A completely custom cargo plane — no plans, just foam board and trial and error. One sheet became the fuselage, four layers of foam became the spars, and a taped-on hatch became a cargo bay. Then came the maiden. Here's the full story, plus the spec sheet to build your own.
Everything below is on the printable spec sheet — dimensions, electronics, CG, and my transmitter settings.
| Wingspan | 79½ in (202 cm) with tips | Motor | FT Radial 4030 510Kv |
| Length | 62 in (157.5 cm) | ESC | Hobbywing 100A |
| Weight | ~2600 g (5 lb 12 oz) | Prop | Gemfan 20x13E two blade |
| Material | Rediboard 5mm foam board | Battery | Graphene 5000mAh 6S |
| Wing | Flat bottom, rubber-band mount | CG | ~2 in from leading edge |
The whole fuselage starts as flat 20×30 sheets: score lines, fold each one into a tube, glue. The rear tube gets an angled cut so the tail section tilts upward, a little triangle notch locks the tail in snug, and the servos live inside the fuselage with control runs back to the elevator and rudder.
Then the fun part — it's a cargo plane, so it needs a cargo bay: I cut a box out of the belly, taped the removed piece back on as a hinge (foam board's cheapest hinge), added a release servo up front, doubled the door with an extra foam layer, and padded the bay so cargo can't shift in flight.
Why it fits: the fuselage folds up from flat 20×30 sheets and each wing spar is four foam layers thick — a build this size goes through a stack of board.
The spec that matters: 5 mm paper-faced board, same as the spec table's Rediboard — the sheet material stays the same as a small plane, you just use it in multiples.
If you scale up further: lift scales with wing area, but weight scales with everything — a hauler wants a thick wing and a modest wing loading.
The wing is where a cargo plane earns its name. I went back and forth on spar thickness because I wanted a thicker airfoil — a fatter wing section generates more lift at the slow speeds a hauler flies at. Each spar ended up four foam layers thick, which sets the airfoil height and carries the wing loading. Both halves fold from single sheets, with 8-inch tips on each side and dihedral built into the center joint for self-leveling stability.
Why this matters if you're designing your own: lift scales with wing area and airfoil, but weight scales with everything. A hauler wants a thick, generous wing and a modest wing loading — exactly the trade-off the Airplane Designer shows you when you pick the Cargo/Scale style.
The first flight was rough — flyable, barely, but temperamental. Back at the bench I made the changes that transformed it:
Why it fits: the FT Radial 4030 510Kv "monster motor" on 6S had grunt to spare even while everything else was temperamental — this ~500Kv large-outrunner class is the same territory.
The spec that matters: a ~500Kv outrunner on 6S swinging a big two-blade (I flew a Gemfan 20x13E) — that combination hauls a ~2600 g airframe.
If your version flies temperamental: check the CG before blaming the power — moving mine a couple of inches back is what transformed this plane.
Flight two felt smooth almost immediately — wide level turns, good tracking, even a hands-off moment. Not the sportiest thing in the sky, but "not bad for a little cargo plane." A few honest notes from the flight log:
Why it fits: the as-flown ESC is a Hobbywing 100A — this 60–100A class covers the same 6S power system.
The spec that matters: the amp rating. Big planes pull big currents, and wiring or an ESC that's marginal on the bench fails in the air.
If you see smoke in flight: land immediately and inspect — that's the drill, and the glide tests right after mine proved the airframe was fine.
The spec sheet has everything: dimensions, the full electronics list, CG position, and my transmitter settings (mode 2, 30% expo, 70% dual rates). Scale it to your own size with the Airplane Designer, and document yours with the Spec Sheet Maker.
Why it fits: the spec-table pack is a Graphene 5000mAh 6S — this 5200mAh 6S OVONIC is the same class, in stock.
The spec that matters: 6S — the voltage the whole power system (the ~500Kv motor, the 100A-class ESC, the 20″ prop) is built around.
