Introduction: Orange and White Apollo-Style Model Rocket Parachutes
This Instructable covers how to make orange and white multi-gore, domed cloth parachutes for mid- to large-sized model rockets.
In 2019, I built a 1/70 scale model of a Saturn V moon rocket. The kit came with parachutes but they were simple flat parachutes with the manufacturer's logo. While functional, they lacked the visual impact of the rocket itself. Given the amount of detail on the model, I wanted to fly it with multi-striped, domed orange and white parachutes similar to what NASA used for the Apollo moon missions. Several manufacturers were offering parachutes like this but at quite steep prices, especially since I wanted four of them (one for the capsule portion and three for the rocket body). Having made nylon kites for years, I knew I could make what I needed for a fraction of the total cost.
Note: my camera white balance recorded the chutes as more red here. They are blaze orange as will be shown in later photos.
1.1 oz calendared ripstop nylon. The total yardage depends on the size and number of the chutes you plan to make. I made 36" parachutes for this project and used between 1/2 and 2/3 of a yard (each) of white and orange fabric per parachute. I found good deals at Ripstop by the Roll.
White and orange thread (Coats, Gutterman, etc.)
Sewing machine with zigzag foot
Poster board (optional, for plotting gore template points)
Thin plywood or masonite board for template
Glass or masonite board big enough to lay your template on for hot cutting
150 feet of 200 lb braided dacron line (kite string, fishing line, etc.) per parachute
Gore pattern generator. I used the one on Richard Nakka's web site (https://www.nakka-rocketry.net/panfig4.html). Download the Excel spreadsheet and you can generate gores for chutes with the desired diameter and gore count.
Step 1: Generating the Template
To make these parachutes, you need a template for the gores (each stripe within the parachute). I used the Excel program on Richard Nakka's site. This program allows you to specify the diameter of your parachute and the number of gores. It then generates both printable templates and a table of X and Y values for the gore shape. I chose 36" as the working diameter and 30 total gores (15 each of orange and white). The inner tips of the gores get pretty narrow and if you add too many gores it is hard to sew all the hems and seams in the center of the chute. If you went with a larger diameter, you could increase the gore count. I built some prototypes in 18" and 24" diameters and used 20 and 24 gores, respectively, in those.
I had difficulty getting my printer to give me the right shape and size template so ended up manually plotting the X and Y coordinates on a piece of posterboard. I wanted a vent in the top of the parachute that was about 20% of the final canopy diameter so chopped off 3.5 inches from the tip of the gore. The vent allows some air to escape through the top of the canopy and increases the stability of the parachute. I added 1/2" all around for hems and seams. I then traced that pattern onto thin plywood and cut it out to use as my hot cutting template. I sanded the edges lightly to remove any splinters that could snag the fabric.
Step 2: Cutting the Gores
To cut the gores, I used a soldering iron with a filed down tip to make a hot knife. This both cuts the fabric and seals the edges so it does not fray while you're working with it. All raw edges are eventually hidden in seams but the lack of fraying while working is a bonus. Let the tip get nice and hot before cutting so you get a clean, smooth edge as you work.
Lay down a heat-proof cutting surface. You can use window glass or, if you don't leave the iron in one spot too long, fine plywood or masonite board.
Smooth your nylon over the cutting surface and lay the template on the fabric parallel to the fabric grain. Trace the edge of the template with the hot iron to cut out the gore. For this project, I made 15 each white and orange gores.
Step 3: Assembling the Gores
In this project, I matched the thread color to the fabric which meant I had to switch colors for the top and bottom threads frequently. You could also simply pick a color (white is pretty standard) for all stitching to save that step.
Before assembling the parachutes, I hemmed the narrow end of each gore with a simple 1/4" rolled hem. Fold the end of the fabric over 1/4" and then fold it over again 1/4" to hide the raw edge. Stitch the hem on your machine. You don't need a lock stitch on this seam since it will be bound up in the inter-gore seams later on.
Next, take two gores, one white and one orange, and lay them on top of each other so that the clean sides (outside of the canopy) are facing each other and the rolled hems are facing out. Starting at the narrow end, lock stitch and then sew down one side of the gores with a 1/2" hem. You do not need to lock stitch the wide end as it will be bound in the final perimeter hem. Repeat for the remaining gore pairs, taking care to always keep the same color on top as you stitch the pairs together.
