Designs and Kits

[jetnet22]

I would have figured putting them as far apart as possible might work best, this looks really good!

[lllazar]

For anyone having balance issues, a few tips i've learned from this past weekend:

1. Having both rotors on the same precise vertical axis helps. A lot. By this i mean you should build your copter so that the fixed rotor and free rotor are essentially 1 above the other (not distance wise, i am NOT referring to the ditance between the two rotors, just in terms of relative position).

2. Make sure your rotors are balanced. Now, assuming your building a ribbed mylar rotor (or other type of material, i think japanese tissue paper is also popular?), the wooden frame should be made of wood that is hand picked for the right mass. Use strong stiff sticks for the main long pieces, and use lighter stuff for the ribs. Make sure the mass on both sides is about the same by massing the cut pieces before hand. This helped me a lot going from my 2nd heli which was terribly unbalanced to my 3rd heli, which wobbled nowhere near as much. Continuing on, when putting on the mylar, assuming you make no mess ups and don't have to patch (and a little bit on that later), the finished product should be fairly well balanced.

3. About that patching up business. Don't even go there. Unless it's a very minute error and can be fixed with just a little bit of covering and glue, just start over. Patching up a tear that's more than a few millimeters in size is going to 1. add more weight on one side, making the rotors unbalanced, and 2. if you happen to care about aesthetic value, it just makes for an ugly copter. Either way, with a good jig, it should take less than 45 minutes to make a complete rotor, and hey i do it by myself so i would know,

Hope that helps, balance is a key to making your copter as efficient as possible.

[blue cobra]

It only takes you 45 minutes to build a rotor? The jigs I made significantly cut down time, but with all the sanding necessary to get the ribs to fit right, it still takes me much longer than that.

[lllazar]

Sanding? My jig allows me to dip the ribs into some water, and bend it along the jig and glue right in that position. With a little masking tape to hold everything down, and a blow dryer, the rotor comes out with exactly as much curvature as i want. So ya, i don't really end up having to sand anything.

But really what does it matter, it's not like towers where you build a tower or two every week (or in some cases more), the only need to rebuild would be because there has been a major change to your design or something breaks/gets stuck.

[Frogger4907]

I kind of wish kits weren't aloud... any one can throw together of kit, that professionals design to stay up for 2 min...

[jander14indoor]

What kit are you talking about? I've seen NO reports of a kit hitting two minutes, and many about students struggling to even get off the ground with a kit. So far no evidence that kits give any of advantage that I've seen. If you have evidence, provide it, we can certainly look at that for next year.

Keep in mind, the purpose of these flying events is not so much design (though there's more room in helicopter than Wright Stuff for desing surprises) but test and evaluation. Without test and evaluation, there's still no way I've seen to succeed with this event even if someone hands you a good copter.

Thanks,

Jeff Anderson
Livonia, MI

[lllazar]

Haha this is very true, my rotors as far as i can see are very well constructed and in theory the design should work quite well, but we started at the beginning getting times of 30-40 seconds. Only through testing and changing factors did we get our time up.

[lllazar]

Haha this is very true, my rotors as far as i can see are very well constructed and in theory the design should work quite well, but we started at the beginning getting times of 30-40 seconds. Only through testing and changing factors did we get our time up.

[Frogger4907]

What kit are you talking about? I've seen NO reports of a kit hitting two minutes, and many about students struggling to even get off the ground with a kit. So far no evidence that kits give any of advantage that I've seen. If you have evidence, provide it, we can certainly look at that for next year.

Keep in mind, the purpose of these flying events is not so much design (though there's more room in helicopter than Wright Stuff for desing surprises) but test and evaluation. Without test and evaluation, there's still no way I've seen to succeed with this event even if someone hands you a good copter.

Thanks,

Jeff Anderson
Livonia, MI

The River city rocket hits around 2 min according to their site, at http://www.turnertoys.com/G1/science_ol ... lanes1.htm as well as the kit below it can hit 2 min. Although I have never seen this, you can see that they say the kits are capable of two min. Maybe there not?

[smartkid222]

Although websites usually inflate the times to exaggerate the capabilities of the kits, it does seem possible for a helicopter from a kit to reach 2 minutes.