If you move or resize the pack: the CG moves — this plane balances about 2″ from the leading edge, and a couple of inches of CG was the difference between a temperamental maiden and a smooth one.
| Type | RC park flyer |
| Wingspan | 79½″ (202 cm) |
| Length | 62″ (157.5 cm) |
| Wing chord ≈ | 12″ (31 cm) |
| Weight | ~2600 g (5 lb 12 oz) |
| Material | 5 mm Readi-Board foam |
| Wing | Flat-bottom, rubber-band mount |
| Fuselage | 4×6 box-style profile |
| Tail | Conventional |
| Control surfaces | Elevator, rudder, ailerons |
This build kept living after the upload — here's what happened next.
Auto-transcribed from the video, so expect the odd mis-heard word. Here so you can search or skim what was said without watching.
In this video, I set out to build a completely custom five foot wingspan cargo plane from scratch. No real design, just foam. The goal? A high lift platform that can carry real weight, but it didn't go all smoothly. I'll take you through the full build process, the first flight, which didn't quite as planned, and the changes I made along the way to make it better.
Whether you're into RC planes, scratch building, or just want to see a wild DIY project come to life in the sky, this one's for you. Let's get into it. Okay, so we're starting out with one sheet of foam board here, and I'm just laying it out to make a tube for the fuselage, all from one single sheet of foam board. I'm cutting out the score lines first, so we can fold it into shape, and then we'll start gluing it up. For the rear section of the fuselage, I'm cutting an angle into the second tube, so it tilts upward a bit, and that'll give us the shape we want.
Now we can move on to the tail. I'm cutting out the elevator with just a few simple angles and scoring a control line so it can move. Then we'll do the same for the rudder, nothing fancy, just cut it out and make a control surface. Time to marry everything to the fuselage. I'm cutting a little triangle into the back so the tail section fits in snug and stays sturdy.
Finally, I'm adding the servos inside the fuselage and running the control horns back to the tail. Alrighty, so the plane is coming together very well here. We've just got to fish these wires, so we put our servos right there inside, ran them back there, that's the tail going on. So now I'm just gonna fish these wires through here, and then I think I'm just gonna permanently glue this back on here, because I don't really need it in there again. And then we're gonna go ahead and we're gonna attach our front tube, which goes right here, and then we're gonna make our cargo, like cargo drop section in this front tube.
It's happening, it's coming together, and then we can jump to the wing, let's do it. So I'm cutting out a small box in the fuselage to create a cargo bay door. I'll tape that foam piece I removed back on to act as a simple hinge. Up front, I'm installing a servo for the release mechanism, and I'll probably redesign this later so I'm not getting too attached to it, but for now, I've reinforced the door with an extra layer of foam for added strength. I also added foam padding to the front and the back inside the fuselage, just to keep the cargo from shifting around too much.
Alrighty, it's all glued together. I got the Bombay door kind of put in there, and this thing is looking huge. Just let's move on to the wing. This wing is massive, I feet wide, so I need to clear off my table a bit to make room for the foam. I'm starting off by building the spars.
I went back and forth on how thick to make them because I wanted a thicker airfoil to generate more lift. Since this is a cargo plane, it needs to carry a decent amount of weight. I finally landed on a design I'm happy with, I think. Each spars reinforced with a second layer of foam, so in total, there are four layers of foam in each one. Hopefully that will also provide the strength we need to support the wing loading on the wing.
From there, I added the score cuts I needed to fold the leading edge into this single sheet of 20 by 30 inch foam board. Once both sides are done, the full wing span will be about 60 inches, plus an additional eight inch wing tip on each side. I'm cutting those tips now, keeping it simple with a basic shape. Next, we'll glue the spars in place and start folding together the rest of the wing. Okay, so the wing is looking like it's coming together.
We just gotta glue it up now and fold it together and that'll form our wing and then we can marry the two together and we are coming real close here to have it in airplane. Now that both halves of the wing are complete, it's time to start assembling everything into one full wing. The first step is to tape and glue the two halves together at the center joint. This will let us fold over the foam and form the full airfoil shape. While doing this, I'm also building in the dehedral.
This is a slight upward angle of the wings from the center which helps the plane fly more stable, especially in turns. I'm aiming for about six degrees of dehedral here. That may not sound like much, but it makes a big difference in flight performance. It gives the wing a natural tendency to self level, which is especially helpful in large cargo planes like this one that aren't built for aggressive aerobatics. Forming this airfoil is a bit tricky because it's pretty steep.
