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Fast Lad Performance . Esprit Model . Thunder Power RC

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Robbe Cuatro - Millennium - Nova - Dyna-X > Robbe Schluter 3 bladed head on Futura SE - flight report.
 
 
ben1101
Senior Heliman
Location: Wellington, New Zealand

Hi,

Today I flew the completed 3 blade head with 600mm blades, flew with a head speed of 1300 - 1500. In the hover the machine was nice and stable, was flying with 50% dual rates on pitch and roll, and 20% expo.

To my surprise I found that in forward flight the heli rolled to the left, lowering the side of the advancing blade. I would have expected the advancing side to have produced more lift. Of course it had a strong pitch up tendency, but not as strong as the left roll.

I will try out using a gy401 gyro on roll.

Ben



Helicopters: The. Best. Ever.
02-19-2008 08:01 AM
 
 
erichevy
Senior Heliman
Location: Zevenhoven The Netherlands

Did you like it?
Compaired with a flybar head, I mean?
Be very carefull when using a Gyro on aileron/elevator and start with very little gain.
I try'd a gyro on elevator but didn't liked it.
Did you fly in windy weather already?? Then things will start showing how it behaves.

Eric.

Don't wan't to show my geoduck in public.
02-21-2008 02:39 PM
 
 
ben1101
Senior Heliman
Location: Wellington, New Zealand

Hi Erichevy,

No I didn't really like it very much. The strong tendency for it to roll left at even the slightest forward speed made approaches difficult to say the least.

I still dont understand why it wanted to roll left, with a clockwise turning rotor it should want to roll right. I have correcting delta on the blades, could that be why?

I have set it up with a gyro on the roll axis. I will test it out today, I have assigned the gain to a slider channel so I can adjust in flight to find the best gain.

Ben

Helicopters: The. Best. Ever.
02-21-2008 11:15 PM
 
 
ben1101
Senior Heliman
Location: Wellington, New Zealand

Ok,

first flight with the gyro installed, had about 15 - 20% in heading hold mode, hovered fine, nothing unexpected just had to fly the helicopter off the ground, making sure as the head speed increased there was no rolling tendency.

I have a running theory as to why the machine insisted on rolling to the left, and that is that there was excessive flap back which due to precession lifted the right side of the disc. No accountability for translating tendency.

If I were to account for translating tendency does that mean I am in precession credit?? Effectively being that I am experiencing precession on precession? Or precession^2?
Maybe maths will help..

Rotor disc behavior = Precession(Precession)/Magic. Nope.

I live in wellington, NZ, the windy city.

Will test forward flight when the wind dies down, probably monday as I have the evening free.

Ben

Helicopters: The. Best. Ever.
02-22-2008 01:15 AM
 
 
erichevy
Senior Heliman
Location: Zevenhoven The Netherlands

Maybe you're swashplate driver (s2802) is not "timed" correctly?
When holding one blade over the tailboom, while giving elevator, the blade (over the tailboom) should not move at all.
If it does move, losen the swash driver and turn it to the point that no movement is present while jiggeling the elevator stick.

I remember I had to move the driver. I thought I had to advance the driver, not sure of this, it's a time ago.
I also realized it didn't work out when you followed the manual from the 3 bladed head.

Eric.

Don't wan't to show my geoduck in public.
02-22-2008 12:39 PM
 
 
ben1101
Senior Heliman
Location: Wellington, New Zealand

Hi,

The swash is phased correctly, the machine responds to control inputs on axis with no interaction.

I know that the lower the head speed on a multi head, the more you get pitch up and roll with forward speed. I have varied the headspeed in the earlier forward flight tests, but concluded that either way, Its a p.i.a to fly.

Well I will try with the gyro, and if all else fails I will have a look at starwood's multi blade sets. They look well thought out.

Ben

Helicopters: The. Best. Ever.
02-22-2008 11:52 PM
 
 
Stet
Elite Veteran
Location: Long Beach CA

the issue is not the blades or the head, it is in the mixing

You might consider the Mikado Vbar setup. I plan to get one once I survive my taxes.

keepin' it real
04-08-2008 06:11 AM
 
 
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Real Raptors . Mikado Modellhubschrauber . GrandRC

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Robbe Cuatro - Millennium - Nova - Dyna-X > Robbe Schluter 3 bladed head on Futura SE - flight report.
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