Red Bull gives you wings, but can you give Red Bull wings to fly RC?
We have a passion for making strange things fly here at Flite Test. Last week, I challenged myself to make a Red Bull fly. Here's how I did it.
We can't recommend that you try this at home due to the nature of working with sharp metal. Always stay safe when making and exercise caution when handling sharp tools and materials. That being said, we'll still show you how this one went together.
Step 1: Drink Red Bull
- Take a Red Bull from your fridge
- Drink it
- Feel energized for the build ahead
Step 2: Get Electronics Prepared
This aircraft is a simple 3-channel airplane, so you're only going to need the bare essentials of RC components.
- Locate 2x 5g servos and center them with a servo tester.
- Grab a receiver, motor, and ESC and make sure that the motor is spinning the right way when powered by a small 2s battery - I used an 800mAh.
- Modify the firewall at this stage. It will need to be shaped to fit the rounded Red Bull profile. You can grab yourself a pack of FT Swappable Firewalls that can be cut into shape quite easily.
Step 3: Assemble internal frame
A great way to both strengthen the empty Red Bull and allow yourself to mount your electronics inside the plane is to create a tray, or frame, that can be slid in and out of the main body.
- I went about opening the Red Bull by carefully slicing open the can along the bottom. This can be very dangerous as you can easily injure yourself with aluminum containers, so I made sure to take it slowly and use appropriate tools.
- Trace circles onto foam board. These can be used as strengthening bulkheads.
- Glue together a 'floor' for the battery, ESC and Reciever. I also added a verticle rectangle of foam glued above the floor for strength.
- At this point, you can also glue the motor firewall to the empty Red Bull whilst routing the ESC cables through a small opening cut into the front of the cylinder.
Step 4: Cut Tail
At this point, you can cut out your tail surfaces and add a boom to the internal structure.
- Using a dowel or some other lightweight yet sturdy tube, extend the fuselage by first finding a way to secure it to the internal structure. I cut holes and simply glued a carbon tube in place.
- Cut foam horizontal and vertical stabilizers. The dimensions of these should be proportioned to the size of your wings, but my elevator was around 12" wide and the rudder 6" high.
Step 5: Cut Wings
The plane I came up with had extremely simple airfoiled wings. The style isn't all that dissimilar to the FT Simple Scout. The wing includes polyhedral which helps to keep the aircraft stable in flight. You can create this by gluing extra sections to the ends of the wings.
- Simply measure out seperate rectangles of foam board that are around 10x8" long each. This will be folded in half to create a wing.
- Score in the center to divide the 10x8 into 2x attached 5x8" rectangles. This makes the top and bottom sides of the wing.
- Measure 1" back from the centre score line on one side and score another line. This will make your basic airfoil shape.
- Bevel each of the edges of the center score line. This allows the wing to be folded back on itself.
- You can add extra sections to the wings that are angled upwards to create polyhedral.
Step 6: Attach Wings
I did this with dowels, but this is probably not the best idea. You could cut a wing slot all the way through the can, but this would make it difficult for the structure to be slid in and out of the aluminum cylinder. It could also be mounted above the can with help from a few struts much like the FT Pietenpol.
- Drill holes into the Red Bull.
- Insert dowels.
- Drill holes into wing profiles.
- Slide foam wings onto dowels.
Again, you may want to come up with a better solution than this!
Step 7: Hook up Push Rods
This is a simple process of connecting your control rods from the servos to the control surfaces.
- Run rods from the servos to the surfaces.
- Locate control horns.
- Create a 'z' bend to attach rod to horn.
- Glue horn in place on surface.
Step 8: Maiden it!
By this point, you'll have a fairly finished airplane. The only thing left to do is to balance it out, test glide the plane and go fly for the first time. If you're unfamiliar with taking brand new experimental airplanes into the sky, here's an article with some helpful tips for maiden flights.
With a little expo (30 percent or so on the rudder and elevator), I hopped the plane into the air. It flew perfectly adequately right from the start.
After some trimming, the plane flew hands-off. Admittedly, the un-aerodynamic fuselage and draggy wings didn't make the aircraft a superb flyer, but it was a decent one.
If you're to try this, as mentioned, you might want to go about designing the way the wings to fit the fuselage a little differently. Mine ended up experiencing some catastrophic flutter and it fell apart in midair - I'll still call this one as a success though!
Get out there and build something amazing!
Article by James Whomsley
Editor of FliteTest.com
YouTube Channel: www.youtube.com/projectairaviation