RC Ornithopter for School Project

[Techno]

RC Ornithopter

Hello all, I was assigned a project earlier today concerning Leonardo da Vinci's Flying Machine. We basically have to build a flying machine according to Da Vinci's sketch and explain boring stuff like why it was invented. Meanwhile I decided to not just make one, but make it fly. To do this, I've spent a few hours on YouTube looking at other people's ornithopters and I've got an idea of what mine will be like. According to this video:https://www.youtube.com/watch?v=e3wWfKEdvpY It will use a crankshaft and connecting rods to move the wings. Unlike the video however, it will use a motor instead of a rubber band. The motor will not have a speed controller, I don't have a brushed ESC and I don't have a small enough brushless motor for the weight to be low enough. In addition, there will be a kill switch on the bottom so the motor doesn't keep running after landing. I will be using, plastic bags or whatever lightweight material to be the wings. In addition, the wings will be angled, a bit like a seagull (or an inverted Corsair) somewhere for better lift up than down. I also hope to make the wings cambered for efficiency. The dimensions are: Wingspan: 42" Length, 30". For control I have a 9V battery going to a UBEC with two outputs; one will be for the receiver/servos, and the other for the motor/potentiometer/kill switch. One problem is, how do I propel it? I could easily put a propeller on the crankshaft, but I'd rather manipulate the wings in some way especially since the motor will be doing low RPM. Also, the Servos are a little troublesome with the arrangement, the tail is like in this video https://www.youtube.com/watch?v=9W4OisoX2xo
As usual, suggest, and comment as you wish.

 

[rcspaceflight]

Two words: Continuous Servo.

Comment: Are you sure you want to make it that big? And are you sure you want it fully RC?

Instead of doing a full continuous servo hack, you could just alter the gears (remove the stopper) and then hook up a power source directly to the little brushed motor in the servo. It will slowly spin at one speed. If you use the right battery, the entire thing could be very light, so it could be much smaller. (And much easier to make.)

Here is an article I wrote on how I made a continuous servo for an "RC Car" I made: http://www.flitetest.com/articles/continuous-servo-hack

 

[roversgonemad]

There used to be someone making a rubber band powered ornithopter that even had a 3d bird body. 30 years ago my science teacher in high school had one. I have not seen one since however.... Do a google search for rubber powered ornithopter, there's quite a bit out there.

 

[Techno]

Two words: Continuous Servo.

Comment: Are you sure you want to make it that big? And are you sure you want it fully RC?

Instead of doing a full continuous servo hack, you could just alter the gears (remove the stopper) and then hook up a power source directly to the little brushed motor in the servo. It will slowly spin at one speed. If you use the right battery, the entire thing could be very light, so it could be much smaller. (And much easier to make.)

Here is an article I wrote on how I made a continuous servo for an "RC Car" I made: http://www.flitetest.com/articles/continuous-servo-hack

I would use a servo, but I have so many motors and other stuff laying around, I might as well use one of them. Also I'm not sure of a servo that can do the required 120 RPM because they're not usually spun continuously. I just tried to spin one laying around as fast as it could go on a servo tester, but it looked pretty slow compared to how fast it would need to go.