Types of Heli

[heliTV]

Another newbie question...

Looking at CP helicopters there seem to be certain standards ie 30,60 and 90 size for ic which I understand to be based around the size of engine (and therefore I guess the size of the heli)

What confuses me is the electric specs 250/400/450/500 etc. What exactly do these sizes mean? I thought it might be rotor size... Is a Blade 400 smaller than a Trex 450, what exactly is a 350 etc etc.

Hope someone can shed some light!!

Many thanks

[jboweruk]

Okay I'll try but not sure myself, I can tell you for a fact that yes a 400 is smaller than a TRex 450.

I think it goes on engine output and size, mine is a Blade 400 which has a 400 class motor. actually it's output is 380Kv I think...

But I think as they get bigger it also goes on blade size, ie a 600 class uses 600mm blades for example.

I'm sure others on here can far better explain it, and why it's done the way it is.

Also I think you'll find that a 550 class electric is similar in size to a 30 class nitro, and a 600 is similar to a 50 class. Then you have the TRex 700 which is actually not a 700 class at all, just to confuse the issue further it's a 90 class nitro.

I'll let some of the others clarify on it as I'm still learning it all myself.

[moyesboy]

the sizes are b it confusing.
The nitros are quite easy to understand. The number is the engine size in cubic inches (thanks to USA).

.30 runs 550mm blades.
.50 runs 600 or 620 blades
.90 runs 700 or 720 blades.

The elctrics started smaller and the first ojes were based on a speed 400 motor and got called 400. They ran 290mm blades. Then they got a bit bigger and were called 450. 325 blades.

Aligns first bigger electric was called a 600 as it ran 600 blades which is 50 size. Generally the bigger electrics follow the nitro sizes to use the same blades.

Aligns mid sized electric got called the 500 though nothing on it measures 500 (blades are 425). Others have followed suit and called their helis 500s becuase thay are the same size.

so some sizes make sense and some don't and its hard to understand. You need to look at the specs, particularly the blade size to see what size a heli actually is.

[heliTV]

Thanks Chaps
As I thought - nitros are easy to work out , electrics less so... it will be long time before I outgrow the CX2 and Phoenix anyhow... Can one assume that the smaller the heli, the more twitchy it is to fly? (contra rotators not included!)

[Mike W]

and ya forgot 60 size .. which run 680 blades

[andylinney]

Thanks Chaps
As I thought - nitros are easy to work out , electrics less so... it will be long time before I outgrow the CX2 and Phoenix anyhow... Can one assume that the smaller the heli, the more twitchy it is to fly? (contra rotators not included!)

In a word, yes....


Although my 450 is rock solid in the hover and in slow flight - it just accelerates at an astonishing pace - the 50 (600) sized stuff is a bit heavier and so has a bit more momentum to overcome - that said, with the amount of power available it's possible to move very quickly indeed.

Have a play about on phoenix with a 450, then a 600 and move onto something bigger like a 90, and finally onto the jet copter - the differences are easy to spot.

A.

[heliTV]

Thanks Andy
So in general, with electrics, the larger the number the bigger the heli then!

[andylinney]

As a general rule it's a good one... Bigger numbers means bigger heli's - but as was said ealier - have a nose at the blade sizes, that's the best indicator of how big the thing is going to be.

[heliTV]

Fair enough - thanks Andy
Going to the Bath MHC fly-in on Sunday if the weather's good so will learn a lot more there I guess! No substitute for seeing the things in real life!

[moyesboy]

and ya forgot 60 size .. which run 680 blades

Everyones forgotten those, nobody flies them anymore!

[electricsceadu]

the scale boy's haven't forgotten the good old 60
most of the common vario's, graupners are based around a 60 sized mechanic's
my vario bell 47 is a 60
the graupner jet ranger and agusta are both 60's

but the other one that has been missed is the gasser, normally with a 23-26cc two stroke petrol engine
and the turbines of variuos sizes in scale bodies

[jboweruk]

Yup, I love the sound of a jet copter... sweet.