Designs

[chalker7]

Does it still count as a non-coaxial copter if one rotor is vertical i.e. do both rotors have to be horizontal for the 3x score?

Submit that as an official clarification

[wlsguy]

Does it still count as a non-coaxial copter if one rotor is vertical i.e. do both rotors have to be horizontal for the 3x score?

Just my opinion but....

The rotors are defined in the rules as " ... surfaces that contribute lift by rotating on a common path around a vertical axis"
Since the rotors you describe are not vertical, they would actually be propellers which would be prohibited.

[Bob8372]

Does it still count as a non-coaxial copter if one rotor is vertical i.e. do both rotors have to be horizontal for the 3x score?

Just my opinion but....

The rotors are defined in the rules as " ... surfaces that contribute lift by rotating on a common path around a vertical axis"
Since the rotors you describe are not vertical, they would actually be propellers which would be prohibited.

Thanks for the input, I was just wondering if a copter with a tail rotor would be a) legal and b) "Chinook Style"

[jander14indoor]

As usual, this is not site for clarifications, what follows is only opinion, etc.

You've asked two questions.
Is a copter with a tail rotor legal. I don't have the rules handy, but I don't remember anything against that.

Is such a copter a 'chinook' bonus copter. As state previously, for purposes of these rules rotors are defined as having a vertical axis. As the tail rotor isn't vertical, for purposes of these rules, I don't see how it would count as a second rotor for the chinook bonus.

As mchalker7 said, clarifications make such things official if you aren't sure of a rules interpretation.

Jeff Anderson
Livonia, MI

[chalker]

Has anyone ever seen a helicopter with a tail rotor in any venue? It seems to me it would be extremely hard to get it tuned just right so it doesn't spin out of control, and there wouldn't be any advantage in using it other than the 'looks cool' factor.

[chalker7]

Has anyone ever seen a helicopter with a tail rotor in any venue? It seems to me it would be extremely hard to get it tuned just right so it doesn't spin out of control, and there wouldn't be any advantage in using it other than the 'looks cool' factor.

Yeah, the Penni Copter plans/kit have a belt driven rear rotor. http://www.dream-models.com/docs/penniFFhelicopter.pdf
I've seen a couple of those, but I agree that it probably isn't necessary/helping anything.

[StaticBridge]

What would be the expected cost of building a helicopter?

[illusionist]

What would be the expected cost of building a helicopter?

Honestly, each helicopter costs me at most 3 dollars. Wood is quite cheap, and you can by rubber for a decent price. That's one thing I really like about this event.

[chalker7]

What would be the expected cost of building a helicopter?

That's going to vary a bit, because the overall cost will depend on if you buy your materials in bulk and what quality of materials you buy. I would say a competitive helicopter could be constructed for as little as a couple dollars per helicopter (or even less, if materials are bought in bulk), whereas some kits run as much as ~50 dollars. 10 dollars or so should be a good starting point for an inexperienced builder.

[wlsguy]

What would be the expected cost of building a helicopter?

Based on your question, I'm going to assume you have never built one.

Please take a look in the Wiki. It is the best starting point. http://scioly.org/wiki/Helicopters

You will need supplies from your hobby shop.
Balsa
Tissue paper, mylar film, or produce bags
spray glue
some prop bearings,
and a few other odds and ends.

You will also need a plan. You can look at the many photos, check the "river city rocket" on the image gallery, or buy a kit to get you started.
Some of the many shops with supplies are:
http://www.freedomflightmodels.com/paypal.htm
http://www.a2zcorp.us/store/