My rubber band powered RC project is about to fly, or at least attempt ot fly. It is a Herr Engineering 35.5" cub kit covered with solite. All I need now is a battery for the receiver (GWS R-4P) and the 2 servos (FMA PS20). All together the current draw is 15.5 mA, that is with the servos not moving. With both servos moving as fast as I can move the sticks on my radio the current draw is between 200 and 280 mA. I was hoping that I could get away with using 2 coin cell lithium batteries to power everything but that didn't work. I found out that those batteries are designed for about 0.2 mA load, so even with out the servos moving that is quite a load. I did get 2 CR2032's to move one servo about 20 degrees very slowly before the voltage dropped too much to operate anything. So now I am looking for the lightest battery that will work. So far I have come up with 2 options, 4 AAAA cells at 6 grams each for a total of 24 grams or 2 CR2 lithium cells at 11 grams each for a total of
22 grams. Either should run the whole setup for several hours (depending on the servo usage of course). BTW an interesting tidbit for those crazy enough to try this, a 9V battery made up of 6 AAAA cells so you can take it apart and pull off 2 of the 6 and have 4 cells all soldered together with solder tabs for your power cord.I think I may need to get a full electric indoor flyer after this. I am looking for recommendations. I want something that will work the radio equip mentioned above and that will fly well indoors. I don't want an aerobatic ship just something to fly around in a gym, Preferably something with ailerons.
-- Chris W
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania