This is my take on this (I just finished building one myself, though I haven't yet tested it):twototwenty wrote:For the past month or so, I have been working on a chinook design and after several failed attempts the best I have gotten is ten seconds-the thing doesnt even reach the ceiling of the classroom i am testing in.
The main problem, besides the fact that is is spectacularly heavy(which I am working on), is that the rotors do not rotate at exactly the same speed, causing it to flutter in uncontolled spirals until it hits the ground...
Does anyone have any suggestions as to how I can make the rotors rotate equally? States is in a week, and although we have a fallback, I am getting worried.
1. Are your rotors almost identical? Generally, you probably want them to be as close to the same as possible, though depending on your design (eg. the rotors overlapping) this may result in the lower one spinning faster b/c air is already sped up by the top one, though I don't know if that would result in crazy spiralling.
2. Is the helicopter as a whole unbalanced? Making sure that the helicopter isn't more heavy on one side (axle) than the other might help with stability a little, though it won't solve the rotor speed problem.
3. Are your rubbers as close as possible to the same size (weight)? This is what probably affects rotor speed the most - try to measure the two rubbers as close to the same weight as you can.
If I missed anything/said something wrong, I'd like to hear any other advice anyone else has as well.
*EDIT: Okay, I definitely want to hear other perspectives, because I went and tried mine and it's doing the same thing. I won't say my exact times, but the wild see-sawing is definitely taking away time, especially since I don't have much clear space to test it - it keeps running into stuff and I don't want it to break.
BTW, how heavy is spectacularly heavy? I managed to get mine down to 4.72 g
though I don't yet know if it'll stand up to the strain of actually flying (I sure hope so...)
