Efficient Propeller Design Question

[deleted-376138]

Hi,
I am planning on performing this experiment using the suggested propellers. Do you have any tips on how to trim the propellers and any suggestions on the chord lengths I should trim them to?
Thank you,
JL250

[norman40]

Hi JL250,

I’m assuming that you’re working on the project described here:

https://www.sciencebuddies.org/science- ... p018.shtml

The propellers suggested for this experiment are shown here:

http://www.freedomflightmodels.com/paypal.htm

I haven’t worked through this project but it appears from the above link that the propellers are made of a hard plastic. If so, you might try using a file or sandpaper to trim them.

The chord length of the suggested propeller is about 35 mm. You might try trimming down to 31 mm, 27 mm and 24 mm for the three other chord lengths needed for the experiment. Trim equal amounts of material from each edge of the propeller.

I hope this helps and good luck with your project. Please post again if you have more questions.

A. Norman

[deleted-376138]

Thanks for the reply. I have one more question:
How would I measure the chord length, and where on the propeller blade would I measure it?
Thanks for your help,
JL250

[norman40]

Hi JL250,

The chord length is the width across the propeller blade. You should measure the chord length at the widest part of the propeller blade.

The chord length of the propeller recommended for this project is about 35 mm (or 1-3/8 inches). You might try using a ruler to measure the width of the blade and check to see if you get the 35 mm specified width. If the propeller blade is too curved to use a straight-edge ruler, you might try using a tape measure.

I hope this helps. Please post again if you have more questions.

A. Norman