8 Ft Wingspan Coroplast RC Piper Cub Flown by 25cc Weed Trimmer

Picture of 8 Ft Wingspan Coroplast RC Piper Cub Flown by 25cc Weed Trimmer
I love Radio controlled airplanes and have built several kinds from balsa to this large scale plastic one.

This one is made from $25.00 worth of plastic I bought locally at a sign company.
The plastic is Coroplast or corrugated plastic, its cheap and builds fast.

You could also use old election signs, you just need to paint them or make a patchwork airplane.

Total cost with radio and motor was around 350 bucks.

This is an extensive build and can be scaled down for a smaller plane if you wish.
A working knowledge of RC airplanes is recommended to build one of these.

Its also a tough model, it can take several crashes without too much problem.

I have built a couple of the Aircore brand fold and glue airplanes and used them to learn how to fly, I strongly recommend starting out with one if you want to get into glow engine airplanes.

Balanced properly its a predictable airframe. Due to the simplified flat wing it will tip stall with you at low speeds, so learn how it stalls at high altitude before slowing down for your landing. The ailerons are large enough for a decent roll rate.

As with all gas powered airplanes please be careful wile starting it and have fun flying.

Zachary M.

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Step 1: Specifications:

Picture of Specifications:
Semi Scale J4 Super Cub

8 Foot wingspan 16" chord wing with landing flaps
4.6 Foot fuselage without motor, I moved the motor forward to balance the airplane. So max length can be 5.75 feet

25cc motor with 9.5 pounds of thrust.

Total weight with fuel is 15.75 pounds.

Max speed around 45MPH

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Tweakster2 days ago

Goof Muhammad dont talk to Zac like that the guy did us a favor not our fault your mentally challenged and did not understand his plans, other is you sound foreign go back to your country, goofball take a walk clown we were having a good time till you opened your fat lips

Muhammad Ahmed Khan made it!2 months ago

HI Man !

I dont understand wht you have shared with us u didnt mention the fuselage width any where (fool) , I had to modify this plan at several places without those modification it was very poor in strength if u wanna share something with public so plz be honest . I made this cub u can see here !! DLA 32 motor 7 feet span :-)

bmoreau19 months ago
The link to "Wackerengines", is dead. Page doesn't exist.
craftclarity10 months ago

Holy cow, that thing's enormous! Nice build, looks like it must be really fun to fly.

jmensi11 months ago
Where are the PDF plans. I don't see it
ndurrett1 year ago
What was your all up weight
nickademuss (author)  ndurrett1 year ago
16lbs with the 25cc motor
anime_grl2 years ago
hello! would anyone be able to send me links of where i can get some of these items online? pleease??
nickademuss (author)  anime_grl1 year ago
most parts can be had at a local hobby shop or tower hobbies online.
hello, i am about 3 quarters of the way through with the construction of my plane using yours as a guide. i have made some changes. i could not get the coroplast to hold using the glue. i used pop rivets (1/2 inch) with aluminum washers on the other side to hold the wing together. instead of using 2mm coroplast on the top of the wing i used 1mm plastic that i salvaged from an old sign. i also made my own landing gear from an old sign that was 1/8" aluminum. i made it to the measurements from the ordering page in the catalog. i cut it to shape and used a metal break to bend it, it turned out nice. i didn't exactly know how to mount my engine so i drilled two holes in the engine mount (one on each side) and tapered them and using blind nuts i bolted it to the firewall. also you must have had something that turned your carb sideways because i had to make a throttle linkage that bolted to my crankcase to pull the throttle straight back. so i had to mount my throttle servo inside my fusalage and drill a hole through the firewall to connect my pushrod. another thing i did was drill some small holes in the hinge about 2" apart to make the hinges on the tail easier to bend. i am waiting to order my radio so i can get this thing airborn. i have tuned it and fully loaded (minus the receiver) it weighs 16+ pounds.i just wanted to say thank you for all your help and wish me luck
nickademuss (author)  jonathan19761 year ago
your welcome, strange you couldnt get the glue to stick, it wasnt foam safe CA was it, that stuff is weak. And you ran a torch over the plastic to burn off the oil didn't you?
yanadica2 years ago
how does it turn
i didn't make this instructable, but almost all radio controlled airplanes of this size use servomotors to move the ailerons, rudder, and elevator to turn, the same way a full-size airplane does. to initiate a coordinated left turn, you give left aileron and rudder, then slowly increase rudder while bringing the aileron stick back to neutral, using the elevator to prevent it from nosing over. you then neutralize the rudder, and give a bit of right aileron to bring it back to level. do the reverse of this for a right turn.
Herminator2 years ago
Wow this is awesome! Planning on building this when I finish year 12.

I noticed in the Parts list that the Gas tank conversion kit, it says in the specs (do not use with Flextanks) but the tank in the parts list is a Flextank. Is that an error or does that tank hold up to gas?

One more question, I only have access to 900x600x3MM thick coroplast, would that be ok for the whole plane including the top and bottom of the wing?
BTW I will be making a two piece wing for easy transport with a small wooden spar in each wing plus a removable metal tube that goes into both wings so they don't fold.

