Introduction: Homemade Aircraft for Under $1000 (FlugTag Style)

Picture of Homemade Aircraft for Under $1000 (FlugTag Style)

I am an Aerospace engineer and a pilot, and when the RedBull FlugTag came to my town, it was the perfect opportunity to put all my skill to use. This instructable walks you through the entire process of building your very own plane. You don't have to design it the same way we did, in fact just about anything will technically fly if you get it going fast enough. The aircraft described here is actually a Ground Effect Vehicle. This means that it's designed to fly a maximum of the wingspan from the ground. The advantages of this are that it's very safe, very slow and requires a very small power supply. If you live in the desert or anywhere near water then this is perfect. Add a bigger power plant and you can escape ground effect and go as high as your engine will allow you.

While you can source some of the materials form your local hardware store, others will be nearly impossible to source locally or they will cost you much more. You can probably build everything by yourself, but it's going to take even more time and most of the fun in this is the teamwork. We spent 3 months building the first version, but with this instructable, you should have a working plane in less than 160 hours of work. (That's about a month if you make do this full time by yourself.) Actual cost of the materials for the plan is about $500 but you might need some tools. Cost of the power plant can be $500 to $10,000 depending on how fast you want to go. Or just use it as a glider for free.

Step 1: Order Your Supplies

Picture of Order Your Supplies

You're going to need several key items:

  • 1" T6061-T6 Extruded Aluminum Tubing (Online Metals)
  • 3/4 T6061-T6 Extruded Aluminum Rod (Online Metals)
  • PIC Foam (Lowes or Home Depot)
  • Rubbing Alcohol (Walmar)
  • Gorilla Glue (Lowes or Home Depot)
  • 3M 3050 Tape (Lowes or Home Depot)
  • Loctite Spray Adhesive (Lowes or Home Depot)
  • 4x8x1/4" Luan Plywood (Lowes or Home Depot)
  • 3mm Lamination Film (Amazon)
  • T-Rex Packing Tape (Walmart)
  • Various nuts, bolts and screws that you can get at your local hardware store. (Lowes or Home Depot

For the tubing, you want T6061 extruded aluminum tubing. You can get 2024 since you don't need to weld anything but it's much more expensive. You can get thin wall, but it's more expensive. At $12.50 per 8' section this is the best value and it's insanely strong. https://www.onlinemetals.com/merchant.cfm?pid=2285...

For the foam, nothing comes close to PolyIsocyanurate board. It comes in 1/2" and up sizes but you want the 1/2" stuff. 2 sheet's glued together with Super 77 weight 20% more than a sheet of 1" but increase strength by 40%. The blue and pink stuff is just filler. It might be easy to cut, but it's flimsy and a waste. You want the silver coated stuff that is usually painted on one side.

Rubbing Alcohol (91%) is will remove that paint and make both sides shiny silver. This takes a few ounces off and also makes your aircraft look like it's made of all aluminum. Bonus!

Gorilla Glue is amazing stuff. It is actually very similar to the foam, expanding into every crevace and securely bonding all of your parts.

3M 3050 Tape is usually sold as air conditioning ducting tape, but this thin and lightweight tape puts duct tape to shame. It's easy to work with and super strong.

Loctite Spray adhesive is for laminating layers together. It's fast, strong, foam safe and easier to work with that Super 77.

The Luan plywood is thin, light, and flexible. When bonded to foam, it's incredibly strong.

3mm Lamination film will serve as your covering. You can use Monokote if you have an unlimited budget, but the clear film is easy to work with and is very strong. It's also easily patches with packing tape.

Packaging tape. To patch holes. You could use anything, but this is an airplane. Use the best.

There is very little hardware. Most of the plane is glued together but you'll want piercing 1 1/4" screws from home depot. A few pieces of 1 1/2" hurricane strap and maybe some screw eyes to run your control lines and tow connections.

Step 2: Gather Your Tools

Picture of Gather Your Tools
  • Heat Gun (Harbour Freight)
  • Lamination Iron (Amazon)
  • Razor Blades
  • Hack saw
  • Tape Measure
  • Chalk Line
  • Sharpie

Yeah, you can get power tools and all sorts of fancy stuff, but we found that a simple razor blade was all you needed to cut the foam. And a Hack saw works just fine. If you have a Dremel tool or a disc sander, it might come in handy.

