Do you want to be the coolest person at every convention? Well, you should consider making these Mechanical Wings! My group and I are currently enrolled in the PTLW course Principles of Engineering taught by Ms. Berbawy where we designed and created decorative/cosplay RC mechanical wings for our side project. This project was inspired by the YouTuber Axceleration who shares videos that showcase her process of creating a multitude of cosplay props. This project was funded by our teacher's nonprofit BerbawyMakers which fosters educational opportunities for many high school students in the Bay Area. Although in this project, my team and I mainly worked with a drill press or with electronics, we were still able to gain a wide variety of skills, which now include sewing!

- Shreya K., Belle G., and Jenny L. <-- check out Jenny's instructable as well!

Supplies

Materials

Sintra Board x 1
12ft of 3/4 in PVC Pipe
3/4 inch 45 degree PVC pipe elbow x 2
4 Inch Linear Actuators x2
Linear Actuator Mounting Brackets x4
8 x AA 12 V Battery Pack x1
zip ties
12 Gauge Aluminum Wire
Loctite Power Grab Glue
Spray Paint
faux feathers
3-inch strap Hinges x 2
Cotton Fabric (~6 ft)
Wireless 12V 4 channel Relay Switch x 1
Fabric Adjuster x4
1-inch Fabric Straps (~4ft)
Fabric Buckle x3
String
Velcro Straps

Tools

Drill/Drill Press
Heat Gun
Angle Grinder
Electric Sander
Jigsaw
PVC pipe cutter
M3x20 wood screws x40 (add more if extra feathers)
M6x35 screws x8
M6 lock nuts x8
M3X15 screws x8
M3 lock nuts x8
Washers x8
Solid core wire
Tapestry Needles
Caulking Gun

Step 1: Constructing the Backplate

In the first part of the project, we constructed a backplate that could support the weight of the wing's frame and fabric.

We used a jigsaw in order to shape the 12" x 24" x 1/4" Sintra Board, and then softened the edges of the backplate with an electric sander. The final dimensions of your backplate will vary depending on the user's back size.
After we cut the Sintra Board to our desired shape, we boiled it in water to mold the board so that it could fit our backs. An alternative to this process is to either bake the Sintra Board in an oven at 150F or use a heat gun, but remember that every process will release a lot of toxic fumes, so be careful!
We then cut holes in the backplate to imitate a backpack and added fabric straps that would secure the backplate to our shoulders. We then followed this YouTube tutorial by Sew Quaint to attach the fabric adjusters to the strap, so that the backplate could fit people of different sizes.
We then cut two more holes in the backplate and sewed on buckles to secure it to our waist.

Step 2: Shaping PVC Pipe

Now that we have our backplate shaped, we moved on to the PVC pipes in order to make the frame for the wings.

First, we had to cut two different lengths of PVC pipe for each side of the frame. We used a PVC pipe cutter to cut our larger PVC pipe into two 2.5 feet pieces and two 3.5 feet pieces.
After we cut the pipes, we used a heat gun to bend them at marked intervals (varying by around 4-5 inches) so that we could form the shape of the frame. For this, we marked spots where the heat would be applied, and once the area was hot enough, we bent the pipe using our hands (with gloves on) to our desired shape. After we bent the pipe, we used a damp towel to cool it off and keep the pipe in its bent position.
Next, we connected the two PVC pipes. In order to do so, we used the 45-degree PVC pipe connector to connect each of the 2.5 feet pipes to the 3.5 feet pipes. We also added a 5-inch PVC pipe to the end to add extra length, but this step was not necessary because you could easily bend the original PVC pipe itself.

Step 3: Creating the Frame

After we shaped the PVC pipe, we started to create the frame of our wings with our linear actuators, mounting brackets, and strap hinges.

