the quality isn't there. I can see it. I can answer my own question...... With nylon I need to be more patient rolling it up. Nylon sort of takes on its own shape. I need to get the lines together before I go any further. I definately like the Z-fold. But still, I have to roll it once or twice to fit it in.
I just read your picture post. THAT looks pretty cool. I'm impressed. Its a big chute to fit in a little tube. The smaller chute is cool too. I love those pictures. I watch a lot of videos and the best ones are the deployment of a chute that unfolds so neatly and slow and just fills with air in almost slow motion. I wonder if I'll ever get to that point.?? Hope so...... It's a pretty sight to see.!! I bet yours was like that. The pictures sort of capture it that way. Impressive.
I like your comment about making subtle changes and taking note of the result. That's just plain being smart. Me.??..... Well...... LOL . I'm the OP here. Thanks for your reply and I'm all ears if you have more suggestions along the way.
Oh, and this too..... I've mentioned it already but, how about ejection. It's violent. Do the lines tangle at that point or is it the big wide circling on the glide down that 'braids' the lines.?? I think my first bit of electronics will be a Jolly Logic chute release. Would this help.?? And I'm also considering a parabolic chute. Just 4 lines. Do those tangle too.?? Lots of questions here and they are not very organized. Laughing. Help.!!!
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No offense taken. I like to experiment, and that chute diffenitely was. That was a huge chute to get into the B-B, and the shroud lines were literally a strand of upholstery thread. With 48 of them getting each section folded over, and lines straight was a task. (I think 40-60 min was a good time.) I knew after sitting all night it could be iffy...I had put lots of talcum powder on it and was hoping for the best.
Depends on type of chute. 1.5 times the diameter is the general idea for flat sheet chutes. Then reef it shorter for faster decent speed based on rocket weight, field size, and wind, etc.
Nylon IS harder to handle when folding and rolling. (I have numbness and have lost some feeling in my hands. That makes it even more so.) Just don't rush.
You will. Just need to figure out what works for you.
BOTH, but mainly during the deployment process. Anything you can do to make that more orderly and less violent will help. Spinning on decent will just twist, not braid, the lines.
Chute release will not do much for less entanglement, and ADDS more complexity. It cuts down on drift. The flopping around before main deployment CAN make tangling worse.
I did just get (2) 4 line Rocketman Parachutes to "play with" this summer. So TBD for me.
Asking how to pack a chute will just get an argument going. Lots of people feel their way is the only way, and will put down all others. That is not useful. General conversation, then take bits-n-pieces, try it and see what you like. It's a refinement process for each of us.
(If you want to see how "I" do things I can take photos and post "my" process. But there are LOTs of that type of thread already in this forum.)
Mike
Super reply. I appreciate that. Thanks a lot.
shockie
High Plains Rocketeer
does anybody make :
1. thin mil chutes with spill holes?
2. printed thin mill chutes......
specifically a 18 to 24" thin mill chute with that Skull and Crossbones on it from the new Estes DRM kit
well here's a business opportunity for you. you're welcome. And if it's made in China, no thanks.
1. thin mil chutes with spill holes?
2. printed thin mill chutes......
specifically a 18 to 24" thin mill chute with that Skull and Crossbones on it from the new Estes DRM kit
well here's a business opportunity for you. you're welcome. And if it's made in China, no thanks.
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I usually go 1:1 shroud to diameter. Next time I will try longer, I always wondered what effect that had on descent but never bothered to ask.
Honestly thought you were kidding with an hour for packing, but that is a huge chute in a comparatively small rocket.
Not sure but I'm curious, what about a thread embroidered pattern on rip stop nylon? Depending on the design the added weight would be minimal. Similar to a patterned kite.
Sluggo, I don't mean to hijack your thead. If you want this removed let me know.
Here is video of full flight.
This is close up of deployment at 3/4 speed. Not clean. (Snagged a fin in a loop of the shock cord). But you can see how quick the pilot "pops", then the main fills.
Here is video of full flight.
