Height of flight

[ericbro]

Has anyone figured out if there's a way to limit the height of your flight while maximizing duration? Our state competition will be in a gymnasium with lattice-like ceiling supports, and I'll like to be sure to stay below it.

[thewinner]

I doubt it. However, I read the rules from some other state (NC, I think) and they allowed you to tether your helicopter a set distance from the ground. But, I still don't think that would be a good idea, since the tether would just be more dead weight for your helicopter to lift.

[illusionist]

I agree, but then I think it should also be allowed to count the tether as part of the total mass of the helicopter. If you used something like sewing thread, it wouldn't add an excessive amount of weight. It would be nice to be able to do that.

[thewinner]

According to those rules, the tether unfortunately did not count as part of the weight of the helicopter. But I wish it was, since many people's helicopters are underweight anyway.

[4science]

Wouldn't a tether be against the rules? 3.m. says the competitor may not steer the flight-- a tether would steer away from a certain height. Also, it is "free flight". Perhaps a tether could be added to next year's rules?

[illusionist]

Right, it should be added as an option to use a tether in next year's rules.

[nmantz9]

How many feet in the air does the helicopter have to pull me?

[thewinner]

...I'll assume that was a joke.

[new horizon]

I'm sorry if this is late, but it seems everyone is advocating a tether because it's difficult to control altitude. It is not, management of the torque on the rubber by dewinding and trimming allowed us to control the altitude of our flights at regionals where the girders were very unforgiving. Sure you can argue that it is difficult to do accurately, but if you leave yourself enough margin for error it works fine. At regionals there was a team that marked out the altitude of the flight in relation to torque, props to them going way beyond every other team and doing that.

[chalker7]

How long of a flight did you have? In particular, how long did you hover for? The issue that a lot of teams are having is that their helicopters seem to have two modes - climb and descent. The torque window is pretty narrow for the middle, cruise/hover mode.
Would you care to share any details on your specific design? I personally suspect narrow rotor blades with low pitch might make hovering easier, as the "torque window" for those would be lower thus allowing you to use thinner motors that have a more shallow torque curve profile during unwinding. I haven't built enough to test this out, but the helicopters that I have seen hover well seem to follow that trend.