Three bladed rota head

[cambs flyer]

I've seen on various websites for around £99 which inc' all the linkages, swash, blade grips etc a chrome finished three bladed 450 rota head.

Is this just a fancy item if someone wanted to be a little flash say, or would it improve the flight lift, from my layman's perspective surely another blade whipping through the air would add extra drag and weight to the motor and hinder the performance, but I'm sure if nothing else it would sound the dogs nuts.

Could anyone explain a little more indeph for me please, as I wouldn't go down this road myself, but the idea intrigues me at the same time.

Many thanks too anyone who takes the time to explain.

[Aidi]

I have wondered about them too.. Would also be interested to hear any comments. Would look pretty good on a 450 with a scale body.

[jboweruk]

On real life helis they usually add a bit more power to the engine if they add more blades. don't forget though that despite extra weight, an extra blade is taking some lift too, so probly offset some of it's weight and drag that way, plus I'm guessing on a heli with 3 blades you won't need a flybar anymore, so you're losing that drag and weight?

Most real helis have as many blades as they can handle, usually 3 or 4 on military machines, on civvies it's still often 2 or 3, mainly a cost saving thing I'd guess.

[Sesame]

don't know for sure but ive always thought they were more for adding realism to scale models. there probably would be a little more drag as unlike a flybar you have drag the whole length of the blade. but if you offset that by the fact your going to be flying scale style you could probably drop a tooth on the pinion and get better flight times.

would look the nuts in most of the scale bodies available.

[Rotorhead]

If you keep the same headspeed as before, and reduce the hovering pitch, you will need about 40% more power.

If you keep the same pitch and reduce the headspeed then you wont really need to do much.

Drag rises with respect to frontal area and V^2, so reducing speed and increasing frontal area (slightly more pitch) will cause a bigger drop from the V^2, and a small rise from the extra area, the net effect is less drag.

So if you do it, if you want the extra flight time go for lower headspeed, if you want lifting power and have a motor that can handle it go for the same headspeed with a lower pitch at hovering point.

[chipbury]

I bought one of these in Hong Kong for £50 last year but have never got around to fitting it to my T Rex 450XL. I have balanced three blades (shorter than normal off some other helicopter) and am ready to go.
I'll just have to get my a*** in gear and do it.
Apparently it can be very tricky to fly so when i get around to it i'll put the training gear back on for the test flight and let you know what happens!

[Rotorhead]

I bought one of these in Hong Kong for £50 last year but have never got around to fitting it to my T Rex 450XL. I have balanced three blades (shorter than normal off some other helicopter) and am ready to go.
I'll just have to get my a*** in gear and do it.
Apparently it can be very tricky to fly so when i get around to it i'll put the training gear back on for the test flight and let you know what happens!

Shorter blades is another way to do it, less frontal area aswell.

You will find that it will tend to nose up at fast forward speed, so you will find you will be having to put in forward stick to balance that tendancy.

[jboweruk]

don't know for sure but ive always thought they were more for adding realism to scale models. there probably would be a little more drag as unlike a flybar you have drag the whole length of the blade. but if you offset that by the fact your going to be flying scale style you could probably drop a tooth on the pinion and get better flight times.

would look the nuts in most of the scale bodies available.

Dunno, if you got a scale Jetranger or Cobra or Huey, then it would make it less realistic, as those helis have only 2 blades IRL.