I wanted a thick height profile for better load capacity. That means folding it over smoothly takes some work in patience. The foam naturally wants to resist, so I take my time aligning everything carefully before committing. I'm gluing the wing in stages, starting with the airfoil shape, the dehedral, and then finally the wingspar because the hot glue gun can only handle so much at once. If I tried to glue the entire wing in one go, the glue would start cooling before I could press it together.
Breaking it into smaller sections ensures each part bonds solidly. After aligning the center joint and creating the dehedral angle, I added a wooden spar right in the middle for extra strength. This adds stiffness to the wing and helps distribute forces evenly during flight. I glued that in and came back and sealed up the wing structure all the way. Once the glue up was done, I stepped back to check everything.
The wing close up looked really nice. It had a clean profile, a solid feel, and the angle looked good. I'm really happy with how it turned out for such a large wing with such a deep airfoil, it came out surprisingly well. The structure feels strong and ready for the next step, adding the control surfaces and getting it mounted to the fuselage. Alrighty, so I put the battery and the motor up here and determined the wing needs to go about right here to get my center of gravity correct.
So we're gonna glue the wing on now and we'll be pretty much done. Alrighty, so I'm gonna get the motor mounted and get some ailerons on this thing and we are gonna get this thing in the air. So the ailerons are pretty straightforward. I'm literally just cutting a rectangle on each side of the wing that I can add some servos to control our control surfaces through some three-parted control horns here. For the motor mount, I'm just using a piece of quarter inch plywood and then screwing our flight test radio monster motor to the plywood, routing our wires through to the ESC inside.
Putting the ESC inside was kind of a pain just because my hole there you can see is very small. So it's kind of cramped to get all the electronics inside but we got everything wired up and now I think it's working very well. I got some programming done and I'm also getting the door here so that I can open it back up again with a piece of tape just creating like a little latch there. I'm adding a battery strap and a spot for the battery to mount with a piece of plywood for reinforcement. So we got the wing on the plane here.
We've got about ready to put landing gear on it and then we can get it in the sky. So let's do it. Okay, so this is what we ended up for a landing gear situation. I've got some little foam pieces holding my landing gear. This is actually landing gear from the FT Scout XL.
So that's what I'm using here but the real test is gonna be if it'll actually clear the prop. So let's put this on the ground now. And let's put this prop on. And the answer is just barely, look at that. That's not, that's a little too close for comfort for this big of a prop.
I don't want a prop strike. So we're gonna see if we can think through some options but that's looking good. I also got the little hatch door, little Bombay door there. A little bit better put together. I'm gonna flip my switch here, door opens and I put this little plastic piece here to catch the servo.
And I think it actually worked out very well. So let's get this puppy up in the air. Okay, made a voyage, let's take off. One supply is so bad. Actually a little tail heavy.
So I wanna do a little segment here called Gospel in Flight. As I watched this plane take flight for the very first time I reminded of the words of it, they have 40, 31. But those who wait on the Lord shall renew their strength. They shall mount up on the wings like eagles. They shall run and not be weary.
They shall walk and not faint. When we put our faith in God, when we truly trust in Him, He renews our strength. He lifts us above fear, above sin, above discouragement. Just like the plane was built to fly, we were created to rise, to soar with purpose. We weren't meant to stay grounded in the things of this world.
Alrighty, let's try our bomb drop before it's too late. Bombs away. Hey, it worked great. So if you're feeling down today or stuck, remember God has more for you. Wait on Him, trust in Him and let Him lift you up.
For His plans for you are greater than anything you can imagine on your own. Don't be afraid to let go of the runway because with God, you are meant to fly. Alright, let's bring it for landing. Oh, it's going a lot faster than I thought it was. It's a lot bigger than I thought it was.
Oh, yeah, let's go get it. It was kind of unstable in the sky. I'm not sure why. I feel like I'm not just having enough control. I think I do want to change the P factor on the propeller because I know that propeller is huge and there's probably a lot of P factor effect coming into place here.
I think that's a good idea. I think that's a good idea. I think that's a good idea. There's probably a lot of P factor effect coming into place here. So we should definitely do it a couple of degrees, an angle on there, which we do not do in the first place.
