Three days after the design was done, the 20-foot cargo plane was a pile of foam and lumber. Week 1 is where the plan met the shop: wing spars snapping on knots, a fuselage that came out longer than the truck, a workbench that bowed the airplane, and foam board that was half an inch smaller than the label said. By the end it had spars that held a person, a straight fuselage, a nose, and a tail — and still no ribs, motors, gear or electronics.
The design episode could ignore things a real shop cannot: lumber has knots, tables are not flat, foam comes in the wrong size, and a 20-foot wing still has to fit in a truck. So this week was never about following a finished plan. It was about finding out whether the plan could survive contact with reality, starting with the part that could destroy everything if it went wrong — the wing.
The spar has to carry the airplane, four motors and nearly 20 feet of wing without becoming too heavy to fly. Boards were ripped down with thicker pieces in the center section, where the load concentrates, and thinner ones outboard — a straightforward trade of strength for weight. Then the wood started breaking. The spar design was probably fine; the lumber was not. Several pieces had big knots exactly where long, uninterrupted grain was needed. Someone suggested plywood; Eric stuck with wood and picked cleaner 2x4s. Once glued up, the first full-size spar held his entire weight. That doesn't prove a 20-foot airplane will fly, but it was the first evidence of a structure that might survive.
A test rib came off the Bambu Lab A1 mini, but that machine is too small for the production run a 20-foot wing needs. OMTech had a laser cutter on the way, so the plan pivoted: finish the fuselage now, cut ribs when the laser lands.
The fuselage is essentially a giant foam box in 1-inch foam — stiff without heavy internal framing. "Simple" stops applying when the box is longer than the work area. A gap appeared that looked like a bad cut; it was the workbench bowing in the middle and forcing a visible curve into the fuselage. The airplane had become so large that the table, not the cutting, was the tolerance problem. Assembly moved to the concrete floor, the only surface in the shop big and flat enough.
On the floor the next problem showed itself: the fuselage measured 163 inches. The truck bed is 162, and 156 would have been comfortable. An inch too long is not a transportation plan, it is optimism. From that point on the wings, the tail, and probably the nose had to be removable if this thing was going to make it to Flite Fest.
The nose was going to make the crate look like an airplane, and the material was already wrong: 5 mm foam board from the hardware store sold as 24 by 48 that actually measures about 23½. Half an inch sounds like nothing until it runs the full height of the nose and shifts every seam, and shrinking the fuselage was no longer an option with so much of the plane already built. The flat profile was easy; turning it into a curved, three-dimensional nose became tape, hot glue, formers, freehand and an educated guess, until Eric stopped chasing perfect measurements and worked with the shape the foam wanted to hold. After it sat outside in summer heat he did not trust hot glue alone, so Gorilla Glue gussets and an internal brace went in — and the nose stayed removable in case the truck measurement was wrong.
While the H2D spent more than a day printing one 12-inch main tire (which, it turns out, bounces), the tail wheel was built from cut plates, bearings, a steel axle and a pivot mount — Eric's favorite part so far because it had the most time in it. The tail spars then had to be glued at a compound angle for a swept tail, the rudder was traced from the Fusion sketch onto foam board and folded like a Flite Test wing, and the elevators got wood mounted at the hinge line so hinges could be Dremeled in and epoxied. The reasoning is the same one that runs through the whole series: a failure in the sky would be devastating, and far better to be shot down by a sky full of planes than to go down because it was built poorly.
With Preston on a FaceTime call to see it, the pile of parts finally stopped looking like building materials: spars that hold a person, a straight fuselage, a nose that exists, a tail that gives it a shape. Still missing: dozens of ribs to finish the wing (waiting on the laser), four motors, the rest of the landing gear, the electronics, and proof the airplane can leave the shop. Eric had figured out how to start a 20-foot plane. He had not proven he could finish one, and definitely not that it would fly.
Disclosure: OMTech provided the laser cutter; Hot Wire Foam Factory provided the hot knife and StyroGoo. OMTech, Bambu Lab and Hot Wire Foam Factory links are affiliate links.
| Bambu Lab H2D | Printed the 12-inch tires and rims — one main tire took over a day. Printers and materials · which printer for RC. |
| Bambu Lab A1 mini | Cut the first test rib; too small for the production run, which is why the laser took over. The A1 mini in the gear list. |
Nothing to correct here — the write-up matches the video. The ribs, the laser, and the take-apart tail are Part 4, Build Week 2. Spot something off? Tell me.
Auto-transcribed from the video, so expect the odd mis-heard word. Here so you can search or skim what was said without watching.
