Rubber

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Re: Rubber

Post by chalker7 » April 25th, 2011, 2:56 pm

mrsteven wrote:So the torque meter is just so you can measure how much torque gives you the best flight and decrease/increase winds to get that torque number? So youre not really measuring the number of winds, but how much torque is on it before flying.

Like instead of saying 20 winds is the best flight (for example purposes) you say X torque is ideal?
Torque is not a substitution for counting winds. It is just another data point that supplements the other information about any one flight. Really, the more useful data/notes you have recorded for every flight, the more you should be able to maximize your times by adjusting variables.

For example, the best indoor fliers record (at minimum), just in relation to the motor, the rubber band size (either width or mass/length), batch of rubber, how many times each rubber band has been used, winds to max, max torque, number of winds backed off, turns left at landing and other general notes (possibly temperature, etc). And that's not even getting into notes about the airplane itself or the flight, both of which involve a huge number of data points. If nothing else, I'd say the best indoor freeflight competitors are some of the best note-takers and detail oriented people I've ever met.
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Re: Rubber

Post by mrsteven » April 25th, 2011, 3:09 pm

Ok, but given that 40 winds with 40 torque produces 2:00 of flight, then 40 winds with 30 torque produces 1:30 of flight, Would you follow the winds or torque?

Or even switch it, so the winds decrease to keep the same torque, which in your opinion is better to keep consistant while flying? Torque or winds

So measure the success of a rubber width/batch based on torque or winds? Which would produce a more controled and constant data set
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Re: Rubber

Post by sj » April 25th, 2011, 3:15 pm

Thats not really the way torque works. Its a three-way relation between torque winds and time. So winds dictates how many turns the rotor can turn and therefore the max time the rotor can turn. Then Torque is what causes the helicopter to climb or descend. there is a torque below which the heli cannot climb. this is were the decent starts after that regardless of winds the heli will come down. Thus for max time u want rubber that can have the most winds above the torque required to produce sufficient lift to climb.
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Re: Rubber

Post by mrsteven » April 25th, 2011, 3:23 pm

Ok, but when winding the helicopter with the goal of flying which is better to follow to use as the gauge of when to stop winding (thats my question, I guess I didnt articulate that well). Like right now I stop winding at X number of winds, do you stop at number of winds or at a certain torque according to meter?
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Re: Rubber

Post by chalker7 » April 25th, 2011, 3:24 pm

mrsteven wrote:Ok, but given that 40 winds with 40 torque produces 2:00 of flight, then 40 winds with 30 torque produces 1:30 of flight, Would you follow the winds or torque?

Or even switch it, so the winds decrease to keep the same torque, which in your opinion is better to keep consistant while flying? Torque or winds

So measure the success of a rubber width/batch based on torque or winds? Which would produce a more controled and constant data set
You're looking at this the wrong way, neither torque nor winds are important to keep constant or change. The only data point that fundamentally matters is the flight time, all you should be doing is attempting to maximize that. If changing one variable drops the time, think about why it did that and adjust the variable accordingly. Did the helicopter land with most of its winds? Then you probably should increase the size/width of the motor (thereby decreasing winds and increasing torque). Did it deadstick (run out of turns midflight)? Then you should probably do the opposite (decrease motor size for more winds and less torque). This is a really complicated system that varies for every helicopter. Really, the only thing you can do is fly your helicopters a lot and learn about their behavior first hand.

And I would measure the success of a motor based on the flight time I can achieve with it. There are some ways to predict motor performance with bench-top tests, but you really need to understand how the different variables will affect the flight before you get into that.
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Re: Rubber

Post by chalker7 » April 25th, 2011, 3:26 pm

mrsteven wrote:Ok, but when winding the helicopter with the goal of flying which is better to follow to use as the gauge of when to stop winding (thats my question, I guess I didnt articulate that well). Like right now I stop winding at X number of winds, do you stop at number of winds or at a certain torque according to meter?
Oh, well in that case I'd usually rely on the torque meter. It's easier to tell that the rubber band is about to break this way because you start to see the torque spike up.
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Re: Rubber

Post by mrsteven » April 25th, 2011, 3:30 pm

chalker7 wrote:
mrsteven wrote:Ok, but when winding the helicopter with the goal of flying which is better to follow to use as the gauge of when to stop winding (thats my question, I guess I didnt articulate that well). Like right now I stop winding at X number of winds, do you stop at number of winds or at a certain torque according to meter?
Oh, well in that case I'd usually rely on the torque meter. It's easier to tell that the rubber band is about to break this way because you start to see the torque spike up.
ah ok. thanks!
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Re: Rubber

Post by illusionist » April 26th, 2011, 5:07 pm

Has anyone had luck with cutting 3/16 rubber by hand with a scissor? As you can tell, I'm kinda desperate, and I don't have time to order more rubber. I want something along the lines of 5/32.
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Re: Rubber

Post by sj » April 26th, 2011, 5:18 pm

I don't think that would be precise enough. Irregularities in the thickness of the rubber may lead to premature failure. Perhaps clamp it down under a straight edge and use a razor knife?

Also would it make sense to use slightly thinner rubber for our helicopter because it is almost landing dead stick on a 25 foot ceiling so it will definitely go dead stick on the ceiling at nats. So i am thinking slightly thinner rubber will allow it to land just before it dead sticks. Is this correct?
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Re: Rubber

Post by mrsteven » April 26th, 2011, 6:24 pm

sj wrote:I don't think that would be precise enough. Irregularities in the thickness of the rubber may lead to premature failure. Perhaps clamp it down under a straight edge and use a razor knife?

Also would it make sense to use slightly thinner rubber for our helicopter because it is almost landing dead stick on a 25 foot ceiling so it will definitely go dead stick on the ceiling at nats. So i am thinking slightly thinner rubber will allow it to land just before it dead sticks. Is this correct?
I would agree with that
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