Step 3: Start Cutting

Picture of Start Cutting

We spent about 200 hours on our plans, doing designing weights and balances to ensure everything was just right. Building models in CAD, printing them out and testing them. Use the template above to cut out your airfoils. You'll need 24 of them. We went with a heavy lifter airfoil that had a 12" chord and was 6' in length. Both the canard and the main wing used the same airfoil to simplify things. We found that making the airfoil out of luan and then using that as a template sped things up a lot. You can use a Dremel tool as well, but it makes a MESS. Be prepared with a mask if you intent to use power tools. For the leading edge, use a 8" wide piece of foam (that you should have leftover from each set of 6 ribs). For the trailing edge, you want a 12" wide piece. Your blocking pieces will be as per the plans. The canard and center section of the rear wing will match, but the wing extension will vary slightly.

Step 4: Assemble!

Picture of Assemble!

You could just put it together with all that painting on your foam board. But if you are willing to put in a little effort, it's worth it. We found that putting on a pair of gloves, getting a rag and putting a spray bottle head on a bottle of 91% isopropyl alcohol make quick work of this next step. Just spray down the foam, wait about 60 seconds and wipe off the paint with firm pressure. Cleanup with some paper towels and you'll have shiny aluminum board on both sides!

Once that cleaned up, you can start assembly. Test fit everything to ensure your spacing is right and that everything is square. Like a house, if you don't have a square foundation, your whole house is going to be crooked. In a house this means that your OCD might kick in, in a plane it means you'll fly crooked and crash. Spend the time to get this step right.

You can cut out everything at once, but unless you have an enormous shop, it's easiest to work with one section at a time. First you'l want to glue the leading and trailing edges on. Spray with water, coat with a very thin layer of glue (that stuff expands about 5:1), fit together and immediately cover with 3M 3050 tape. The tape keeps the glue in the joint, making for strong and good looking connections. After that dries in about 4 hours, put on the bottom aluminum tubing, but don't glue it in place yet. Then insert your blocking, adding water and gluing as you go. Wear gloves because that glue doesn't come off easily. I ruined several pairs of pants before I got good at it. As soon a you're done fitting it all together, tape everything up, then use clamps, straps or heavy weights to hold it all together as best you can.

Once all that is together you'll immediately notice that it's strong, REALLY strong. But it's about to get a whole lot stronger. You want to cover all foam edges with 3M 3050 tape. The main reason is that it will give your covering something strong to stick to, but it also makes the foam stronger and keeps out moisture. This is important, because the one main drawback of PIC over XPS (the pink foam) is that it's NOT waterproof. It will actually absorb a lot of moisture meaning that it will add weight and could mold or even rot. But it also just looks a lot better than un-taped seams.

Now that everything is taped you can build your fuselage. Cut and assemble as per the plans. You'll be attaching the fuselage to the wings with hurricane strap. This 1 1/2" wide galvanized steel is usually used to keep roofs from blowing away, but if you cut it into 8" section with a hack saw, sand it down, drill a few holes and it makes a very strong joint that can be easily adjusted and replaced if there if ever damage to the plane. We tried 3D printed connectors but they were heavier than the steel and not near as strong. Glue the fuselage together with the same water, glue and tape technique.

Step 5: Wiring and Power

Picture of Wiring and Power

At this point you have to make a decision. How are you going to use your aircraft? If this is a glider, then you can skip this step. If this is a lake flying ground effect machine then you can probably go electric only. If you want to fly to 1000' or higher, you're probably want to go with Gasoline Engines. You can do ducted fans, jets, maybe even Ionic propulsion. At this point that bit of engineering is up to you as it is outside the scope of this instructable and I'm testing various thrust systems right now. We pulled it behind a boat and a quad, even an electric scooter. It glided down hills and ultimately won us the RedBull Flugtag so you know it actually flies. But how you power yours is up to you.

Step 6: Cover It

Picture of Cover It

Now that everything is together it's time for the covering. This is probably the most tedious process and you'll probably space this out over several sessions. If you do this during the winter, you'll be much more comfortable because it makes a LOT of heat.

Wrap the coating over the entire wing from trailing edge over the leading edge and back again. Use a bit of packing tape to hold things tight. Then use your heating iron to adhere one side to the rib pull tight and then seam the other side. The tighter you get it, the less work you'll have to do with the head gun later. You want each seam to overlap the rib, going down and seaming the excess to the rib itself when you can and overlapping the next rib by about and inch. The film will stick well to itself, just go slow and ensure it turns completely clear to know that you have it hot enough.