Take a pair of the gores and open it out with the seam side down. Lay another pair of the gores on top of it with the seam side up. As before, start at the narrow end, lock stitch and sew one side with a 1/2" seam. Repeat for the other pairs of gores. If you have 30 gores, you'll have an odd pair left. That's ok. Continue to stitch the gore segments into larger and larger panels, laying one panel with seams down and one with seams up. You should end up with a long arc of alternating gores with all the seams on one side. To finish the canopy, take the two free ends, lay them together, and finish the final seam. At this point, your canopy will be wrong side (seams) out.
Because of the curved sides to each gore, the parachute will naturally take on a curved profile. It will not lay flat (so don't freak and think you messed up the seams somewhere!).
Step 4: Finishing the Canopy Seams
With the canopy gores joined, you need to finish the gore seams with a flat fell seam. Starting at the perimeter of the canopy (wide ends of the gores), fold the excess seam material in half and lay it flat against the canopy. This will hide the raw edges. Stitch the edge of the folded seam to secure it. You don't need to lock stitch the start of the seam but need to finish the end of the seam (at the center of the chute) with a lock stitch.
The white fabric I had was not fully opaque so I elected to fold my gore seams in alternating directions so that they all folded over onto the orange gores. This gave me a very uniform stripe width between the white and orange gores as seen from the outside of the canopy.
Once all the gore seams have been finished, the final step is a 1/4" rolled seam all the way around the perimeter of the canopy. Your canopy is now complete except for the shroud lines.
To add the shroud lines, you need one length of line for every two gores on the chute. Each line should be three times as long as the diameter of your parachute (3 x 36" in this case) plus about 8-10% of the canopy diameter (3" in this project) on each end to sew onto the chute itself. For a 36" x 30 gore canopy, I needed 15 lines of 114" each. I used 200 lb braided dacron fishing line. If you can't get the dacron easily, I've also used braided nylon surveyor's line from the hardware store. However, surveyor's line is thicker than the dacron and when you have high numbers of gores, the extra lines become very bulky.
I made a simple 3" long template from an index card to help me quickly measure the length up the gore seams to attach the shroud lines. The shrouds are sewn through the gore seams for strength.
For the first shroud line, take the end of one piece of line, lay it over the seam, and stitch it down with several passes of very narrow zigzag seams, locking each end of the seam. The needle needs to pass through the shroud line with the zigzag, not just go on either side of it or the line will pull out from under the stitching. Take the other end of the line and sew it to an adjacent gore seam. This will make a long, skinny U-shaped line attached to the canopy.
The ends of your second shroud line will be sewn to the canopy gore seams immediately left and right of the first pair. The third line is one gore left and right of the second line, and so on. Your final line should end up with the ends sewn to the seams on either side of the last gore. This pattern is called a "purse handle" pattern and allows you to gather up all the shroud lines without tangling or crossing them. The black and yellow chute pictured here is a small 8-gore chute that shows the general pattern. The only difference in a larger chute is how many gores and line you have.
And there you have it, a completed parachute. It took me the better part of a day to cut and sew each of the four parachutes I made for my Saturn V. Obviously, fewer gores will greatly reduce total time!
Step 6: Finished Chute
Now that the shrouds are all attached, gather them up and draw them all to the same length from the canopy edge to the gathered apex of the line bundle. I like to tie a simple overhand knot in the end of the line bundle to keep the lines from shifting. You want all the shrouds to the be the same length so that your canopy inflates evenly all the way around.
You can attach the parachute to your rocket with a heavy swivel if you like. I just tied the riser from the rocket components directly to the loop at the end of the parachute shrouds for this project.
For this rocket, I put one chute on the capsule and three chutes on the main body. I flew the rocket on July 4th, 2020, to an altitude of around 500'. At apogee, the ejection charge pushed off the capsule and deployed the parachutes. I had a small keychain camera attached to the rocket body and aimed upward. The last shot (ignore the default date stamp...) shows the three body parachutes fully deployed and also the capsule and its chute higher above.
I hope you enjoyed this project and are inspired to create your own fancy parachutes. This method can be scaled down to tiny chutes if you like (I've guided high school students through building 8-gore x 9" chutes) up to 10 feet and larger. These chutes can be used not only for rockets but for other applications like model airplane recovery, instrument packages from high-altitude balloons, etc. And while I chose orange and white here, the colors are limited only by your imagination, fabric availability, and numbers of gores. Some manufacturers will even segment individual gores into different colors for a truly spectacular rainbow effect.
Participated in the
Colors of the Rainbow Contest