Experimenting with Dual Props on Single Motor

Here is a video showing some of my experiments with using two propellers on a single motor. My simple thrust meter uses a single prop to get about 750 grams of thrust, dual props at 0 degrees angle from each other resulted in 850 grams and dual props at 90 degrees from each other resulted in 900 grams of thrust.

Of course, using dual props results in greater current draw. But just throttled back and bit and got same flight times as single prop at full power, better flying stability in calm and windy conditions and more thrust on tap if I wanted it.

Could use a bigger prop or multiblade prop but was just interested in seeing how two propellers would play out. Now when I fly my P51 foamy I just leave both props on as there seems to be no downside.

I would like to try this on my wings but my current 3mm prop adapters are too short for two props - my P51 having a 4mm extra long adapter which had enough room for two props.

Since my P51 is a belly lander, I had to go with 0 degrees separation of the props (I tried 10 degrees separation and it broke the props on landing). I plan to get my P51 that has landing gear flying again and will try the 90 degrees separation.

RC Dual Propeller Experiment (3 min 13 sec)