Helicopters B

[jander14indoor]

While Ray is certainly esteemed, kinda violates the forum ground rules to answer explicitly AS your ES.

Alex123, cute dog, love to help, but need more specific questions to focus any answers. Otherwise we'll just point you to the wiki, back in this discussion string, and the archives. Much helicopter discussion in the past.

But 3 rotors are NOT required by the rules, so...

Jeff Anderson
Livonia, MI

[3starBlueberry]

I have a question about the single-blade rule for 2014. The only thing defining rotors is in 3e. Rotors are defined as one or more blades that rotate on a common path around a vertical axis. What is meant by common path? Is it a circle in a single plane? Is it a cylinder? Is it a cylindrical volume? If one of the latter two, what defines the height? Has there been any discussion of this, or a rule clarification?

Ray Harlan

A common path, as far as I interpreted it, means that he blade must spin in the same orbit every time. In other words, the orbit should be predictable.If that was unclear, (which it probably was) think of it this way.

The Solar System contains eight planets spinning around one central point (the sun). For simplicity's sake, let's forget about the whole Milankovich's rules thingie and pretend that the planets' orbits are always the same.

These planets, if you haven't guessed by now, represent the blades. You can have an orbit like Earth's, which is a near perfect circle. As long as it stays that way, it's still considered a planet. Same goes for blades. If you want to have a weird elliptical orbit, that's fine too.if you want your blades to be on their sides, like Neptune, go for it. If you want to be like pluto, with an orbit that dips down and pops back up, be my guest, although that doesn't sound very promising. Pretty much everything that follows Is acceptable. Have fun with your helicopters!

I really hope this helped, and I really hope I explained this right, because i suck at explaining. Thank you!

EDIT: people seem to be adding signatures, so here:

- Danie D, Student:)

[chalker7]

Just so everyone isn't worrying, there will very likely be a FAQ posted on the official soinc.org site sometime in the future regarding the single-blade/common path issue. There have been numerous questions and we are working on a detailed response that will hopefully clear things up. I don't have a specific ETA, but do want everyone to know that we're aware of the situation.
As always, anything we say here is opinion and with nuanced interpretations on engineering devices like this, the local event supervisors will have to interpret things upon inspection and we generally cannot say yes or no to the legality of a design.

[AznPr0d1gy]

Hi, guys, I have done helicopters before (since last year) and i would say I'm okay at it. But I'm fairly new to the forums and this is my first post.

So my question is what is considered a good time for this year?
Last year, 30 cm rotor helicopters holds times that a 25 cm helicopter struggles to beat (atleast with mine)


Right now, im getting around 2 minutes and 24 seconds with my 25 cm helicopter, but i dont know how that is compared to others, as im going to regional soon along with state (if i make da team)


Background info: i live in Texas but i cant tell you my school

[hogger]

> single-blade/common path issue

Could you please briefly explain what you mean by the term?

Thanks.

[[Isis2014]]

Hi, guys, I have done helicopters before (since last year) and i would say I'm okay at it. But I'm fairly new to the forums and this is my first post.

So my question is what is considered a good time for this year?
Last year, 30 cm rotor helicopters holds times that a 25 cm helicopter struggles to beat (atleast with mine)


Right now, im getting around 2 minutes and 24 seconds with my 25 cm helicopter, but i dont know how that is compared to others, as im going to regional soon along with state (if i make da team)


Background info: i live in Texas but i cant tell you my school

Yea I have the same question. I'm going to states nd my regionals didnt have helicopters.... so i have no clue as to what is considered a good flying time for a 25 cm helicopter, this year. Anyone know based on regional results?

[powderking1]

I joined my school's science olympiad this year, so I am relatively new to helicopters. I've gotten all my supplies, but the glue. I asked around, and some said model cement or super glue. However, I researched and found out that super glue is too heavy. Also, I am unsure about which model cement to get. All-purpose, or specifically wood cement?

So the big question:
What kind of glue is the best to use on gluing the balsa pieces together?

[[Isis2014]]

I joined my school's science olympiad this year, so I am relatively new to helicopters. I've gotten all my supplies, but the glue. I asked around, and some said model cement or super glue. However, I researched and found out that super glue is too heavy. Also, I am unsure about which model cement to get. All-purpose, or specifically wood cement?

So the big question:
What kind of glue is the best to use on gluing the balsa pieces together?

The brand i use is AMBROID. its all-purpose... its good bcuz it takes a while to dry so u can play around with it...but for some parts you need superglue.
Hope it works! Good Luck.

[jander14indoor]

<SNIP background> What kind of glue is the best to use on gluing the balsa pieces together?

Actually, cyanoacrylates or CA or Superglue can be as light as model cement IF USED PROPERLY. See the following article I wrote a number of years back and still linked to the flying events.
http://www.soinc.org/sites/default/file ... weight.pdf

For SO flying events, I use the THIN CA and wick VERY small amounts between the joints. If the joint is good and I don't go crazy with the glue I can assemble a helicopter with only a tenth gram or so of glue. Hard to beat that much with balsa cement. And it's SO much faster to build.

Jeff Anderson
Livonia, MI

[Skink]

Jeff,

Thank you for sharing your insight!