Duration

[wlsguy]

.... It is entirely possible to build a 3.5g helicopter with just hobby shop balsa wood and (light) tissue paper. It's all in the wood selection and careful construction techniques.

Good advice.

Our helicopters last year were all less than 3.5 grams with larger rotors and solid motorsticks. We actually had to add weight to bring them up to 4.0g. The only specialized material we used was film covering rather than tissue paper. We have carbon fiber available but it really is more trouble than it's worth.

Also, since this is the duration thread, has anyone tried their helicopter this year (with 3.5g and unlimited motor size)? What kids of times are you getting?

[lucwilder42]

I haven't begun experimenting yet, but I'm curious to find out how the unlimited rubber thing will work out. It's yet another variable we have to balance; winds vs. mass. Each copter will enforce its own rubber mass limit

[chalker7]

I haven't begun experimenting yet, but I'm curious to find out how the unlimited rubber thing will work out. It's yet another variable we have to balance; winds vs. mass. Each copter will enforce its own rubber mass limit

Yep, in fact I'm not entirely convinced carrying 2 grams last year was ideal. I heard rumors of teams doing quite well with 1.5g or less (with the specific intention of cutting mass and unused winds).

[jarrred_1415]

4 minute flight

[sciencegreek]

Is that time with a helicopter with this year's specs???

[chalker7]

Is that time with a helicopter with this year's specs???

I would not be surprised by a handful of teams going over 4 minutes this year (either with or without the bonus)

[purplepenguin]

I wasn't sure where to post it, but I have some questions about the flight log requirements.

Firstly, when they say motor size, what exactly are you supposed to measure?

Also, how do you measure torque?

Thanks so much to anyone who can help!

[chalker7]

I wasn't sure where to post it, but I have some questions about the flight log requirements.

Firstly, when they say motor size, what exactly are you supposed to measure?

Also, how do you measure torque?

Thanks so much to anyone who can help!

Since there aren't any details on motor size, it can be any metric you like. Many people use the width of the rubber motor, but other common measurements can include mass and/or length.

You measure torque with a torque meter. A torque meter is a simple torsion spring (just a straight piece of music wire) with a hook and dial indicator on the end. You can purchase them from a few different sources (such as www.f1d.biz) or build one from a wire and some brackets (you can find directions here: http://www.indoorspecialties.com/index1 ... l&ourl=D33 )

[illusionist]

I wasn't sure where to post it, but I have some questions about the flight log requirements.

Firstly, when they say motor size, what exactly are you supposed to measure?

Also, how do you measure torque?

Thanks so much to anyone who can help!

Motor size is often measured as the width of the rubber. For example, you may have 3/32 and 1/16. These are very common starting points for members. If you don't understand what I mean, just ask.

Torque is measured using a torque meter. You can build one on your own (I'll post the instructions on how to build one when I find them on my computer somewhere). They often consist of a hook, a metal wire, and a dial. You hook the rubber on, and how much the metal wire twists will give you a relative measure of torque.

When trimming your helicopter for flight, the most useful measurements are rubber width, rubber winds, and torque. Although torque is a little more difficult to measure, I would definitely recommend recording it on your flight log.

Edit: Looks like chalker beat me to it... Oh well

[mrsteven]

I wasn't sure where to post it, but I have some questions about the flight log requirements.

Firstly, when they say motor size, what exactly are you supposed to measure?

Also, how do you measure torque?

Thanks so much to anyone who can help!

i would agree with those two above me, except I measure rubber in terms of weight for 1 of my criteria and again with the width. By size, from last years weight limit of 2 grams, that made more sense than this one.

Is anyone incorporating metal wiring for their helicopter design, outside of maybe the hook for the rubber?