New to Rotor Design/Manufacture

[Ccheese4]

A friend and I are looking into building a large model helicopter (~4 ft long). We are both new to the design of rotor blades and are looking for advice on what would be easiest and cheapest to do. Any help would be appreciated.

 

[MikeHalloran]

>Buy< a large model helicopter.


Mike Halloran
Pembroke Pines, FL, USA

 

[Ccheese4]

We don't want to buy one, that's too easy. We would like the challenge of building one. I can guarantee that it is more fun to fly something that you built yourself.

 

[MikeHalloran]

Understood. But I want to be sure you appreciate what you're getting into.

Take a look at the complexity of the mechanisms on this page:

http://www.rchelicopterfun.com/bell-mixing.html

Now, how do you feel about homebrewing stuff like that?



Mike Halloran
Pembroke Pines, FL, USA

 

[Ccheese4]

Looks complex. That's why I was looking for help. I didn't know if it was conceivable to build this.
Do you think it could be done? If not, is there a way that we could build as much of the helicopter as possible without having to do this and maybe buying this part?

 

[MikeHalloran]

It's no more complex than, say, fine scale live steam.

The problem is that a rotor assembly has to be complex in order to control the helicopter, and it has to be highly stressed in order to be light enough to fly, so it needs serious engineering, not just eyeballing.

That said, there appear to be a lot of people in the business of selling R/C helicopters and parts, so I'd be surprised if you can't find either major assemblies as components or a skeletal complete system that you can build around. Because of the complexity, the high stresses and the engineering that _should_ go into such a thing, don't be surprised if it seems expensive.





Mike Halloran
Pembroke Pines, FL, USA

 

[Ccheese4]

OK, thank you for your help. I'm sure we'll find some way to do it, whether or not we buy the parts. I appreciate the time that you put into answering my questions.

 

[GregLocock]

You can buy any part as a spare simply because they get smashed up far too often, and are so lightly built they wear out quickly.

I agree with Mike, buying one makes far more sense, maybe start building your own around the guts of it.

The blades I have are foam filled light plastic shells. I suppose balsa would do but would obviously not be as rugged, and I imagine the stresses at the roots would be difficult to control.

Anywya, there's a million books and websites out there on building RC helicopters, I'm sure they know far more about it than me.



Cheers

Greg Locock

I rarely exceed 1.79 x 10^12 furlongs per fortnight

 

[MiketheEngineer]

If you have never seen one - head down to your local R/C field and observe.

Most of these guys will be more than happy to show off their machines and answer any questions.

 

[Aerodesign]

Ccheese4,
I have been RC modeller (and now a pilot of full size aircraft) since 1972, at that time RC helis were being developed by Graupner and clever individuals. There are some simple ways of getting an RC heli flying (look up Micro Mold Lark on Google images). But you won't get good performance and it woudl be a hollow victory to simply re-invent these old machines.

My advice - buy a modern helicopter and learn to fly it well. Then start tinkering - modify specific items (blades, control system) in a way so that you can understand the effect your mod has. In this way you may discover/invent/develop something useful which can then be of use to many others.

Learning to fly an RC chopper is more difficult than full size - you will need around 100hrs of practice to get proficient in the basics. Once you have done that then consider how difficult it was for the pioneer's who did not have the benfit of modern electronics (gyro stabilized tail rotor, automatic collective/throttle mixing).

Good luck, l look forward to seeing Ccheese4 as a heli innovator!

Aerodesign

 

[Intermesher]

Ccheese4,

If you are considering something different from the normal and will elaborate somewhat on your objectives, I maybe able to provided you with some relevant information.

Dave