So I determined that my issue here is probably center of gravity. So I think I'm going to try to shift the wing actually backwards because I've got a pretty stubby nose here if that helps center of gravity. Because I think it was a little bit tail heavy in the sky and that's why it didn't fly super stable. So hopefully we can make this change and it will fly a lot better. So I'm basically going to cut out a couple of pieces of wood here to act as popsicle sticks to support our rubber bands.
And then we're just going to install them, glue them in place, and then rubber band this wing on. All righty, so things are happening here. We've got ESC mounted on the outside now to get better airflow. I did add some washers there to help the P factor. This is upside down, by the way.
So maybe I'll just flip it. So that is mounted right there. Motor is good. We've got some washers in there. This is the strap for the battery.
I got some mounting points there and I'll show you why. So I'm going to use some rubber bands to hold the wing on. And I think that'll work. It'll be a solid, secure mounting point. And if we need to move it in the future, it'll just make it a little bit easier.
And the other thing is, I guess it's easier for transport. But I moved it back. What is that? Probably two inches there. So hopefully that'll help with my center of gravity problem.
So we are going to try to fix this landing gear issue now. So hopefully we can get that resolved. And hopefully this thing will be flying a lot better and much more reliable. So admittedly, the landing gear just wasn't great. So what I'm doing here is I'm making some reinforcement plates to go inside of the fuselage to strengthen it.
So the landing gear will slot into these reinforcement plates and hold it in there way better than just the glue can. Because the landing gear kept sliding backwards. Because you can see there, our wing is pretty securely mounted. It's not going anywhere now. This here is pretty secure in there now.
I added this little reinforcement. You can see inside of there. So now this is too all thick and that's embedded into it. So that's not hopefully going to go anywhere anymore. And then, yeah, that looks like that still.
And I think we're ready to get the spatter charged up and get out there for another test flight. All righty, winds are fairly calm right now. So we'll see how she does. She wants to fly. So you can see how close my landing gear is very close to the center of gravity.
So like any pressure on it just wants to tilt it forward, which is not great for a pripe strap. Prop strikes. So I'm going to have to just pull on the elevator and make sure that it comes up before it hits the ground. Not ideal there. All righty, flight attempt number two.
Here we go. Watch how fast this will take off. But it'll just be like right in here. Oh yeah. Oh yeah.
Feeling good already as we're getting in the air. Feeling nice and smooth and definitely a little bit better than the last time. Power with that monster motor on there. It's the FT radial monster motor. It's definitely a little bit still wonky to control.
We'll trim it out a little bit here and hopefully it'll be a little bit more smooth as we go in this flight. But it's already looking really good. It's doing fantastic. And the hydro is definitely helping here. I definitely feel that our center of gravity is much better where we put it.
There's a couple inches back. Definitely helped a lot. Trying some nice wide turns here, keeping it level, doing some different flights, movements and stuff. And it's doing pretty good, all in all. Not bad for a little cargo plane, not the most sporty thing in the world.
But not bad for a little cargo plane here. Still trying to get a feel for it. I feel like there's some kind of like weird right. Just trying to keep it high in the sky here because it is a little bit temperamental. As I'm trying to do some tests here, I want to keep it three mistakes high so that I have a problem I can have time to fix it before I crash into the ground.
It's been sometimes like right now. I could use the rudder to get any roll out of the thing, which makes no sense. It's still like kind of very temperamental. It's flying better, but I still feel like I'm going to crash every two seconds. I think this point is going to be super awesome.
It's going to be able to hold a ton of weight for sure. So let me know in the comments what you want me to drop and I will see what I can do. Hey, I'm hands off right now. It's like a great split plane. But all in all, this thing is tracking a lot better.
And it's flying fairly smooth, the most part. You just need a big area to fly it in. Pretty big plane. You're a little higher on my cup of throttle. Oh, no.
It's a smoke. One could not fit. Just trying to do some glide tests here. And it's gliding pretty well, actually. It's doing some nice slow movements.
And wow, that thing's big. Let me get close to it. OK. OK. Well, I think we got our test flight number two in for the day.
It's flying pretty good. We're going to see what we can do to make it better. But if you like this video, hit that like and subscribe to my channel. And check out some more of my videos. See you in the next one.
Adios.
