Introduction: Full Size Airplane From Scrap Plastic, Hot Glue, and Washing Line.
We have a factory that makes those small plastic signs that you see in people's front yard at election time. We have a pyramid sized mountain of leftovers that we wanted something to use it for. What better than to build a full size airplane with leftovers, a hit glue gun, washing line, and some wheelbarrow wheels?
We designed it with 5 napkins and a 12 pack of beer.
Our only rule was that it had to be plastic. We build the entire airplane out of leftover plastic, used PVC plumbing for the controls, plastic washing line for the rigging, and covered it with clear vinyl.
We got a local racing car company to sponsor pay for the engine, and went to fly it at the local airport with me as the guinea pig.
Step 1: Step 1. Design
I'm a pilot so I know basic aeronautical engineering (classy speak for what shape airplanes should be). Using that knowledge we designed the parts on some napkins over a few beers.
The hardest part to envision was the control systems to make it a full 3 axis airplane, with roll, pitch, and yaw, for which we needed aerilons, elevators and a rudder.
I came up with how to do it while I was actually in the shower not thinking about it. I built a full gimball system for the control stick out of 1 inch PVC pipe, using standard fittings from Home Depot to create a universal joint.
The joints that were solid were glued, and the joints that were meant to rotate were not glued.
Step 2: Wings
Once we had figured out the basic idea we just had to design an airfoil for the wings. I searched around on the internet to find a good slow speed airfoil. We scaled it up to 4 feet long (to use up the leftover pieces of plastic) and used the router table to cut out about 50 of them. We slid these onto box spars also made out of leftover plastic and hot glued them in place.
One we have wing shapes we covered the leading edge and training edges in more plastic to strengthen it up.
The airfoil sections had to be leaned over slightly to create dihedral when we stood the whole thing up.
Then we made 4 main attachment spars by laminating multiple sheets of the plastic together. These just plugged into the spars on the wings.
64 Comments
9 years ago on Introduction
Very amazing buildt - i hope you will make it fly straight one day - must be incredible fun to sit in your selfbuildt plane. i wish it will be an inspiration for others to make such diy planes.
9 years ago on Introduction
We purchase it from our sign supplier. As we buy it 1,000 sheets at a time I beleive we pay about $6 a sheet for the 4mm and $22 a sheet for for the 10mm.
9 years ago on Introduction
Where Can you get coroplast?
Amazing Instructible by the way!
9 years ago on Introduction
A lot of discussion about using corrugated construction material for the leading edge.
I'm wondering if it is really necessary. The curvature of the surface instills a certain amount of section modulus for bending as well as torsion without utilizing the "stressed skin panel" (honeycomb).
jmt
9 years ago on Step 2
Bravo sir, that's the kind of spirit missing from so many of these projects.
Job well done.
9 years ago on Introduction
Dear Goinpostalmarcus, Could you please reply with a quick sentence or two about how you curved the Coroplast on the leading edge to get such a nice smooth curve? I am building a wing for an iceboat and finding that this material will not bend nicely without buckling due to compression on top and tension on the inside of the curve.
Thanks.
Reply 9 years ago on Introduction
You can also create a smooth curve by creasing in the flutes with a pizza cutter, and putting the creased-in side on the inside. The nice thing about doing it this way is you get more spring and strength in the part. I have made several kayaks and dinghys using this method.
Reply 9 years ago on Introduction
Excellent idea. Thanks for sharing your Coroplast working secrets!
Reply 9 years ago on Introduction
That's how we did it except we sliced it on the outside. Take a razor knife (or we actually have a special corruplast slicer) and slit the plastic between each of the flutes on one side. Then when you bend it those slices open up and it makes a nice curve. Depending on the radius of the curve they will open up more but on our full size wings it was barely noticable.
Reply 9 years ago on Introduction
Thanks! If I slice it on the outside I will cover it with some white duct tape or similar material to keep the air flow smooth. This sounds like it will work. Hot glue will be difficult to apply to large sheets at one time as it will cool too quickly. What other adhesives will work well on this material?
Reply 9 years ago on Introduction
The slicer we use is called the Plasti-Kut. It's dirt cheap and works great and available from most sign suppliers.
Reply 9 years ago on Introduction
DGW -- Folks have used corrugated plastic for RC planes for years. For smooth curves, slice the plastic skin on one side to eliminate buckling. Cut several parallel flutes (maybe 6 or 7) on the inside surface of the curve. The plastic will then curve nicely (albeit with some loss of strength).
9 years ago on Introduction
Where are you and are you giving that stuff away?I need a bunch for a Halloween project.
Reply 9 years ago on Introduction
If you're near Zephyrhills FL you're welcome to some.
9 years ago on Introduction
Woah, way cool, massive project!
Ive built a tail box out of the stuff for the back of my recumbent bike.
2 problems that i have are:
1. You have to rough up the coro plast to help the hot glue to stick.
2. Ive had probs with hot glue cracking with age, stress, and cold temps.
Next time, I ll just tack the pieces with hot glue, then
use silicone for the major gluing.
Reply 9 years ago on Introduction
Enough hot glue between the surfaces seems to do the trick. It never had the chance to age as it was never meant to last very long. However it, did pop off ina few places, the rudder pedal, going down the runway, for one.
9 years ago on Introduction
+ 1 million for having the balls to attempt to fly this thing!!!!
Reply 9 years ago on Introduction
it should be made into a RC plane with some flyer/poster hanging at the tail to troll people
9 years ago on Step 2
My plan was only to get it a few feet off the ground just to say it flew. Now we're working on a flying go kart frame.
9 years ago on Step 2
THATS INSANE!!!!!!!!!!!!!!!!!
I probably would have tried to fly it too though