Rubber Band Airplane

For a school project I had to make an airplane. I decided to make a rubber band airplane based on a glider. The main goal of my airplane was to fly as far as possible.

Step 1: The Wings

One of the essentials of making a good airplane is the shape of the wings.

1. Decide how large your wings will be, I made mine 70 centimeter. Make a drawing seen from above how your wings will look like.
2. Make a drawing of your wing shape (section view). If your wings are rectangular you only have to make one drawing. In other cases two drawings will be needed (one of the the largest and one of the smallest section).
   Calculate how much layers of depron (3 or 5 mm) you need to use for building up the shape.
3. Combine the wing shape and your first drawing. Now you can determine the shape of each layer.
4. Make a drawing of each layer and control if everything matches. Notice that you don't have to make the complete shape because at the top and the base of your wings wooden parts will be added (the complete front with a 'D'-form and the end with a part of balsa wood cutted under an angle).
5. You also have to make three open areas in the wing: two in the largest section for putting the wings and the body together and one at the end for adding upstanding wing tops and balancing your airplane . The two holes in the largest section have to be as wide as the metallic battens.
6. Cut out your layers and glue them together.
7. Add your wooden parts to your wing ends
8. Add glue or tape all over the upside of the wing.
9. Take a large sheet of depron and bend it over the wing.

Make the middle part of the wings:

1. Use the drawing of your largest wing section.
2. Make the layers of the layering system.
3. Take two metal battens as wide as your slots and give both free ends a bend of 5 degrees upwards.
4. Glue the metal battens in the layering system.
5. Follow the same steps from above.

You can finish your wings by adding balsa wood at the end of each part. Don't forget the openings.

Making the wing ends

1. Take a part of balsa wood that just fits into the hole at the end of the wings.
2. Take a small sheet of metal and give it a bend.
3. Glue the two togethers
4. Make two balsa wood parts, one for the inside and one for the outside of the metal sheet.
5. Glue them together.

Now you can easily put everything together.

Step 2: the Tail

My tail is based on the tail of a glider.

1. Make a drawing of the horizontal and vertical plane.
2. Cut out the horizontal plane once and the vertical plane twice.
3. Create a T-profile by glueing to L-profiles together and paste it in the middle of the horizontal plane.
4. Take a U-profile (large enough to put the PVC pipe in) and paste the two vertical planes on it.
5. Paste the two vertical planes to the T-profile on the horizontal plane.
6. Use the same balsa slat as used in the wings and put it between the end of the vertical plane to get a closed ledge.
7. Make a part of foam that fits between the opening at the front. Make another part that is just big enough to cover the whole front.
8. Glue these two together and give the largest part a rounded shape.
9. Glue this part into the front of the tail.

Step 3: The Body + Propulsion System

The pvc pipe.

1. Take a pvc-pipe and give it a chosen length.
2. Drill holes in the pipe but only just upto the half of the length. I did this because the center of gravity of the hull is close to the tale. When you make holes the center of gravity will change.

The rubber band propulsion system.

1. Take a short piece of aluminium pipe with a diameter that just fits into the pvc pipe.
2. Drill two holes in the pipe, take the end of a rivet and press it into each hole.
3. Take the end of two plugs and make them fit into the pipe.
4. In the opening of the plug you can place the bearings.

5. Make an axis as long as you want but with a diameter of 3mm.

6. Shove the axis through the bearings

7. Use two clamping rings to keep the axis in its proper position.
8. Glue two clamping rings together. Fix the first one to the end of the axis. The second one holds the loop to which the elastics will be attached.
9. At the other end of the axis you can put the propeller together. The screw at the end fixes the propeller to the axis when the nose is added.
10. Take another short part of aluminium or pvc pipe with the same diameter of the large pvc tube. In this part you have to make two slots, this prevents that the bearing system doesn't turn around when the propeller is working.

Take a sleeve and put it on the pvc pipe, then add the part made in step 10.

Take 2 elastic ropes and attach them to the loop of the propulsion system. Pull them through the pvc-pipe and a washer, make a knot in the elastics when the right tension is reached to keep the propulsion system in its place.

Step 4: Assembly

Attaching the tail.

1. Take the tail and stick it to the end of the pvc pipe.
2. Drill two holes through the U-profile of the tailpart and the pvc tube and use rivets to keep the tail in its position.

Attaching the wings

1. Take two L-profiles and one U-profile and glue them together.
2. Stick this on the center part of the wings.
3. Take an U-profile and attach it on the PVC-pipe, make sure you have already found the center of gravity.
4. Attach the part made in step 2 on the U profile by using rivets and silicon glue.
5. Slide the left en right wing parts on the metal slats.

Step 5: Painting

You can choose your own color pattern but be carefull with the type of paint because some of them can corrode the foam.