Hey, welcome to my nightmare. This is this giant 20-ft airplane that we're building. See why it's been so annoying to build so far. 3 days ago, this was a pile of foam and lumber. Now, it's supposed to become a 20-ft RC cargo plane. But, almost immediately, the wood holding the wing started snapping in my hands. The fuselage grew longer than the truck I needed to carry it in. My workbench started bending the airplane, so that's a problem. And the foam for the nose was a half of an inch too small. I apparently need to go to bed. I don't even know what this thing's called. By the end of this build, I wanted this pile of parts finally start looking like an airplane. Question was whether I could solve each problem before the project fell apart. I already spent the last video designing a
C-130 inspired cargo plane for Flight Fest. But, a design can ignore things that a real shop cannot. Lumber has knots, tables are not perfectly flat, foam comes in wrong sizes, and a 20-ft wing still has to fit inside of a truck. So, this video was not going to be about following a finished plan. It was going to be about finding out whether that plan could survive contact with reality. And the safest place to start was the part that could destroy everything if I got it wrong, the wing. I ripped down these boards for my wing spar. Got some thicker ones for the center section, thinner ones for the outer. The spar's the backbone of the wing. It has to carry the airplane, four motors, and nearly 20 ft of wing without becoming so heavy the plane cannot fly. I
used heavier pieces in the center where the most of the load would be concentrated, and lighter pieces towards the ends. it was a simple compromise between strength and weight. But, then the wood started breaking. I noticed that like not some of them are really weak. Right here. Yeah. If this plane was going to work, the spars had to be strong. The spar design was probably fine, the lumber was not. Several pieces had large knots exactly where I needed long uninterrupted grain. Someone did suggest using plywood. I'm I'm to try to stick with this. So, I'm just going to pick some cleaner 2x4s.
Oh, no. I'm bleeding. Okay, I've marked the cut. Let's get them put together. I'm very curious to how strong it is. And that's all my weight right there. The first full-size spar held my entire weight. That did not prove a 20-ft airplane would fly, but it was the first evidence that we had a structure that might survive. Now that I've gotten a couple of these here glued up, this is going to be the main wing spars the rear spar. But now I need to make a bunch of ribs to go along here to actually form the wing around. And this is one that I cut out on my Bambu Lab A1 Mini 2D, but the machine is
definitely a little bit small for the large production volume that I'm going to need. Thankfully, my new friends over at Omtech are hooking me up with a laser cutter, and it's going to arrive in a couple of days. So, I think I'm going to pivot, try to get the fuselage finished up. And hopefully by the time I'm ready for these ribs, the laser cutter will be right there. The fuselage was essentially a giant foam box. But the word simple stops applying when the box is longer than your work area. I used 1-in foam to keep it stiff without filling the inside with heavy framing.
Oh, no. There's a big gap there. Did I cut wrong? Well, I tried a bunch of different sides and investigated further, and I realized that my table actually is bowing in the middle. You can probably see that giant curve. The airplane had become so large that my workbench, not my cutting, was now the tolerance problem. A slight bow in the table was forcing a visible curve into the fuselage. It's not going to cut it. Um it's going to have to transition to building on the concrete floor. The concrete floor became the only surface in the shop large and flat enough to finish assembling the fuselage. But assembling it on the floor revealed another problem. Uh it's it's going to be massive. Like, "Okay, where's the steering wheel?"
But I laid it out and I realized that the thing is it's currently a little over 10 ft. But I think I can shove it up in there a little bit more. Moment of truth here. 163 in. So, if this doesn't work, I'm going to have to make the nose detachable, and that is 162 in. And we said 156 would have been nice, so it's going to be so close. Well, if the math saying the fuselage is going to be 6 in too long, that is not a transportation plan. That is optimism thinking that might work somehow. From that point on, the wings, the tail, and possibly the nose is going to have to be removable if we think we're going to get this thing to actually make it to Fight Fest. Editor Eric here. If you're enjoying this video so far, it
would mean a lot to me if you would hit that subscribe button. I'm trying to hit 100,000 subscribers by the end of the year. I know that's a crazy goal, but you guys are awesome, and if you would love to support me along the way, hit that subscribe button, like this video, leave a comment of what you liked about it, and let's get back to the build. And after taking a quick break to check in on the sweet tires and rims that I'm 3D printing on my H2D, I decided I should start working on the nose. I know I'm all over the place, but I wanted to try to build this nose for this video because I want to see what it looks like, and I'm sure you guys do, too. The fuselage could finally support itself, but it looked more like a shipping crate than an airplane. The nose was the part that would finally make it recognizable, and the material was already wrong. So, I'm not sure what
I'm going to do for the nose. This uh some 5-mm foam board from Home Depot. They say they're 24 by 48 sheets, but they're not actually. They're actually like 23 and 1/2. Half of an inch sounds insignificant until it runs across the full heights of the nose and shifts every seam. Shrinking the fuselage was no longer an option because too much of the plane already existed. So, you can see the frustration when I have a 24-in airplane. You can see there's a gap on each side. Now I have a big gap up there. Okay, so we'll see if this is a good decision or not, but I'm going to try to just cut this to exactly 24. So, we got that there, which will it work? Who really knows?