Once the plane is completely covered, or each section if you want, then you can start shrinking. There are cheap heatguns and there are good heatguns. If you want to burn 1000 little holes in your plane and patch them with packing tape, go for the cheap one. Or spend $30 and get a good one. The lamination film turns clear at 300 F and you'll put a whole through it at 340 F. It takes about 100ms for that to happen. Go slow, keep the gun about 8-12 inches away, at an angle and turn the heat to about 750F with the fan on high. This will give you plenty of time not to burn through. But you probably still will burn a few holes. Just be patient, you can keep shrinking so just let it cool and keep going back over it until it's tight. It will get drum tight and perfectly clear when you are done. You also will probably warp your wing in the process, but you can fix that later. You can patch the holes with more film but the T-Rex tape is fast and strong.Once you're done it will look like a plane!

Step 7: Final Assembly Touches

Picture of Final Assembly Touches

Now you have to put it all together. You'll use 3/4 in step bit with an extension to drill 4" into each end of the main wing center section and the two wing extension. Wallow it out well by moving the bit around. Then cut the 3/4" solid rod into 7 1/2" pieces. Fit the sold rod into the 1" tubing. It should insert smoothly. If it's not easy to put the rods in and out, then keep drilling and moving the bit around to widen the hole.

You add the winglets and rudder, bolting them on as per the plan. Then the rudders install between the wing extension and the main wings. Put the rods in and drill a 1/8" hole through the tubing and rod. (Try no to poke and holes in your plane while you're at it!) Then put a 1 1/4" screw into each hole to keep everything together.

Square it up, check your angles and use the heat gun to shrink and straighten out anything. This process can take a while so be patient. You now have a working aircraft!

Step 8: Go Fly!

Picture of Go Fly!

OK, at last you can find out if all your hard work was worth it. You should have a aircraft that weighs around 120 lbs plug engine and landing gear. We started out testing behind a boat but that was a total failure. We then put it on another boat, used 2' leads tied to all 4 corners and pull the plane with a 2nd boat. That worked great and we found that 18 mph was the perfect speed to lift a person and plane into the air. But the real success came with the zip line. We used a 3/16" galvanized steel aircraft cable pulled between two trees across my lawn for 275' at a 6 degree angle. Using turnbuckles we go the line as tight as possible. Connecting the plane to two pulley and the pilot to 1, we were able to perform repeated tests in a safe and controlled way.

Adding wheels we rolled it off hills with just a sandbag in it and had good results. Just make sure that you have solid landing gear or water under you. Our aircraft yielded a 3:1 glide ratio pulling off 81' from a 25' fall in the 2017 RedBull Flugtag. Maybe you can do better? I know we're going to keep trying!

You can read more a tnflugtag.com and follow our us on Facebook at @tnflugtag.com

I'm working on making a complete build process video but it's going to take a while to compile several hundred hours of footage. You can see a lot of stuff on Facebook at @tnflugtag or tnflugtag.com A highlights reel and a complete build video are forthcoming.

This was an early testing video: https://www.facebook.com/tnflugtag/videos/140558703197331/

The notorious lake crash: https://www.youtube.com/watch?v=_Hx-dwXilTY&t=9s

Zipline Testing: https://www.youtube.com/watch?v=5b5VmThmSuE

Just our flight: https://www.facebook.com/tara.holancinhart/videos/10214275566030003/

The official RB video: https://www.youtube.com/watch?v=dppeL1F9oA4

Good luck!

Comments

JjR8 (author)2017-10-07

Do you control this thing by shifting your weight?

mcghan (author)JjR82017-10-07

Actually we had spoilerons, you can see the right one come up to level the craft just before landing. Yes wright shifting is there too but there isn't much time to figure out what to do in 2.5 seconds. We put the pilots 6 inches in from of CG and directly on CL. Seemed to work out well, he could and shifted back about 1/2 way down and probably gone another 30 feet. But he had never flown anything so we just told him to hold on and let the plane for the work. When I flew it in tests, I used weight and controls like I fly a paraglider. But I am 180lbs and he was 120lbs. Weight over skill for the competition.

JjR8 (author)mcghan2017-10-07

Ok, thanks. Would the controls be adequate for powered free flight at higher altitudes?

AeroSpaceWatercraft (author)2017-10-01

Since when did Red Bull allow you to do test flights? Also, when did they drop the ramp height from 30 to 25 feet? I'm also curious if you had ever considered a hang glider design, like the Chicken Whispers team's flight of 258 feet, at the Long Beach Flugtag. Thanks

No where in the rules does it say you can't do test flights. Most people just don't have time, they build theirs just a few weeks before the event. We were done with 6 weeks to spare just to allow time for testing and repairs. The height varies by location, Nashville was supposed to be 22' and they raised it to 25' at the last minute. With 30' we would have had just enough to catch ground effect and set the world record. This is a vastly superior design to the chicken Whisperers, but we only had a 22' wingspan and 25' of height to work with. The cart height is now a 4' high max. A hang glider of equivalent surface area will lose to a low wing every time due to ground effect. The closer a wing is to the water, the more lift you get. The only advantage to a hang glider is that it's more balanced laterally, but far more prone to stalling or nosediving with an inexperienced pilot. A canard will yield a very large CG, and much more consistent results. The main reason we choose a canard was rhat it had more wing for 4 people to push on. I wasnt really a fan when we started, but after a lot of research amd testing, it proved the best. You can use these same techniques to build any style you desire, maybe you can build a hang glider that can do better. There were several well build hang gliders at Nashville and they all did less than 40'.

