My Background on Capacitor Powered Free Flight Airplanes
When the first PowerUp unit came out for free flying paper
airplanes I thought this something I just had to try. In the past I have bought
or built various free flight model airplanes powered by a capacitor and found
the thought of getting it to perform just a little bit better very fun. For
whatever reason I did not order the first version but when the PowerUp 3.0 for
radio control became available I ordered one of each.
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| PowerUp 2.0 Capacitor Paper Airplane |
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| PowerUp 3.0 RC Unit |
My first capacitor airplane was sold in toy stores by Estes,
it was light, small, and flew fairly well. After buying another one, I put the
power unit from the first one on a very light balsa and tissue covered
airplane. It flew a couple of circles indoors and then there was too little
power left to stay airborne.
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| Estes Capacitor |
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| Balsa Airplane Using Estes Components |
After this I purchased another capacitor airplane at a toy
store that had a gear drive spinning a larger propeller, it was fairly heavy
but the power was pretty good. Stability of the little yellows low wing foam
plane wasn’t the best, with some tweaking I did get some fairly good flights.
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| My Wright Capacitor Design |
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| Student Designed Capacitor Airplane |
My next experience with capacitor powered airplanes was to
design a balsa and tissue airplane that conformed to the rules for the Wright
Capacitor Science Olympiad event. With a working airplane I was able to coach a
student my email so she could create her own airplanes for competition, see my
blog post about this.
Observations of the PowerUp 2.0 Unit
On my scale the entire PowerUp 2.0 unit weighed about 6.3
grams. The weight is distributed with the heaviest component the capacitor and
plastic clip on front and the electric motor and propeller at the other end. It
is not possible the change the distance between the two components because of
the mounting on a carbon rod.
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| PowerUp 2.0 Components |
In designing an airplane normally the nose is shorter and
carries more weight and the tail needs to be as light as possible to balance.
Paper airplanes tend to be a delta type of wing with more lifting area to the
rear which should be better with the weight of the motor in the rear. From the ideas I have seen of other foam plane designs for PowerUp,
twin booms are used so the motor/propeller can be slightly forward of the tail
surfaces without interfering with the propeller. That is what I plan to try
next.
Without making any thrust measurements and from what I have
seen, the amount of thrust produced by the tiny propeller on direct drive
appears to be minimal. For comparison just feel the air movement behind the
propeller and feel the air behind a 6” diameter propeller spun by a loop of
rubber, no doubt more thrust from the rubber power source. Therefore the
airplane will need to be light, produce a fair amount of lift yet not create
too much drag.
Paper Airplane Attempts
After receiving the PowerUp units I folded the paper
airplane design given in the instructions with the 2.0 airplane. After much
tweaking of the paper tabs I never was able to get a flight much longer than 35
feet. It appeared that as the airplane was starting to show signs of level
flight the paper would bend and the plane would spiral into the ground.
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| PowerUp 2.0 Added to Foam RTF Glider |
Using the Foam Airplanes I Had
My original intent was to put the unit in a foam model
airplane so I started trying to put the PowerUp on some the foam airplanes I
already had. First was a ready-to-fly foam glider that appeared to be about the
right size and felt fairly light. I bent some paperclips to attach the unit on
top, it would extend the glide slightly but never would climb. After that I found a canard glider I built
from foam plates and a plastic straw, not enough wing area, same for a similar constructed
glider but this required nose weight to balance.
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| PowerUp 2.0 on Canard Foam Glider |
Next Steps
At this point I am searching the Internet to see what other
people have done for better success. There is a guy on YouTube known as
GrandDadisAnOldMan that had a couple of videos on a twin-boom airplane built
from foam plates that with some adjustments he got to fly rather well, I am
going to attempt a similar airplane. I
also found a video of someone that had built a better paper airplane with
larger wing area that flew pretty well. This has motivated me to try building
from paper again also. If I can achieve some success with the free flight
capacitor unit I will attempt experiments with the PowerUp 3.0 radio control
unit.
So much fun experimenting with this, I hope to hear from
other people working with this.
Update:
I tried another paper airplane design and put new batteries in the charger. This plane flew better than previous design but still would not climb, only flew level.
Bill Kuhl
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