rotor tilting?????

[R/cpb]

I am looking into r/c helicopters(have been in r/c cars for a few years) and am thinking about building a kit, but of all the parts that I have gone through I haven't been able to find a way to tilt the rotor, can anyone give me some help????:( :(

[11ongas]

any helicopter achieves movement by a tilting swashplate attached to the frame and rotor blades.there are different designs but all use the same basic theory of a moveable swashplate

[Dave Robelen]

Hi,
The swashplate changes the angle of the blades as they rotate depending on the servo position. This has the effect of changing the lift of the rotor from front-back or side- side or any combination. This form of control has ben with us for a very long time, both full scale and models.
Regards, Dave

[R/cpb]

I knew that 1:1 scales move via tilting the whole rotor assembly but I couldn't seem to find where to get somthing to do that on an r/c

[Dave Robelen]

Hi,
OK, we are almost together now. The rotor assembly on models as well as full scale is pivoted on bearings so that it can tilt. This is true of most all models. The reason for the tilting is the swashplate changing the pitch angle of the blades as they rotate. If you command say, a left bank, the swashplate and linkage will increase the angle of the blade passing the right side, and decrease the angle of the blade on the left. The rotor will tilt left, and the machine follows it.
I hope this helps some, Dave

[R/cpb]

so how does the servo move it???? also do you need more than one???

[Dave Robelen]

Hi again,
The swashplate is a ring that tilts in two directions, fore and aft, and side-side. The rotor system has a follower that rides on this plate so that the blade angles follow the inputs. There are two servos, one for pitch, the other for roll.
Cheers, Dave

[R/cpb]

thanx, I think I get it:)

[toywizard]

Nice explaination Dave.
That helped me too.

[R/cpb]

okay another question does anyone know of any kit for about 2-3 hundred $ ???

[Jmorgan]

The nexus is 199 for the kit...

that doens't include radio and that stuff..

um might be your best bet to buy a sim for bout 200 and fly that..

it will save u lots of money in the long run..

[R/cpb]

Sim??? do you mean a computer simulation???

[pinky]

Actally on most heli's the rotor head does NOT tilt. The main blades are fixed at 90deg to the rotor head and they only change pitch angle. Not angle of attack. The swashplate moves a "seesaw" assy that is attached to a "flybar" that has those small paddles on a short shaft. The flybar is what actually tilts for/aft and side/side which changes the helis flight attidude.

And there are a couple different heli simm's that are reasonbly good for around $20.00 USD new. Spending 200 for a simm is just not cost effective in the beginning. Virtual Flight has a simm that will teach you the basics of heli flight for cheap.

[Dave Robelen]

Hello Pinky,
Thanks for the input. You caught me by making a ditinction between "pitch angle" and "angle of attack" on the rotor blades. I had assumd that they were one and the same. When I speak of rotors tilting, I have seen a rotor strike a tailboom as a result of full back cyclic and a gust. Messy. The last heli I owned was the historic DuBro Shark, a fixed pitch machine. I remember the blades being on a gimbal with the flybar which was free to tilt in pitch and roll. There must be a bundle of different control schemes these days.
Regards, Dave

[pinky]

When I made a reference of the two I was kinda trying to seperate the difference between the blade holders changing angle of attack and the rotor head changing pitch angle. (there are so many things moving on heli's at the same time it's hard to keep them seperated) Heli's are so much fun cause there are about 2 dozen things that can go wrong at any given moment. :D

There are two types. Fixed and collective. Fixed seems to be less desirable and less common. Boom strikes typically happen when the blade swings backward in the blade holder while there is some positive pitch input to the blade holder. That ends up angling the blade tip downwards and allows it to contact the boom. I've found that on electrics using brushless motors there's sometimes real suddens hard startups that swing the blades backward hard. My heli has the auto rotation hub so I can spin the mainrotor by hand before starting the motor. Cuts down the chance of a boom strike on startup by a lot.

I only mention it for those that are still new to help the new pilots out. It was so much easier for me to fly once I understood how everything worked together.