Design: Trimming a paper model aeroplane

You would usually trim a paper model aeroplane by trial and error, but if you do it by calculation you’ll also develop your engineers’ eyes.

This video explains the problem and shows you how to find the ballast weight the paper glider needs on its nose if it is to fly well. In the end you will specify the required mass.

To get a clearer idea of the task:

1. Download and print out the design specification with the plans of the model plane.
2. Download the table (this will help you with the calculations).
3. Download and read the Paper Aeroplane Story.
4. Make the aeroplane!

If you just watch the video it will take about 6 minutes. If you do the calculations it will take longer; how much longer depends on many factors, but allow a total of 30 minutes. It will take longer still if you make the paper glider, but what price fun?

If you are stuck (or even if you aren’t) you might like to look at the worked solution that is available from the Downloads section.

Talking points

• Note from RF. I had hoped that my paper glider would perform better than the classic folded paper aeroplane. It didn’t seem to work out that way. But I’m still trying. Do you have any comments on this?
• We’d like you know whether you built the paper glider, and if so, did you find the right ballast weight by trial and error, or by calculation? What was your experience?’
• It’s been suggested that you could weigh the ballast weight, drinking straw and paper components using the cardboard balance from Week 3. You could cut out pieces of paper as your weights (an A4 sheet of 80 grams per square metre (gsm) weighs approximately 5 grams). What do you think of this suggestion?

If you attempt the design task, take a photo and upload it to our Through Engineers’ Eyes Padlet wall. You can include a link to your photo in the comments for this step (click on your post on the Padlet wall and then copy the web address).