This is close up of deployment at 3/4 speed. Not clean. (Snagged a fin in a loop of the shock cord). But you can see how quick the pilot "pops", then the main fills.
shockie
High Plains Rocketeer
it just dawned on me that if one were to use a hot knive blade you could cut and seal a nylon chute if you put a spill hole in it .
https://www.michaels.com/walnut-hollow-professional-hotknife/10389558.html
this should seal the nylon preventing it from fraying and not requiring any threading?
I have ”cut” rip stop with just a normal soldering iron tip. Works great, but one of those knife tips is on my list of things to acquire.
THANK YOU.
One of my plans for this summer is a Super Big Bertha with 3 of these huge chutes packed in deployment bag with 3 compartments. If I catch a thermal over a dirt field, it may go "up" on the chutes...lol
I can't fly these huge chutes on anything other than a dead calm day, to low altitudes, and they still drift a long ways.
BUT people do like to watch every time I do it. Like you said watching it fill with air is neat to watch.
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The X parachutes apparently drift less than regular hex chutes. Is that simply because they drop faster (so equivalent to a smaller chute) or some thing aerodynamic about them?
second question: I actually have some woven Kevlar cloth, any reason why normally nomex is used instead for parachute protection (instead of wadding)
second question: I actually have some woven Kevlar cloth, any reason why normally nomex is used instead for parachute protection (instead of wadding)
The following has been my experience with making a 30" elliptical parachute, from finding fabric, to choosing a machine needle and thread, adjusting tension, etc. YMMV.
The material at my local Walmart is 1.7 oz ripstop, uncalendered. This is too heavy, and because it is not calendered, air passes through the weave, reducing the drag coefficient.
I get my nylon here:
https://ripstopbytheroll.com/collec...ucts/1-1-oz-ripstop-nylon?variant=11187595457
Wide range of colors, 1.1 oz. Be sure and select 'calendered'. And unless you're buying a roll, select 'cut and folded' for shipping. Way cheaper.
Ripstop nylon is difficult to work with because it doesn't stay folded. Hemming an end, for example, you'll fold it over a quarter-inch, press it with your finger, then fold it over another quarter-inch and press it again. Then run a stitch down the center of the fold. Ironing the fold (mind the heat) isn't that much better.
I use a fabric glue pen (like a glue stick but narrow, and water soluble)—glue an edge, fold and press, glue it again, fold and press, then stitch. The glue washes out of the fabric. Just soak the finished parachute in lukewarm water for 10 or 15 minutes, then hang it up to dry.
Glue pen:
https://www.joann.com/fons-and-porter-water-soluble-fabric-glue-marker/8666794.html
FWIW, I have two different presser feet for seams—a rolled-hem presser foot and a felling foot (for the flat felled seams that join the gores)—and neither of them work very well with 1.1 oz. ripstop. They're great for denim, cotton, etc., but not nylon. So I fold and glue, then stitch with the standard foot.
Sewing a flat feeled seam with a standard presser foot:
Next comes the needle and thread. Everyone in the sport-utility fabric-sewing universe says to use a 70/10 needle for sewing ripstop. That's a very thin needle, and works well for ripstop. The problem is that they also say to use a heavy nylon thread (upholstery thread). And while it's possible to thread a 70/10 needle with upholstery thread, it will NOT feed properly. You'll tear your hair out adjusting thread tension, trying to eliminate the inevitable looping bottom stitch, when all along it's not the tension at the top rollers or the bobbin that's causing the problem. It's the thread being too wide for the eyelet in the needle.
If you're going to use heavy nylon thread, use an 80/12 needle or possibly a 90/14. But be prepared for overly large holes in the fabric. If you're going to use a 70/10 needle, use a lighter weight thread.
Also, use a 'universal' needle, not a 'ball point'.
The spill hole (apex vent, according to the purists on these boards) keeps the parachute from oscillating on descent. If you've ever wondered why the rocket circles underneath the parachute, it's because the parachute wants to 'dump' air from beneath the canopy. So it tilts to release pressure, first to one side, then the other. This swinging motion causes everything that's suspended from the parachute to circle. The longer the shroud lines and shock cord are, the wider the circle will be.
Typically, the diameter of the spill hole is 20 percent of the total parachute diameter. This seems like a very large hole in the canopy, but it's just 3 percent of the total area.