I never thought we'd make it to this point, but look at it. The nose is right here. I just used hot glue for this, and I think it worked pretty well. I can tell you it's big. That was a bad idea. Maybe I'm going to go back with Gorilla Glue and put like some gussets there just to strengthen that. The flat profile was easy. Turning into a curved three-dimensional nose became a mixture of tape, hot glue, free hands, formers, and an educated guess. Eventually, I stopped trying to make every measurement perfect and started working with the shape the foam actually wanted to hold. Do I look small next to this airplane? Or is this airplane just massive? The shape worked, but I did not trust the hot glue alone after the airplane sat outside in the summer heat. I added
Gorilla Glue gussets and internal brace. I also kept the nose removable. If the truck measurement was wrong, those few inches might save the transportation plan. And then if I don't need to remove it, I can just leave it attached. So hard to appreciate the scale of this thing, But it is literally huge. So my next step is to get the tail done on this thing. So hopefully it'll start looking like an actual airplane here. And while the printer spent more than a day producing one of the main tires, I built the smaller tail wheel assembly from cut plates, bearings, a steel axle, and a pivot mount. It's looking good. I'm excited about this part. Honestly, this is probably my favorite part so far cuz I put the most time into this right here. So maybe I should put some more time into the tail. So we got our wing spars all cut out here and I was about
to glue them together and then I realized that they kind of need to be at an angle because I'm trying to do a swept tail. This is going to be a pain in the butt. They need to be glued together at like a complex angle, probably like that, so it'll all line up properly. So I've got the spars mostly done. These are for the rudder. I'm basically going to take my sketch here from Fusion, all the dimensions. I'm going to trace it out on some foam board and I'm going to make two of them from together at the hinge point and then we're going to fold it together like a big flight test style
wing. So Preston just texted me saying he was going to jump on a FaceTime call here in an hour. So that means I got an hour to finish the whole plane. So you want to see the plane? Despite all my efforts in recording in three places, I somehow didn't get audio from him. So I'm just going to have to try my best Preston got. It's a little bit big. Oh my, that thing's huge. I don't know how good it come across like on video, but it looks Oh, it's
coming across. It's coming across. And after that, I showed him the strong spars that I made, the shop where I built the plane, and the model that I had made so you can see all the ribs. Showed him the giant motors, the servo control horns, the giant wheels that I'm currently 3D printing, the tail wheel that I made from scratch, and my favorite part of all, a parachute guy. After showing him how we're going to get the plane to flight fast, I decided to get back to work on it. All right, talk to you later. Bye.
Good morning, everyone. This printer over here is still chipping away at this wheel. It is making some good progress. Meanwhile, this glue dried up overnight, so I'm going to make the final airfoil shape. So, let's get to it. All right, let's see what it looks like. Yeah, this is a big runner.
Here's the elevator pieces cut out. I'm going to cut out two more of those. And it's huge. Man, this thing is coming together. We've got our main spar and our rear spar. I didn't think it was worth putting ribs in all that complicated stuff inside of here. I mean, this is the hinge. So, I think I'm going to mount some wood there. Then I'll be able to Dremel into that wood and and epoxy some hinges in there, and they'll be super solid. Cuz that's what we want. We don't want a failure in the sky. That would be a devastating. I would much rather see a bunch of planes take this thing down than it go down I just built it very poorly. So, let's get this thing glued up. And
This thing looks awesome, and it is super lightweight, and hopefully it's super strong. So, I'm sure you guys want to see it on the plane, right? Done. It's done. It's done. It's done. This thing is a beast. Wow. How did I just 3D print a tire that bounces? For the first time, the parts stopped looking like building materials. Well, this is the big plane. You think it's big enough? This thing is massive. The wing spars held my weight. The fuselage was straight. The nose existed. And the tail finally gave the airplane a recognizable shape. But, the most important part was still missing. The
new laser cutter would let me build dozens of ribs needed to finish the 20-ft wing. After that, I still had to mount four motors, finish the landing gear, install the electronics, prove the airplane could actually leave the shop. So, I had to figure out how to start building a 20-ft RC plane. I still have not proven that I could finish one. And I've definitely not proven it would fly. Thank you guys so much for watching this video. It really mean a lot to me if you hit that subscribe button and like this video. I can't wait till next week when we hopefully get most of this plane complete, and I will see you then.