Well I distinctly remember the 2013 rules for Long Beach saying that you must not only film or photograph the construction of your craft, but no test flights. For me, this made no sense, I protested this, and I was taken out of consideration to participate. For some reason, Red Bull's own website doesn't even have the link to the rules, so I can only guess by your reply that the rules were changed. I wrote to my contact at RedBull to see if they can provide me with the 2017 rulebook, since my aforementioned notion of test flights has been one of the prime reasons to try again, among other things.

As for the rest, you're preaching to the choir, in regards to the technical info and hang gliders, but I still appreciate what you shared nonetheless.

Thank you for taking the time to explain your position.

They gave us a printed rule-book and it didn't mention testing. Nothing was ever available online. We posted our testing video right to the rest of the group as we did it, and it actually made us quite popular at the event. We became known as the "Guys that crashed on the lake." No one complained to us about testing. For all the safety calls they went through, the actual safety inspection was quite tame. We were asked to put some duct tape over the bolts on our wheels. My only complaint was that on the ramp I got into an argument with the flight director over our wheels. I had a piece of steel all-thread as an axel but I don't think he saw that. He probably assumed I had a bolt into wood which would have failed. They only gave us 40 feet of run up. If we had the full 70 feet we probably would have gone a lot further.

Well at any rate, you had fun I hope. :) Well I never got a reply back from RB about the rules, but if you have the rulebook, that's that.. Besides, even if I was right about the rules in 2013, I guess I just didn't stop to think there may have been some changes. Never the less, my original query was meant as a "Oh did they get rid of that redonkulus rule of no testing before the flight. F ya!", and not a tone of being sassy. lol

rv7charlie (author)2017-10-01

On heat-activating the covering: Why not use a temperature calibrated iron, as is done when shrinking real aircraft fabric covering? Right temps all the time; no burn-through. And no more expensive than a heat gun.

mcghan (author)rv7charlie2017-10-02

Simply time. It's one thing to do a 3 square feet of a model airplane, entirely different to do 360 square feet. And iron is not practical and does not shrink the material up enough to yield the quality of a heat gun. Just turn down the temp of your heat gun and go slow, you won't burn any holes. It just took a while to learn the right settings, speed and technique.

rv7charlie (author)mcghan2017-10-02

I guess I missed the fact that you're shrinking the entire covering; I thought from the text that you were just activating the adhesive, so I assumed that over the ribs was what mattered.

Having said that, when covering a full size aircraft with dacron, an iron is *always* used to shrink the fabric, to maintain proper temperature control on the fabric. (Required to avoid under/over-tensioning.) On a roughly 5' x 15' wing, the heat shrinking with an iron takes an hour or two. Probably the least time consuming part of the covering process. (Just assisted in recovering the wings on a Kolb Twinstar.)

GreggH2 (author)rv7charlie2017-10-01

I use the same 1.5 and 3.0 doculam film he is using on my model aircraft. It is common practice to do exactly what you are describing to tac down the edges but when it comes to shrinking the material nothing does as well as a good heat gun. I'll attach a photo of my latest build in doculam. I paint mine because I am doing it as a flying semi-scale model but you get the idea I'm not just talking out of my butt. This is doculam with rustoleum paint added after shrinking. This plane was finished in August of 2013.

mcghan (author)GreggH22017-10-01

I agree, the Rustoleum paint sticks well. It's not as clean looking as colored Monokote but much cheaper. It's about $45 for 500 linear feet of 27" wide. The iron is critical for the seams, but for the open areas a heat gun is a must, just dial back the temperature and go slow, works great.

mcghan (author)rv7charlie2017-10-01

We had 4 irons going but they only do a about 3 1/2 at a time and it was VERY slow. Probably 40 hours of iron work alone to do 360 square feet of covering. You are more than welcome to try, but we found that a good temperature regulated heat gun is at least 10 times faster, you just have to be careful.