We first decided to attach the strap hinges to connect the 2.5 ft long PVC pipe to the 3.5 ft long PVC pipe. We drilled holes into the PVC pipes and the strap hinges and then used M3x20 wood screws to secure them together.
Then, we drilled another hole into the four mounting brackets, so that we could securely mount the linear actuators. First, we aligned the actuators with the mounting brackets, then marked holes on the PVC pipe for the mounting brackets. We used the same M3x20 wood screws to secure the mounting brackets to the PVC pipe. We also used M6x35 screws and M6 lock nuts to attach the linear actuators to the mounting bracket.
Next, we drilled four holes into the PVC pipe and backplate and attached them together with M3x15 screws, M3 nuts, and large washers. We made sure to leave enough space between the PVC pipes so that we could mount the battery pack. Then, we used an angle grinder to cut the protruding screws and softened them with the Dremel's sanding attachment.

Now, we are finally finished with the frame for the mechanical wings!

Step 4: Making the Feathers

In this step, we will make the actual fabric feathers for the mechanical wings! For our design, we made 28 feathers in total, but you can either increase or decrease the number of feathers depending on the length of your frame.

We first used fabric scissors to cut five-inch-wide segments from our cotton fabric.
We then ironed the fabric to make sure there are no creases.
After we ironed the fabric, we glued two five-inch-wide fabric pieces together. To accomplish this, we squeezed Loctite Power Grab glue with a caulking gun and spread the glue over the fabric with a paint scraper. Before we placed another sheet of fabric, we cut a long piece of 12 Gauge Aluminum wire and placed it on the glue between the two sheets of fabric. Make sure that when you cut the aluminum wire, you line it with the ends of the fabric with at least 3.5 inches of excess wire that sticks out. Then leave the feathers to dry for around 24 hours.
Next, we used fabric scissors to trim the wings into the shape we desired, and then spray painted them with purple spray paint.

Step 5: Attaching the Feathers

Now, we use the excess gauge wire from the previous step to attach the wings to the frame. Before you begin the process, lay the feathers on the frame to decide what pattern you wish to use. My group marked every point where the gauge wire touched the PVC pipes so we knew exactly how the feathers were spaced along the frame, and it would make the process of attaching the feathers easier.

Our first step was to drill holes in every marked spot along the frame. We then used washers and the same wood screws from before and wrapped the gauge wire around the screw. Afterward, we sandwiched the wire with two washers and used a screwdriver to secure the screw into the frame.
The feathers on the frame were attached, but not properly secured to each other. We decided to use thick string and a tapestry needle to sew all the feathers together so that they would move uniformly. In the third picture, we have attached a diagram of the sewing pattern we used. We used an in-and-out weaving pattern when sewing so the needle would go through one feather and out the next feather.
After we sewed the feathers, we used a large piece of white fabric to cover the linear actuators and gauge wire to the frame. We attached the fabric with zip ties by poking through holes and fastening it to the PVC pipe. We then trimmed the fabric into curved shapes to improve its visual appeal.
We then attached the smaller feathers to the wings. First, we spray-painted the feathers in an ombre (fading from white to purple) pattern, then spray-painted some of the feathers in solid purple. After we finished this process, we hot glued the painted feathers to the wings. We filled the top three layers with fully white feathers, then attached a few layers of ombre feathers, and ended with solid purple feathers.

Step 6: Wiring/Attaching the Electronics

In our design, we wanted the linear actuators to be remotely controlled so that we could incorporate the illusion where the wings are moving on their own. We decided to use a 12 V four-relay wireless switch module to create this effect. I followed the wiring diagram in the first picture and connected all the positive and negative leads, the linear actuators, and a 12 V battery supply to the corresponding pins on the relay module. After all the components were wired together, we had to figure out a method to discretely attach the electronics to the frame.

In order to attach the components to the frame, we cut adhesive velcro straps and lined them between the PVC pipes on our backplate. We also spaced the velcro straps on the relay switch module and battery pack to correspond with the velcro we had already attached to the backplate.
Once everything was attached to the backplate, we rewired all the components to the module's pins and covered the backplate with more fabric.

The entire frame and electronics are finally completed, and the wings are fully functional! On the remote, the A, B, C, and D keys correspond to the functions on the linear actuators which can either expand or contract, depending on how it was programmed.