Duration

[chia]

So our JV team is having trouble and i thought i'd act as some correspondence. I couldn't solve their problems or help them out myself, so of course this is where i turned

They managed to get the copter flying - it gets up to the ceiling (we were testing in the school hallway for this), floats for 10 seconds, and starts falling. I see the rotors hitting the ceiling a lot as they reach the ceiling - is this why it falls so soon?

Btw, specs on the copter:

1/8 rubber, full 2 grams is utilize of course
Copter is 4.13 grams
I won't indulge on the rotor design, but i will say it's fairly decent, and they are well balanced
It's the typically fixed rotor at bottom, free rotor at top design
Yep, that's about all i can think of. Thanks for any help!

Does their copter have a ceiling bumper thing? (my copter wobbled and they hit the ceiling anyway, but that was because it was really unbalanced.)

[Mr. Cool]

So our JV team is having trouble and i thought i'd act as some correspondence. I couldn't solve their problems or help them out myself, so of course this is where i turned

They managed to get the copter flying - it gets up to the ceiling (we were testing in the school hallway for this), floats for 10 seconds, and starts falling. I see the rotors hitting the ceiling a lot as they reach the ceiling - is this why it falls so soon?

Btw, specs on the copter:

1/8 rubber, full 2 grams is utilize of course
Copter is 4.13 grams
I won't indulge on the rotor design, but i will say it's fairly decent, and they are well balanced
It's the typically fixed rotor at bottom, free rotor at top design
Yep, that's about all i can think of. Thanks for any help!

Add a point to the end of it so the point hits on the ceiling and the rotor is free to turn.

[jander14indoor]

Are you using all two grams of rubber? Winding the heck out of it? You need to do that to get a long flight. Is the rubber thick enough or are you only climbing on the high end of wind torque?

Plus that ceiling bumper really helps if everything is balanced. Good copters look like they've just stuck to the ceiling, but are still spinning.

Jeff Anderson
Livonia, MI

[lllazar]

Hmm, we worked with them again today and we attached the probe, but it still can't seem to stay at max height for longer than 10~ seconds.

Btw, we are winding the rubber well, around 750 winds which is the usual, and also what we've been doing on our varsity copter. The copter is pretty wobbly though. I never had issues with balance too much on mine because i tended to try and built it all with care, how would you suggest they balance the rotors?

[smartkid222]

I think it may need more winds (combined with a higher ceiling or a ceiling bumper).

[lllazar]

Again, they get the usual 750 winds (.125 rubber). Does how fast you get the winds in matter?

[_HenryHscioly_]

I've had the problme that the person, holding the rubber badn at the end to stop the rotor from spinning, fingers hurt quite a bit.
I am usually the person winding it, so I didn't relaly know, but when my partner did the winding, and i held the rubber, i noticed how much it hurt.
When my partner wound faster, it seemed like it hurt less, and winding finished a lot quicker.

I always thought that winding it slower might result in better results..but I have no idea why I thought like that.
Now, I usually just try to wind faster.

Does anyone have a suggestion in winding so that it wont hurt at all?


Has anyone's lower rotor hook ever broken?
During my last session of testing, the hook was bending A LOT, and so my partner and i tried to quickly fly our helicopter to releave the stress, but the top rotor ended up braeking apart instead...The metal wire going through the upper rotor separated, and all the wounds ended up spinning the metal, and my index finger and thumb got cut, it was deep tooo.(can't play my beloved instruments for a long while now) :'(
Has anyone had similar problems? or was my metal wire just not glued well enough into the rotor?
How can i fix the rear hook problem? if the top didn't break, the bottom probably would have..

thanks for any advice!

[jander14indoor]

How are you winding, shouldn't hurt either person! Are you actually holding the end of the rubber? Don't, hook it on your copter on the fixed end or on a stooge (heavy piece of wire anchored to something heavy with a hook the O-ring on the motor slips over).

Winding slow is supposed to be better, gives the rubber time to cool and allows more energy storage, probably only a few percent improvement, not important until you have the basics right.

I've never seen a wire hook break, but I've seen them bend open, if that's the problem, go up a size or two on your wire. If you are using one of those plastic Ikara hooks, replace it with wire, 0.020 to 0.025 should work, with the fatter motors I'd start with maybe 0.025 inch wire.

Prop shafts do sometimes break away from the rotor, as you found DON'T try to stop them, it will slice your fingers something fierce as you unfortunately found out. In addition to gluing the wire to the rotor, do you hook it over the end so it is mechanically retained too? When winding or launching, try not to hold the rotor near the hook, but to one side.

Jeff Anderson
Livonia, MI

[_HenryHscioly_]

Oh, ok.
We had one end of the rubber band already on the free-moving rotor, and a person held the wire hook and the rubber band on it at the same time, because when we tried to only hold the rubber band, winds kept escaping becuz we couldn't hold it tight enough.
Our lower hook that's anchored to the motorstick was a plastic one, I'll use wire to make the hook on my new helicopter.
I do bend the wire to hook over the rotor for it to be mechanically retained, I'll try to make the bent over part a little longer next time and use a litttle bit more glue.
Thanks!!

[donlayola]

I am using the design on Freedom Flight Models(Parlor Copter on TurnerToys). I tried using 1.97 grams of 1/8 rubber. I used about 750 winds using sil-slick lubricant from TurnerToys. The copter only went for 1:06. 3/16 rubber with 500 winds gets 1:42, but 3/16 rubber can only get so many winds.I thinks the biggest problem is that there are so many winds left in the rubber band when the helicopter hits the ground. When it is on the ceiling, it is perfectly verticalr. As the helicopter begins to descend, it starts to wobble and go in circles. I don't know how to increase the efficiency, because the prop hangar already spins smoothly on the music wire. There is probably about 400 winds left in the rubber band when the helicopter hits the ground. Does the wobbling lower the time that much? I used Japanese Tissue instead of mylar, but still had to add .5 grams of clay to the bottom the meet minimum weight. How can i increase efficiency?Why are there so many winds left at the end?
Thank you very much.