G3po

[Spadinator]

Hello all......I have researched the tractor and pusher designs and have decided to start with a tractor and move on later to a pusher. I have looked at the G3PO but cannot find any info on the blades or head. Does any one out there have the plan for the head and blades? I should say that I am not looking for the collective pitch head :)

[mnowell129]

Hello all......I have researched the tractor and pusher designs and have decided to start with a tractor and move on later to a pusher. I have looked at the G3PO but cannot find any info on the blades or head. Does any one out there have the plan for the head and blades? I should say that I am not looking for the collective pitch head :)

G3PO is my design as is BEGi (pusher) You can get every construction detail at
http://www.rcuniverse.com/forum/How_to_build_G3PO/m_2380064/tm.htm

There is a similar thread for BEGI at RCU as well...

You can post questions re:G3PO or BEGi (pusher version) to me here or at RCU. I monitor both.

mickey (mnowell129)

[Spadinator]

Thanks!!! :)

[Spadinator]

Oh I just thought of another question.......Does anyone have a plan or drawing for a two bladed fixed hub? or....can I adapt a delta style hub for two blades?

[Spadinator]

Bump???????

[mnowell129]

Bump???????
the answer is that a two bladed fixed head is unstable. Thats probably why
there are no designs available.

[Spadinator]

Ok.....what about a "delta" type head with blades that flex up. Will that help with stability?

[mnowell129]

Ok.....what about a "delta" type head with blades that flex up. Will that help with stability?

Two bladed heads are unstable in model form, period.

Delta doesn't fix this.
If you want a two bladed head your choices are pretty much:
1) Put a wing and horizontal tail on.(Whistler, and all the derivatives)
2) Use a flybar to stabilize the head.(G3PO)
3) Use very large weights in the blades.(On my todo list)

Delta does not create stability.

The stability of a rotor is determined by rpm, blade mass, flapping hinge stiffness, hinge offset and number of blades.

High rpm, two light blades, rigid rotor is the least stable.
Low rpm, multiple heavy blades, large hinge offset with flexible flapping hinges is the (relatively) most stable.

Delta reduces the amount of flapping amplitude required to balance asymmetric lift due to forward flight. Since it reduces the amount of flap, it also reduces the amount of fixed roll trim needed in forward flight. Delta is commonly used in helicopter tail rotors to keep them from flapping and slamming into the tail boom or stressing the tail rotor axle.

If you intend on using a two bladed head controlled with rudder and elevator you can use a small stabilizer bar on the rotor to make is stable enough to fly.

mickey

[mnowell129]

This is a toy with a stabilizer bar stabilized, two bladed, high hinge offset, loose flapping hinge design.
I found two of these on the clearance rack at Kmart for $20.
They are very stable.
You could copy this head design for a gyrocopter and just use rudder and
elevator to fly.

http://www.tycorc.com/us/product.asp?category_type_id=19&id=11793&category_id=7836&nostore=0

about $40 on ebay...

mickey

[Spadinator]

Cool....thanks for the info it is very helpful!!! :)

[realglow]

This is a toy with a stabilizer bar stabilized, two bladed, high hinge offset, loose flapping hinge design.
I found two of these on the clearance rack at Kmart for $20.
They are very stable.
You could copy this head design for a gyrocopter and just use rudder and
elevator to fly.

http://www.tycorc.com/us/product.asp?category_type_id=19&id=11793&category_id=7836&nostore=0

about $40 on ebay...

mickey

I found several of these recently in the east TX area for $10 at Dollar General stores. They have a speed 400 gearbox, a 8 or 10 cell nimh pack and a large gelpack charger. Not to mention the RX and TX - single channel unfortunatelly.
The rotor is pretty heavy. All in all, tho, worth the $10 just in parts.

RealGlow


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