Small Rubber Band Powered Plane

Disclaimer: This is not an easy plane to build, and I didn’t get it fully working. Use this as inspiration only or as a basis for a new design

This is a small rubber band powered airplane that uses very little filament and can be printed in slightly more than an hour. It is partly made of paper and barbecue skewer to keep things light. The propeller allows you to use a cordless drill to wind up the plane. 

Parts needed for this plane: 

• Printed parts
• A4 sized sheet of paper
• Three barbecue skewers 
• Small piece of PTFE Bowden tube
• Rubber band(s)
• Glue

Assembly: 

• print all the parts
• If the holes are too small, enlarge them with a 3 mm drill. If they are too loose, you and use a small amount of glue to keep everything in place. 
• Wings: 
  • Cut a strip of paper to be about 10 cm wide 
  • Unclip the top of the of the printed wing mounting part in the front
  • Align the center of the paper with the mounting part and close the front again, clamping the paper in place and giving it a curve
• Tail:
  • 
  • Cut out the tail according to the drawing
  • Bend the control surfaces about two centimeters away from the back edge of the paper
  • Bend the tail paper in the middle 
  • Put a few drops of glue along the center and place the barbecue skewer on them
  • Bend the paper so the control surfaces meet at a 90° angle
• Propeller:
  • Heat up one of the small thin sections next to the center of the propeller by holding it a few centimeters above a candle flame for a few seconds 
  • Rotate the propeller blade slightly
  • heat up and rotate one prop blade at a time 
  • make sure to rotate both blades an equal amount in respect to the center hub of the propeller
  • Make sure to keep the propeller blades pointing straight away from the center
  • If you are not happy with the results, you can always heat up the prop again and reshape it. Forming the prop is not as hard as it may sound
• Put the tail through the back of the wing and in the back of the middle connector
• Push two skewers in the nose and put them in the middle connector through the front of the wings
• Cut the PTFE tube to about 16 mm. Make sure to cut it of straight and place it in the front of the nose
• Slide the hook through the PTFE Tube and push it into the propeller. If it’s too tight, make the hook thinner using a box cutter or sharp blade. If it’s too loose you can put a small dab of glue on the front of a propeller 
• You can use one large or several small rubber bands. You can secure them in the middle connector using a short piece of barbecue skewer. The rubber band should not be tight. It should only get tight after being partly wound up 
• Throw the plane onto a soft surface and adjust the tail until the plane glides gently 
• Now you can wind up the plane using a cordless drill, release it and watch it fly! 

Design considerations:

Wing: 

The wings are made of paper to keep them light and simple. The paper is bent to make it stiff and form an under-cambered airfoil. The wings are just the length of a A4 sized piece of paper, so you can print all kinds of patterns on it. You can also use a larger piece of paper or glue two sheets together to increase the wing area. The printed part in the center of the wings also keeps the paper in shape and gives it a little bit of dihedral. 

Tail: 

I experimented with a fully 3d printed and a partly 3d printed tail. Unfortunately, both where too heavy and made it impossible to get the center of gravity of the plane in the right position. So I decided to go with a simple V-Tail design made form paper. The barbecue skewer also helps keep both halves of the tail at a 90° angle to each other. 

Nose: 

The nose uses a short piece of PTFE tube as a bushing to reduce friction for the propeller.