Syma RC helicopter papercraft body?

[Paragon]

Hey! So I usually inhabit the papercraft side of the forums here, but a little while back I bought three of those micro Syma RC helicopters, and have been having a lot of fun with them, since they're very easy to fly. I got thinking about combining the two hobbies though, since I was a little disappointed nobody seems to offer a Mil-24 Hind RC helicopter, and was wondering if anyone had any advice about that kind of endeavor.

I know a few things: I'll obviously have to re-scale whichever kit I built to fit the small frame of the RC helicopter, and I'll probably need to weigh the body after building to make sure it's not too heavy, but there are things I could use help with.

I assume building the paper body lighter than the original plastic one will make for longer flight times at lower throttle, but I could also imagine it causing the aircraft to be less stable.

Since I'm going with a real helicopter design, I assume I don't have to worry about aerodynamics too much, but are there things I should keep a lookout for?

What kind of concerns should I have for the helicopter's center of gravity and center of mass? I imagine I should try to keep the main shaft directly above it, right? It shouldn't be a problem to keep the main rotor located where the Mil-24 has it's rotor already, should it?


The Syma mini-helicopters only have controls for pitch and roll, no yaw, so they use smaller vertical propellers on the tail for pitch and forward-backward movement. I noticed all three of my helicopters perform differently, and that all three have somewhat different tail rotor placements that seem to be dictated by the design of the real helicopter they mimic, and I assume this has a large impact on performance. What do I need to know about this placement if I want faster forward movement?

And of course, if anyone else around here has done this kind of thing before, it'd be great to hear some advice.

 

[zathros]

The propeller in the back controls pitch. The left and right movement is "Yaw". The helicopters have no "Roll" , "Collective", or "Cyclic" controls. If you pitch forward, you get forward speed, but you lose life as the blades are no longer parallel to the ground. Any temporary gain in height is due to more rpm's being put into the main rotor, thus lifting the helicopter. In a real helicopter, the blades would spin at a high r.p.m., the "cyclic" would give all the blades more pitch from the "collective" input, to lift the Helicopter. Any loss in rpm from this would be offset by throttle input from the pilot.

The simple R/C helos, I have one too, they are fun, are very easy to fly. However, without the ability to roll, which is done through the cyclic (the cyclic controls the pitch of each blade individually), it is sometimes impossible to land in trick places because of lack of cyclic control. If you alter the amount of lift from the rear rotor, you will alter the speed in which the helo pitches forwards or backwards. One way to experiment with this is ust to add some normal plastic tape to the end, making sure that you use the same amount, so they stay balanced, and that will allow you to trim it the way you want. You could also try making light weight wings, thing, and at very high angles of incident, so that when you move forward, the are still pointing up a little, and give you lift. I would not alter the main rotor blades as this will just tax the helicopter, decreasing battery life, balancing them would be very hard. I think it would be very difficult to get any appreciable gain in performance. You could always play with one though. Adding winglet tips that point downwards may prevent air from leaving the bottom and going over the top, increasing efficiency. I believe anything you gain in one flight characteristic will change another so all bets are off. If you do experiment, please post your results. I would also recommend making the bodies out of the thinnest paper you can use (normal, weight paper, not card stock) and reinforce the location points with thins strips of cardboard, like a skeleton. It will probably weigh less than the original that way. Good luck! .