SweetDreams - a Dream Themed Aircraft for Flugtag

SweetDreams is a dream themed home-made aircraft which was built for the 4th Redbull Flugtag in Istanbul. The plane was designed to generate high lift at low speeds but failed due to a small accident on the ramp. I decided to share our experience & build in detail to encourage you to build your own plane!

Outline
In the first step, I will give you a little bit of history of Redbull Flugtag. Next, I will explain the Idea behind this project. Then I will give you an insight into the design process of this plane, so you'll be able to design your own plane. After giving you a step by step assembly guide and show you how to test your plane, I'll end the instructable with a troubleshooting guide. So, if you encounter any problems during your build you can solve them easily. The purpose of this instructable is not just to give you a cookbook. I'll show you the way I built this project and provide you with open-ended questions, so you can add your own ideas, and take this project even further. I strongly encourage you to share your build when it's done!

Let's get started.

Red Bull Flugtag (flight day in German) is an event where 40 teams build and design flying machines where the wingspan is limited by 6 meters and the length by 8 meters. The flying machines are launched off a pier about 7-9 meters high in to the sea. Before launching their aircraft each team is given around 30 seconds on the pier to perform an act.[1]

Teams are judged on three criteria:

• Flight distance
• Creativity
• showmanship

Note: The rules of the event can change from city to city. These rules were written for the 4th Istanbul Redbull Flugtag. Check your local event page for details.

[1]https://www.redbull.com/ucusgunu

After I heard that Flugtag was coming to my town, I contacted some friends which I knew would be as excited as I am. They were all from different backgrounds which made the building process much more enjoyable. Everyone learned new things from each other!

After a long brainstorming session, we decided to create a dream themed aircraft. The idea was to create a 2-part airplane, where the first part was a carriage shaped like a bed to carry the plane, which would fall after it was pushed off the pier.

We created a sketch of the idea and submitted it for our application.

There are no limits for the theme of your aircraft. use your imagination!

Plane

Wood (15 x 20 x 3000mm ) x 4

Wood (15 x 20 x 2000mm ) x 4

Wood (45 x 25 x 3000mm ) x 4

Wood (45 x 25 x 2000mm) x 1

Foam (30mm) x 6

18m^2 covering foil

Wood screw (10mm) x 100

Steel nut & bolt (14mm x 50mm) x 16

3D Printed and Laser cut pieces (see step 9)

Base(bed)

Wood (50 x 40 x 1700mm) x 5

Wood (50 x 40 x 2000mm) x 4

Wood (50 x 40 x 1200mm) x 4

50mm diameter wheels x 4

Wood screw (60mm) x 48

Bedsheets and pillows

Tools

Gorilla glue

PVA Wood glue

Drill

Cutting knife

The airfoil of this aircraft is NACA 2415. This airfoil was chosen because it can generate large lift in slow speeds, which is what we needed. The overall structure of the plane was created in xflr5 to analyze lift data and make adjustments accordingly. If you are new to xflr5 you can find more info here:

I imported the airfoil structure into Fusion 360 to design the base and wing structure of the plane. This part is crucial if you want to create and build a scaled-down version of your plane to test it. Also, it gives you a detailed technical picture.

Safety First

The safety of the pilot should be your number one priority while designing the plane. We designed the part where the pilot is carried such that an impact would not cause any harm to the pilot.

We created 4 characters for our performance

• Pilot with nightdress
• Prince
• Princess
• Witch

We printed the airfoil on a large piece of paper and cut along the lines to create a template, later we used this template to trace the lines on to the foam.

At first, we used a razor blade to cut the foam but it got harder with time. So we decided to use a jigsaw instead. I recommend to clean up after each cut because the foam dust gets everywhere.

3D printing

Note: You can find the 3d files attached to this step.

48 pieces of L shaped parts has been used to strenghten the connection between the wood and the foam.

The printer I used is the TEVO Tornado with the following settings:

• Nozzle: 0.4mm
• infill: %20
• Filament: PLA

Laser Cutting

the most important part of the plane is the junction between the two wings. This junction has to be strong enough to carry around 70-80kg's. we decided to laser cut metal to connect these two pieces with 14mm steel bolts.

For this part you'll need:

• Airfoils that you've cut in step 8
• Wood (15 x 20 x 3000mm) x 4
• Wood (15 x 20 x 2000mm) x 4
• Wood (45 x 25 x 3000mm) x 4
• Foam (30mm) x 6
• Clamps
• Gorilla glue
• Patience

First the airfoils were positioned on the wood as shown on the picture. After measuring and making sure they were all 50cm apart from each other, gorilla glue has been used to connected the L shaped 3d printed parts to the wood & foam. this process was repeated for each airfoil.

Note: After gluing each part you should use a clamp to secure it. This is a curicial part since gorilla glue can expand up to 4 times while setting.

The covering film that we've used is some cheap nylon that we found on Bauhaus. We stretched and used staplers to attach the nylon to the wood. I do not recommend this option since this nylon is fragile. We had no choice to use another option because we did not have much time and budget.

In this step you'll need:

• wood (50 x 40 x 500mm) x 2
• wood (50 x 40 x 720mm) x 2
• Pipe foam
• Laser-cut carrier piece
• 14mm bolt and nuts x4
• Drill & 14mm drill bit

In this part you'll need:

• wood (50 x 40 x 1700mm) x 5
• wood (50 x 40 x 2000mm) x 4
• wood (50 x 40 x 1200mm) x 4
• 50mm diameter wheels x 4
• wood screw (60mm) x 48
• bedsheets and pillows
• wood glue

We carefully placed the wings on the back of the truck and tied them tightly in to place so they would not move.

After we got the plane out of the truck we realized that the covering film on the plane was torn apart. Lucky we brought some backup covering film, we re-covered the tail of the plane with duct tape. The pillows and sheets were attached using a stapler to the bed. Also, some details such as the stars on the plane were cut and pasted on the plane.

- The covering film is damaged

Go and grab some duct tape!

- I accidently broke the foam

Well mistakes happen, you can change the foam by just cutting the damaged part end replacing it. bring some extra foam with you.

-The glue is not holding the wood/foam

There are special glues for special materials try a different glue according to the material you use.

Our plane was blown over on the ground by a strong wind and the tailpiece was broken before we even could go off the pier. But we decided to jump anyways. If you watch the video you'll see the broken piece on the plane. Accidents happen and you can't be prepared for everything. So even though our plane failed, in the end, we had a lot of fun building, traveling and dancing/performing together!