GreggH2 (author)2017-10-01

Great job. I've never been into FlugTag but I just might look into it now. :)

mcghan (author)GreggH22017-10-02

It was a lot of fun and motivated me to work on a project I had been thinking about for a long time.

vettebob (author)2017-10-01

I would DEFINITELY like to see more info on the use of this craft in a recreational aspect besides Flugtag. I imagine many prople would. Like towing it behind a boat and flying it just for fun. Or motorizing it with a small gasoline engine to fly around the country side as a ground effect plane.

Possible follow up info???

Thanks for sharing this fun project.

mcghan (author)vettebob2017-10-01

There will definately be followups. This was a very educational experience and showed me just what was possible with these materials and techniques. Right now I am starting in an electric powered version.

vettebob (author)mcghan2017-10-01

I'm a dedicated gearhead/engine guy. Also a pilot and an Ultralight aircraft instructor. There's a place down in Mexico I frequent thst has a huge, sheltered bay that is often dead flat. Also hundreds of square miles of flat sandy beaches at low tide. All PERECT for a ground effect airplane. I am very interested in this.

I was thinking something along the lines of one of the popular "Predator" line of gas engines available at quite good prices from Harbor Freight. No battery weight, recharging out in the oonies, etc....

I will be watching your progress with interest, and if I can help in any way, let me know. I design and build large scale R/C planes, and have built full scale ultralights and GA experimental planed. (Homebuilt Category)

Hey, here's a thought! Have a look at DLE and RCGF engines for Giant Scale R/C planes. For example, the DLE 120 twin makes 12 horsepower, generates 50 lbs. of thrust, and weighs only SIX pounds total. Two of those would be more thrust than my old 1982 full size ultralight plane had. I weigh 200 lbs., and I flew it at density altitudes of 7000 feet!

Vettebob

mcghan (author)vettebob2017-10-01

Thanks! I live on a 200 mile long lake so the plan was to build an aircraft that travels just 20' Off the water at 20 knots. In our tests, we were able to pull the plane to 20 knots with just 20 lbs of force on the tow line. A 10x36 prop connected direct drive to a 2HP 42cc Homelite chainsaw motor at 2200rpm would yield 14lbs of thrust at 20 knots. 2 of those would be 28lbs. I was thinking the same thing about using the predator engines as they are cheap, but they aren't light. I also have a PM2 paraplane and considered stealing the motors off that, or going full electric with build in solar panels. But I may check into your motors, I am considering entering the Boing GoFly contest and those might be perfect! My email is allen@keylinkit.com

KEUrban (author)2017-09-28

Where's a video?

mcghan (author)KEUrban2017-09-28

I'm working on making a complete build process video but it's going to take a while to compile several hundred hours of footage. You can see a lot of stuff on Facebook at @tnflugtag or tnflugtag.com

This was an early testing video: https://www.facebook.com/tnflugtag/videos/140558703197331/

The notorious lake crash:
https://www.youtube.com/watch?v=_Hx-dwXilTY&t=9s

Zipline Testing: https://www.youtube.com/watch?v=5b5VmThmSuE

Just our flight: https://www.facebook.com/tara.holancinhart/videos/10214275566030003/

The official RB video: https://www.youtube.com/watch?v=dppeL1F9oA4

Antzy Carmasaic (author)mcghan2017-10-01

Saw the Red Bull video. Went through all the other attempts which seemed like fun builds but not much in function. Then yours comes at the end(1:23 seconds) and boy that was waaay too good... Congrats on the win. You should put that video on the very first step.

mcghan (author)Antzy Carmasaic2017-10-01

I was trying not to make it a Red Bull promo. I have at least 7 different angles of the flight of varying quality as well as about 40 hours of build videos. I will be trimming it all down to a 5-10 minute video over the next few weeks as time permits. But I am already working on the next version of the plane with engines so I have been more focused on that.

gravityisweak (author)KEUrban2017-09-28

Exactly! This is way too insanely amazing not to contain a video! At the very least an animated GIF! Great job on this!

askjerry (author)2017-10-01

Clickable Links...

Flight

https://www.facebook.com/tara.holancinhart/videos/10214275566030003/

Official Video

https://www.youtube.com/watch?v=dppeL1F9oA4

Hint for others... type some text like ZIP LINE VIDEO then highlight that text... click on the link icon that pops up... and paste in your video link. Then you will have active links.

mcghan (author)askjerry2017-10-01

Thanks, I did that from my phone and couldn't figure out how to do links but I will do that.

Bazza00 (author)2017-10-01

I don't see that anyone mentioned that the 3M 3050 tape you mentioned is actually 3M 3350.