Making a Parachute

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By Craig Zicafoose

I will attempt to document the steps and consolidate the information I gathered from here to make a nylon hemi parachute. Don't let your wife's or mother's sewing machine intimidate you...you can do it! Let me preface by saying, I have never attempted to sew anything in my life until a couple days ago. Previously, I cut and pinned fabric while the wife sewed, but I got brave and finally tried it myself. For some of you this is old hat and you maybe have variations on the method I am about to decribe, any input is welcomed. This just works for me.

Practice on a few scraps of fabric first and get to know the machine. It might help if someone is around who actually has some experience with sewing just in case you need some pointers starting out; threading the machine, reversing direction, changing stitch settings, etc. It's not hard, promise. I was sewing my own chutes the first day with the machine. Just take your time starting out, stitch slowly at first and don't let the machine get away from you, you're not working in a sweat shop!

You'll need some ripstop nylon fabric, obviously. It can be purchased in many different mils(thickness), textures, and colors....just like any fabric come to think of it. I usually just buy whatever is on the $1.50 clearance at Joanns or the dollar table at Walmart. A few yards of fabric will make a LOT of LPR chutes, and quite a few MPR chutes. We tend to like bright colors for spotting rockets, but for the cost difference, I'm not picky. This stuff generally runs $7+ dollars per yard at regular price, still not bad considering the price of a ready made chute. Here are some samples of fabric I scored from the discount tables.

First step is deciding the size chute you want and how many gores(panels). I discovered a link in another thread that helps with sizing the gores and printing a gore pattern, it can be found here.

Start with a six or eight gore pattern just starting out. I'm not entirely sure how hemi sizes work, but can tell you that an 8" hemi comes out looking and performing(probably better) more like a 12" hex parasheet. Your gore pattern will be limited to 12" on this program, mostly due to standard paper size, but I was able to stretch the 12" gore pattern to 125% with my printer settings. This took me to about a 14" gore, I'm guessing. I use a 50% sphere so I have enough fabric to make the hems. Don't get carried away with spillhole size. I went with .5 on the smaller chutes and 1 inch on the larger chutes. Those sizes will actually increase by a 1/2 inch or more once you hem the fabric, just keep that in mind when you size your spill hole.

For this demo, I chose to make an 8 gore hemi chute with the upscaled 12" pattern. I think I chose 1.5 for the spillhole size.

Cut out your paper pattern and transfer the outline to the fabric...I used a Sharpie for this. This is a familiar step for most of us who have cut out fin patterns in the past. Use a good pair of fabric scissors to cut out the gores from the fabric, this will limit the amount of fraying and give you a nice clean edge. You should wind up with 8 panels all the same size like this... gore pattern

Next step is to start pinning the gores together. Start by pinning the gores in pairs like this...

Note that the gores are all pinned on the same side and that the colors are stacked the same. This is important when it comes time to assemble all the gores together, this keeps a uniform A B A B A B...pattern, assuming you are using two colors. Same rules apply using three or more colors.

Use a straight stitch to sew the paired gores together. My machine settings look like this...

Sew the pinned side of the paired gores together, about a 1/4 inch from the edge. Start at the top and work your way down. The machine should have a reverse feature which should reverse direction and let you backup. "Lock" the first few forward stitches by reversing direction for a few stitches then allow it to move forward again. This "locking" technique should be used at the beginning and end of EVERY seam to keep the thread from pulling out.

Your paired gores should look like this (BELOW-LEFT) after they have been stitched together.

Join two pairs together following the same technique as before (BELOW-RIGHT).

Join the two completed 4 gore sections together for one last seam, again using the same method as before. Sorry, no picture here, but I think you get the drift. You should wind up with a semicircle and something that is starting to resemble a parachute.

Hem the bottom edges of your semicircle. Fold and pin the edge about a 1/4 inch. I like to fold it over twice on the larger chutes to make a neater, more finished edge, but once will suffice.

Reverse side showing the entire edge pinned up.

You can see I have pinned some ribbon loops to the edge. These are for the shroud lines to attach to. Some folks stitch the shroud lines right into the gore seams, but loops just seemed easier to me. Cut 8 (or however many shroud lines you need) two inch strips. Fold the strips over and pin somewhere near the gore seams. Here is a pic of the ribbon I used, 50 cent for 10 yards at Joanne's Fabric.

Now it's time to stitch the bottom hem. I use a zigzag pattern for the hem. Machine settings look like this (BELOW-RIGHT).

Again, remember to "lock" the thread at the beginning and end. Go slowly and remove the pins as you go. However keep the ribbon loops pinned until you make a pass over them. Remember the reverse feature? Reverse direction over each ribbon loop you come to, adds more stitches over that area and secures the loops better. Then, continue zigzagging to the next loop, reverse zigzag over loop, and so on. Remember to lock your stitch at the very end of the hem. Should look like this when your done (BELOW-LEFT).

Trim the excess ribbon (BELOW-RIGHT).

Pin the top of the chute(spillhole). Again, 1/4 inch, I just use a single fold for the top....

Use the same zigzag stitch as the bottom to hem the spillhole. Sewing the spillhole is the trickiest part because of the tight radius, just take your time and go slow. Removing pins as you go should help.

