Helicopter Testing

[Frogger4907]

3 min. The only thing keeping times so low is the 3.5 gram min.

[chalker7]

My car and engine knowledge is at a minimum. When you say transmission what exactly do you mean?

On a similar note, given last year at state, 2:00 was a very good time (achieving it = medal in most states) where do you think that bar will be now that theres no limitation on motors?

A transmission is the thing that converts the power source into useful motion (in anything mechanical, not necessarily cars). In a car it's a series of gears that changes the direction/mechanical advantage of the rotating camshaft in the engine into turning wheels.

For SO helicopters, there are a variety of transmissions that I could see working. Either a pulley system or some sort of light gear system would probably work (although you risk slipping and/or frictional losses). I also bet a team could come up with some sort of crankshaft/connecting rod system similar to those in indoor ornithropters that would power two rotors. All that being said, I think the easiest method will be to use two separate motors (one for each rotor), although that will have a number of challenges in regards to limiting weight and balancing thrust.

It's really difficult to predict times at all the various regionals and states around the country, what is competitive in one tournament might be far from competitive elsewhere. The winning time at nationals last year was just under 3 minutes and we had a lot of teams over 2. I'd expect at least a couple teams to be near 4 minutes this year.

[Lily Essence]

Not sure if this is the right thread to mention this, but tethering isn't allowed. (Or at least, if you do tether, you'd be put behind other teams that don't)

I just wanted to mention this since I e-mailed my FAQ to SciOly and they've responded, but haven't changed the FAQs yet. I kept being told by my coach and others that tethers were being allowed this year, but when I read the rules, I couldn't see how they could allow that since the rules specifically say that teams cannot steer their helicopter. (therefore, teams that do would be tier two'd) And (to end this confusion on my end) I submitted a FAQ.

Have you guys been told differently about the tethering question? I hope that SciOly updates their FAQ to reflect this, since I foresee a lot of confusion if they don't...

[mrsteven]

Not sure if this is the right thread to mention this, but tethering isn't allowed. (Or at least, if you do tether, you'd be put behind other teams that don't)

I just wanted to mention this since I e-mailed my FAQ to SciOly and they've responded, but haven't changed the FAQs yet. I kept being told by my coach and others that tethers were being allowed this year, but when I read the rules, I couldn't see how they could allow that since the rules specifically say that teams cannot steer their helicopter. (therefore, teams that do would be tier two'd) And (to end this confusion on my end) I submitted a FAQ.

Have you guys been told differently about the tethering question? I hope that SciOly updates their FAQ to reflect this, since I foresee a lot of confusion if they don't...

With my short 2-year-experience with Helicopters, to tether it has legit not even crossed my radar. What do you hope to accomplish by it? Steering isn't allowed and nothing that tethering it can do, would be considered legal. Also, it simply adds weight to your helicopter and weight is 100% the enemy. + tying a string (or cord, whatever you use) will make the helicopter off balance. Less balance = worse flight.

given that, I've also never seen one, at my regional, illinois state, or nationals.

[Frogger4907]

Not sure if this is the right thread to mention this, but tethering isn't allowed. (Or at least, if you do tether, you'd be put behind other teams that don't)

I just wanted to mention this since I e-mailed my FAQ to SciOly and they've responded, but haven't changed the FAQs yet. I kept being told by my coach and others that tethers were being allowed this year, but when I read the rules, I couldn't see how they could allow that since the rules specifically say that teams cannot steer their helicopter. (therefore, teams that do would be tier two'd) And (to end this confusion on my end) I submitted a FAQ.

Have you guys been told differently about the tethering question? I hope that SciOly updates their FAQ to reflect this, since I foresee a lot of confusion if they don't...

With my short 2-year-experience with Helicopters, to tether it has legit not even crossed my radar. What do you hope to accomplish by it? Steering isn't allowed and nothing that tethering it can do, would be considered legal. Also, it simply adds weight to your helicopter and weight is 100% the enemy. + tying a string (or cord, whatever you use) will make the helicopter off balance. Less balance = worse flight.

given that, I've also never seen one, at my regional, illinois state, or nationals.

It purpose is to hold the copter below the ceiling. But it is not allowed.

[mrsteven]

Well, theres my view on that. What do you define as steering? In a car is 2 dimensions, right left forward back.
when you get to something moving on a 3D plane is the right left forward back ONLY what steering is? I would also include up and down since in a 3D plane those are directions.

therefore, stoping it from hitting the ceiling is to stop it from going up, changing the path. Which, in my book, is steering. Which isnt allowed

[purplepenguin]

I have a question: This is my first time doing this, and I am very new to building things, but can any of you seasoned builders give me some tips on actually getting the helicopter off the ground? The design is made almost entirely out of balsa, so it's very light, but I can't manage to get it off the ground and moving. Are there any tell-tale signs that the helicopter is too heavy, or is it just a rotor (blades-not-moving-fast-enough) kind of thing? Thanks so very much!

[thedoctor]

I have a question: This is my first time doing this, and I am very new to building things, but can any of you seasoned builders give me some tips on actually getting the helicopter off the ground? The design is made almost entirely out of balsa, so it's very light, but I can't manage to get it off the ground and moving. Are there any tell-tale signs that the helicopter is too heavy, or is it just a rotor (blades-not-moving-fast-enough) kind of thing? Thanks so very much!

Well I mean you could get a scale and weigh it. But it also has to do with your design too; that is, how you designed your rotor. Did you angle it so it would produce lift or is it a completely flat blade? Is it solid wood or does it have something like a tissue covering to cut down on weight? Etc.
It also could be your motor. What kind of rubber are you using? Office rubber bands or competition rubber? Maybe you need to wind more. Maybe you need a thicker motor for more torque (and thus more thrust). All of these things affect whether your helicopter will fly. Providing more info about your helicopter will also make it easier for the people more experienced than I to "diagnose" why it isn't working.

[jander14indoor]

"purplepenguin" if this is your first time, and you didn't weigh it, it's probably not near as light as you think. Balsa is a hugely variable material. The same design can weigh anywhere from 3 to 12 gm with the normal variation in balsa. If you didn't plan and work to build a 3.5 gm copter, it most likely weighs 10 gm or more. Might still seem light, but its not. And weight is your absolute enemy to good flights.
And as "thedoctor" has already mentioned, we need more info to diagnose flight problems. What does it actually weigh. What kind of design. Rotor parameters. Rubber size, type and weight. How many winds, what torque, launch method, etc.

Quick comment for beginners. The most common fault I see in otherwise flyable designs is NOT WINDING THE RUBBER!! Everyone's afraid to break your motor at first, but without putting the energy in, its not there to make the thing fly. Wind HARD.

Jeff Anderson
Livonia, MI

[thsom]

Quick question guys, i'm new at this any my copter keeps turning on its side and moving then like a wright stuff airplane (obviously not in circles though). What causes this? Is it that the copter is top heavy or what?