Shroud line material is a matter of preference. Some use Kevlar. That's a little stiff for me, and because I'm wrapping the parachute in a Nomex blanket, I don't need the heatproof properties. I'm using this for a 30" parachute:
https://www.amazon.com/gp/product/B07FVN9V4X/
It's braided, pliable, but strong.
The shroud line attachment to the canopy is the most critical part of sewing a parachute. If these pull loose, you're toast. The following product page from Apogee has pictures of a 36" parachute. The fourth picture shows how the shroud line is attached. Note the loop, and the stitch going through the cord, not zigzagged along the sides.
https://www.apogeerockets.com/Build...Larger-than-24in/30in-Printed-Nylon-Parachute
Here are a couple of more sites with info on making a parachute:
Basics of making an elliptical parachute (from Fruity):
https://fruitychutes.com/help_for_parachutes/parachute-help/how_to_make_a_parachute.htm
More detailed info on elliptical chute design (plus excellent diagrams on how the fabric folds for flat felled seams):
https://www.nakka-rocketry.net/paracon.html
FWIW, Nakka uses seam-reinforcing tape on all of his seams. This would be important on a heavy rocket (3+ pounds) with a large diameter chute (maybe 40" and up). My 2.6" inch scratch-built, 40" long, weighs barely a pound. I don't need the extra weight from seam ribbon.
Finally, and quite apart from making a parachute is this:
I have a similar problem with my left hand. If it's numbness (pins-and-needles feeling) in the pinky and ring finger only, it's a condition called 'ulnar compression', in which the nerve that runs past the elbow comes out of the channel that is supposed to keep it in place. The result is a constant feeling of pins and needles in those two fingers, extending down across the palm. In my case, it also leads to cramping of the hand.
There's a sleeve you can wear that restricts movement of the elbow. But it's really hard to glue rocket parts together if you can't bend that elbow. And surgery has mixed results.
I just live with it.
All of the foregoing (both parachute making and hand numbness) is my experience only. YMMV.
Realized I never answered your original question... lots (~20) of Estes chutes on the LPR rockets. 9" thru 18" most with cut spill holes. My scratch builds, and MPR get 9" thru 36" LOC Precision chutes (~15). (Nylon with spill holes.) Then during Rocketman's black friday sale, I picked up a 12" and 60" to play with this summer on (2) HPR's in construction now. (Low and Slow)
My oldest kid ( 8 ) is learning to pack Parachutes, Load motors, etc. So burning up a few Estes chutes is in his learning curve. (Too little protection - burn the chute, too much or packed too tight - doesn't come out body tube, not packed well - tangled lines. ). The 3 year old still gets to "just watch". The 5 year old "helps daddy", sometimes..lol.
My oldest kid ( 8 ) is learning to pack Parachutes, Load motors, etc. So burning up a few Estes chutes is in his learning curve. (Too little protection - burn the chute, too much or packed too tight - doesn't come out body tube, not packed well - tangled lines. ). The 3 year old still gets to "just watch". The 5 year old "helps daddy", sometimes..lol.
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You lost me after this point.
For real though, this part of model rocketry almost feels like a different hobby entirely. I will definitely try some of these things next time I sit down to make a parachute, thanks for some new reading.
That's been my experience, no matter who I'm talking to, beginning with my wife. So you're in good company.
I used to shoot archery at a professional level. Pulling an 80# bow and shooting with "back tension" for almost 20 years; is what I blame my shoulder, elbow, and wrist issues on. I do "just live with it" but I will be seeing a specialist next month. If I don't concentrate on keeping my grip tight, I drop stuff. And that is happening more and more lately.
Back on topic.
I did follow most of your post. I have been pulling my hair out over bottom looping. I will need to check needle. I thought it was big enough. Maybe just buy some bigger eyes and see what happens.... THANKS FOR YOUR INSIGHTS.
@Dane Ronnow , FYI, if you let that ulnar compression go too long, it will progress from cramping, to a permanent “claw” hook on those two outer fingers. Had that issue about ten years ago, constantly numb half hand. Drove me nuts. Ended up having ulnar nerve transposition surgery, and after about a year, no more numbness, and back to full strength. I DO have to be careful now though, as my “funny bone” is now on the inside of my elbow. I can light it up just setting it on an armrest if I’m not careful! 
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