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Here’s a quadcopter that I designed and built in response to a CrashCast challenge to build a flyable quadcopter as cheap and as sturdy as possible.

From a construction standpoint multicopters are interesting because (unlike helicopters) they have no moving parts and (unlike airplanes) do not depend on an aerodynamic body to fly.  As a result, we see multicopters made from a wide variety of materials and construction techniques.

I had seen photos of a pool noodle unit previously and wanted to try one for myself for a couple of reasons:

  • Pool noodles are cheap.
  • It would be a good training unit when friends wanted to try flying.  I can’t imagine much you can to do break a pool noodle!
  • It would be highly visible.  My main quadcopter has really thin arms and is hard to see at a distance.
  • It would be easy to light up for night and evening flying.
  • I wanted to see how simply a working frame could be built.  For example, the motors are simply taped to the frame.
  • Let’s face it, it’s just funny to think of flying pool noodles!

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In keeping with the spirit of a pool noodle quadcopter, I wanted the construction to be as simple as possible (for example, the motors are taped onto the arms).  I bodged it together in an evening with materials that were at hand. While originally done as an experiment in minimal design and construction, I was happy enough with the results that I fly it regularly and use it as a trainer when somebody wants to try flying.

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If you build something like this, I encourage you to keep to the original spirit of the thing: improvise, have fun, and don’t be afraid to try out new ideas!

This video shows autonomous flight — I took the video myself while hands off on the radio.

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Project Steps

Cut the arms to length

Cut 4 pieces to 15.5 inches, and one piece to 5.5 inches. The four pieces will be the front and back (yellow in the picture), green (left and side arms. The small piece will be the battery mount.

Trim the side arms

The side arms will be glued to the front arms, so we need the ends of these pieces to be curved. It will be easiest to do this with a jig. Get a piece of thin scrap plywood and cut a two inch circle, using either a hole saw or coping saw. Cut across this hole so you have a semicircle at the edge of the wood.

Take each of the side arms and the battery mount, and cut a semicircle out of the end of each piece. Be sure the ends of each piece are lined up. You should be able to dry fit the frame together with no gaps. I had to cut a couple of scrap pieces in order to get the feel for cutting the curve just right. You can compensate for small gaps while gluing, but if the gaps are too big try recutting the piece.

Reinforce the arms

Make a 1/4 inch slit along the top of each of the four arms. Be careful not to cut through to the center. Insert the 12 inch carbon fiber rods into the slits on the left and right arms, and the 15 inch carbon fiber rods into the slits on the front and back arms. I originally wanted to try 3/16 inch fiberglass kite rods, but I couldn’t find a place to get them conveniently. Some pieces of split bamboo would probably work as well.

Squeeze glue into the slits so that there are no dry areas in the slit or around the rod. This is important, as gaps in the slit will allow the arms to flex. Allow the glue to dry.

I used Beacon Foam-Tac glue, and it worked really well. The only requirement for the glue is that it not melt the foam. Try gluing some scraps together if you’re not sure.

Attach the arms

Make marks on the front and back arms, five inches from each side. Glue the left and right arms to the front and back arms, centering the left and right arms on the marks you made on the front arms. Be sure you’ve got glue over the entire curved mating surfaces. Try to eliminate all gaps, but if you’ve got some small gaps it will be fine. Check your alignment, and secure with blue tape while the glue dries.

Do the same with the battery mount. It fits centered between the left and right arms.

The frame is complete after all the glue has dried. Check your joints, and make sure they’re tight and strong. The frame should be relatively rigid (by pool noodle standards, at least).

Run a length of strapping tape along the bottoms of the main arms. Make sure it’s tight and smooth. This,s in conjunction with the rods in the top of the arms will eliminate flex.

Mount the motors

Cut four plywood scraps to a size that allows you to conveniently tape your motors to the arm. With my roll of tape, a dimension of 1 inch by 3.5 inches worked well. I originally tried zip ties, but they cut into the arm and didn’t keep the motors level. Strapping tape works perfectly.

Tape the four motors to each end of the front and back arms. Use strapping tape on each side of the motor. Run the tape all around the arm so it overlaps with itself. Make sure it’s smooth and that the motors are flat on top of the arms. You can adjust the motor position by wiggling them a bit.

Configure the center mount.

Cut out some of the bottom battery mount. There should be just enough room for a 3S 2200 mAh battery to fit. I bodged the flight control board mount by hot gluing the electronics to a piece of scrap coroplast plastic (just about anything flat will work), and then attaching the coroplast to the top of the battery mount with two velcro straps, one on each side. A third velcro strap holds the battery in place.

Flight Electronics

Configuring the flight electronics is the same as for any other quadcopter. You can follow Chad Kapper’s excellent instructions here. https://makezine.com/projects/make-37/the-handycopter-uav-2/

The Ardupilot Mega is my preferred flight controller board, but I’ve tested the KK2 and Flip controllers and they also worked well.

Note that everything is taped, hot glued, or zip tied to the top of the unit. I did this because I wanted to finish it quickly, and I honestly thought I would recycle the parts after my friends and flying buddies had gotten a good laugh. If I make another frame, I’ll try running some of the wires, etc, either through the arm or embedding them like the rods.

Interestingly, while it’s incredibly ugly viewed from the top, it looks quite nice from the air since you’re mainly viewing the bottom. The farther away it is, the nicer it looks.

I didn’t have a power distribution board handy, so I used Wago connectors to do this. Here are some notes on doing this:

http://eastbay-rc.blogspot.com/2011/03/update-wago-connector-for-power.html

http://eastbay-rc.blogspot.com/2011/03/update-wago-connector-for-power.html

Adding Lights

(picture: lights in air)

Lights were simple to add. LED strip lights fit perfectly into the hollow pool noodles. I used a separate battery for the lights so I wouldn’t have to run an extra wire to the main battery.

I make a big mistake though. I cut a slot in the arms for the LED batteries. They were a perfect fit, but the cut in the arm allows the arms to twist, reducing the rigidity of the frame. I taped a couple of extra carbon fiber rods to the plywood motor mounts in an X shape to counteract this, but if you don’t cut into the arms that won’t be necessary.

At night the yellow arms were quite a lot brighter than the red and green arms. I arranged it so that the yellow arms were powered by a 2S battery and the red and green arms were powered by a 3S battery.

Test Flights and More Information

The Noodle Copter flies quite well. The fat arms catch the wind more than other copters, but it’s stable even in pretty high winds. We maidened it with gust of wind up to about 15 MPH.

http://www.youtube.com/watch?v=hhZ1_tz4l-Y

Here’s a couple of more articles on the Noodle Copter.You can get more information on the Noodle Copter here:

http://eastbay-rc.blogspot.com/2013/07/the-fleet-noodle-copter.html

http://eastbay-rc.blogspot.com/2013/08/behold-noodle-copter.html

http://eastbay-rc.blogspot.com/2013/08/night-ops-success.html

You can follow the progress of the Noodle Copter and other East Bay RC projects here:

http://eastbay-rc.blogspot.com

http://www.youtube.com/user/marhar2?feature=watch

There’s a lot of tutorials on making and flying RC craft of various sort and on using the various electronic bits that make model aircraft fly these days.