I was actually already thinking of making a cub with a 25cc weedwacker engine then found this incredible instructable, made my day!

Thanks for your time! :)
nickademuss (author)  Herminator2 years ago
Oh he fuel tank....the tank itself works fine, the stopper and tubes that come with are not gas safe, the conversion kit makes it safe...
So i can now get a hold of 5mm and 3mm coroplast in 900x600mm sheets, its already underpowered with the 25cc weedwacker, do you think 5&3 for the wing would be too heavy?

Also i have already purchased five of these for the wing/throttle.

Would this be a suitable servo for the tail surfaces?

Just wanna make sure before i go ahead and start building :P.
nickademuss (author)  Herminator2 years ago
The rudder dont need as much power as the elevator, I would go at least 100 Oz torque on it. Thats the only way you will be sure to get enough control in a crisis situation.

!8cc was underpowered, 25cc tuned was pretty good, 35cc would be great :)

As to the thickness you plkan on using, it will work, but it will be slightly heavier and hard to fold.... 2mm top wing was easy to build...
nickademuss (author)  Herminator2 years ago
I used 2mm for the top of the wing because it curves and bends easy, 3 mm may be to thick for that, the rest could be made with 3mm though it may not be as ridged as 4mm for the hull and bottom of the wing.

I tried to make a two piece wing once, the problem you will see is that when you make a long wing it gets much more support from the long length of coroplast on the bottom and it stops the flexible plastic from giving. The two pier one I made with an aluminum pipe for a center spar let the whole wing flex allot so much I was afraid to fly it. You might have better luck!

Thanks for the comment! Ad good luck
donphipps3 years ago
Is there a set of printed plans for the large scale cub.
What a nice looking plane, I have been in RC for years but got out of it when I started to fly a Powered Parachute but seeing that I am getting older and retired and thinking I might have to give that up and I don't want to give up flying. When I was fly RC i built a BalsaUSA 1/4 scale cub which had a 108 inch wing span, I feel this is a good starting point.
nickademuss (author)  donphipps3 years ago
Their are measurements in this instructable, no plans per say. Just keep reading, its not like balsa were you build on prints, this is mush simpler.


Oh this one will not fly like balsa, its heavy, it will fly like the real plane.
Thanks, I noticed the dem. when I downloaded the plans. Looking forward to start building.
Tweakster3 years ago
thanks again Zac for this Instructional

for other builders I sent Zac 20 bucks for a case of beer but he said he is using it for Hobbies, would be nice if others could do the same as I think The Great Brain of Planes deserves to have us pay for his Plane

Believe U me I appreciate this...
nickademuss (author)  Tweakster3 years ago
your the best mate Cheers!
Tweakster3 years ago
so what is prop size?
nickademuss (author)  Tweakster3 years ago
it varies for whatever engine you use, but a 16x6 to 18x4 would be a good starting point, you want max rpm, so you may have to try a few to get it...
donphipps3 years ago
trying to figure out how to download the plans to build the cub, need help
nickademuss (author)  donphipps3 years ago
you should see a .pdf icon at the top click on it and it will let you download, if your a member....
Mr.NHRA5 years ago
This is very nice. Did you train to fly on a simulator? If so which one? I am just getting started in model air planes and I want to know the basics before I go and crash a plane. Thanks.
nickademuss (author)  Mr.NHRA5 years ago
I am self taught, I used a very crash resistant airplane to learn on, the Air Core Trainer, and I started out with FMS the free simulator. My Dad got me a cable to connect my radio to the PC and I got my bearings that way. I crashed the trainer a few times and lost more than one propeller but it kept on flying. I have also uses Aerofly a cheap alternative to RealFlight.
Wow nickademuss I admit you are really into RC.
Few RC flyer self taught rarely succeed because they would have crash so many times during their learning curve and usually give up half way.
Nice Piper cub!
I love coroplast aircraft and have design a few usually electric.

This one is a scratch built racer at

nickademuss (author)  babylon53 years ago
Thanks! If I flew balsa at the start I would of gave up.... but plastic lives to fly again and again!
        Im surprised you could start on nitro i still have difficulty flying my super cub with act off , anyways just curios but why is nitro harder to learn than electric anyway?
Heh, when I started flying, there was only methanol (nitro) and diesel engines.

You adjusted the compression of the diesel with a lever on the top of the cylinder.

Absolute b&&$er to start by hand!!
lol yeah I have nitro now....... you can hear me cursing across the parking lot when the battery on my starter dies.....
I had the aircore 40, great little trainer, Very relaxing to fly
nickademuss (author)  randallpw3 years ago
good aircraft, I had one of those and now have a colt
where do you buy Aerofly anyway never herd of it
nickademuss (author)  finnrambo4 years ago
just do a search, its out there, free on some download site, their is also FMS, its free as well, just google...
 the nextar select rtr is the best ever
That is really cool. Thanks for the help.
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