It's time to join the edges of your semicircle together and actually form the chute. This is your last bit of sewing. Pin and attach the gores just like you did the previous ones. Don't forget to change the stitch setting back to the straight pattern you used before.

Remember, we have been working on the inside of the chute. Once the final stitch has been made, you can turn the outside-in, or inside-in, or the outside-out, however you want to say it. Here is what it should look like now.

All that is left to do is attach the shroud lines. I prefer Kevlar® for the lines, but upolstery thread and curtain cord can be used as well. Each line coming down from the chute to the apex should be about 1.5 times the length of the chute diameter. I hope Micro doesn't mind me using his pic, but here is the shroud line attachment for a six line arrangement. shroud line attachment (6 lines)

Most of us are familiar with the "B" method since this is how the kit chutes usually come, but I just tried the "A" method not long ago, and I like it much better.

Good idea to use an overhand knot to attach all the lines together at the bottom to keep all the lengths even.

I use a bowline knot to attach the shroud line ends to the ribbon loops. This is where your Boy Scout training skills come in handy. You were a Boy Scout weren't you? Bowline knot

Here is the finished chute catchin' wind.

Rolled and ready to go.

Much of this may be elementary to some, but I hope this helps.

GUEST's OPINION:
"" (X.X.)

1. Recovery
   Always make sure to re-pack the parachute prior to launch if it has been stored inside the rocket and use talcum/baby powder to prevent sticking on plastic chutes and for a visual locator on ejection. - M.C.
2. Recovery
   Go to your local "Mega" mart store. In the sporting goods department you will find emergency blankets in the camping supply section. For around $2 you get a 5' x 7' sheet of aluminized mylar-like material that makes great parachutes and streamers. - T.B.
3. Recovery
   Always have extra parachutes in your range box because they always get burned eventually. I make my own chutes' out of plastic garbage bags, kite string, those little stick on white circles (which you can buy at any stationary store) and fishing snap swivels. As often as a chute' gets burned they are far too expensive to be buying all the time. - R.F.
4. Recovery
   Making Mylar parachutes - I use 1/4 mil Mylar for duration chutes, 1/2 mil for heavier rockets. You can also use thin poly drop cloth for chutes. A cheap source of 18x30" half mil is the "party wrap" sold in gift and card stores. You can make one 18"and one 12" chute from each piece. This is what TLP uses for their chutes. Another is the original space blankets that are gold/orange on one side, silver on the other. They come in very large sheets. The all silver plastic stuff doesn't work nearly as well as the Mylar. First I decide on the size. For small PD models that can be anywhere from 12-30" (I can pack a 30" Mylar chute in BT-5 easily!), for ELD I've been known to make 57" monsters! I make my small to medium chutes octagonal, larger chutes like the ELD monsters 16 sided. First, I cut a square the size I want my chute. Then I start folding it in half, on the diagonals, until I have a 22.5 degree wedge (11.25 for the 16 sided chutes). That makes twice as many layers as I want sides. Now using a paper cutter, I cut one straight edge along the edge of the material through all of the layers. Scissors can be carefully used instead. Don't mess up the stack! Unfold and you have a perfect octagon (hexadecimagon?). Try it a couple times with scrap newspaper until you get the hang of it. For duration chutes I tape the shroud lines from corner to corner. Cut four (or 8 for a 16-side chute) shroud lines (I use B weight nylon string) about 2.5 times the diagonal diameter of the chute. I'll gather them all up, fold in half, and attach a snap swivel to the exact center of the bundle. Now untangle and fan out the lines. Using sticky Mylar or the Apogee/Ring yellow tacky tape, tape the lines to the eight (16) corners working around the chute so there are no tangles or crossed lines. For heavy-duty recovery chutes of half mil Mylar, I use "over the top" shroud lines of E weight nylon. Cut these lines about 3.5 times the corner-to-corner diameter of the chute. Again, find the center of the lines. Also, mark the center of the canopy. Now one at a time place each line so the center of the line is at the center of the chute. Tape at the chute corners. Repeat until all lines are taped in place. Now add one more tape piece in the center of the chute, where all the lines cross. For large chutes, I might add another 8 pieces of tape half way between the center and the corners of each line. Now carefully gather all the lines together without twisting, and tie. I usually run them trough a snap swivel and tie. Place a drop of white or yellow glue on the knot. Either way, now crumble the chute, dust the chute in talc, shake off the excess, and it's ready to use. Tip on which cutter to use/not to use: make the cut with the paper cutter. I've found that those rolling cutters also work OK. However, avoid modeling knives, as they can snag and leave rough edges that will tear. "B' and "E" weight nylon string sources: I don't know the scale, but that's what they call the different thread weights. A recent check in a sewing store they seemed to understand the letter designations, so they must be some sort of industry standard, but they didn't have the nylon thread. Years ago you could buy it from CMR. Maybe a really good fishing store that sells rod blanks for the build your own rod folks would have the E weight. The only rolls of B weight I have came from a friend who bought a bunch years ago. I've been using one roll for at least 15 years, and it still looks brand new. - B.K. from RMR