Discussion Beginner Autogyro/Gyrocopter/Gyroplane Questions and Answers

[StephanB]

Originally Posted by Yoshio

Hello everybody!

First of all my thanks and congratulations to Mickey for this sticky.

I just have a question on you experts.

What do you think about trust vectoring a Gyro?
Is it possible/would it make sense?
Actually I’m thinking about an pusher configuration to go for that. But I’m not sure if an trust-vector-control is agile enough to control a Gyro!?

Thanks

Johannes

Johannes,
check this: http://www.rcgroups.com/forums/showthread.php?t=671143
Stephan

[Yoshio]

Thanks Stephan! Very impressing and my congratulations to the inventor!

[trikeman60]

Ok! heres another new guy to the autogyro world. Just built the PT25 and have flown it about 6 times,really scared the heck out of me a few times. What is the best way to fly this thing,flatout wide open thottle or half throttle or what? Flying it at half now,rudder turns well to the left but to the right it wants bankover hard like it dosen't have the power to pull through. Have slowed the travel rates down, put in a lot more expo than it called for, tried a lot to try to tame the beast. What do you think? Oh! also have.40 size engine aswell so it's not low on power.
HELP! Greg

[mnowell129]

Originally Posted by trikeman60

Ok! heres another new guy to the autogyro world. Just built the PT25 and have flown it about 6 times,really scared the heck out of me a few times. What is the best way to fly this thing,flatout wide open thottle or half throttle or what? Flying it at half now,rudder turns well to the left but to the right it wants bankover hard like it dosen't have the power to pull through. Have slowed the travel rates down, put in a lot more expo than it called for, tried a lot to try to tame the beast. What do you think? Oh! also have.40 size engine aswell so it's not low on power.
HELP! Greg

Generally you use throttle to climb or descend. So you need to adjust power until if flies level. Most gyros tend to roll into one turn or the other, so you might try initiating the turn then cross controlling aileron in that direction. Also you need to add power in the turns and often use lots of up elevator, especially in the turn direction that's the most difficult. Generally fly smooth and make large turns till you get used to it.

[spitfire_Doug]

Hi everybody

Im Doug and Im chasing some help on setting up my gyrocopter for flight. I have just finished building my G3PO from the plans and I have set the rotor so they spin up to flight rpm smoothly and produce lift. The trouble happens when it starts to lift off of the ground. It takes off but rolls hard to the left. I find this odd as the left side is the advancing blade and I would expect it to roll to the right if anything. The swash plate in level and no matter how much control imput I put in it still rolls over. If anyone knows how to fix this information would be much appreciated.

Thanks

Doug

[spitfire_Doug]

Hi again

I think that I have found the problem with my G3PO. After reading a post of Mickeys in the aerodynamic section I have learnt that my CG is wrong.
Mickeys text;
"As long as the rotor force vector is through the CG the model doesn't roll or pitch.
Now suppose that we tip the rotor disk up, assuming we are viewing from the side.
Now the rotor force is not through the CG anymore and is ahead of the CG. This tilts the model nose up, our desired outcome."
My battery hangs on the left of my fuselage. Im assuming that this has the same effect as the pitching of the model.

Thanks

Doug

[mnowell129]

Take some pictures and post them.
Much easier to diagnose the problem with photos.
Sounds like one of two problems: 1) rotor speed is too low or 2) You don't have the head stiffener installed.
Pics will help.
If the rotor speed is too low you are trying to lift it off with elevator rather than letting it fly off on its own. If this is the case, wait till it flies off under its own power.

[spitfire_Doug]

Mickey

Your right. I didn't install a head stiffener in my haste to fly in some good weather. Does the head stiffener stop the rotors flexing at the head because my gyro does this and I have to slow down the taxi or stop it completely for them to flex back and only when they are flexed back do they start to spin up to flight rpm. I have fixed the problem of it rolling hard to the left. I repositioned the battery underneath the fuselage. Can you tell me by looking at the pictures if my front undercarrage is too high making the angle of attack on the rotors to large while it is taxing or does it not effect the gyro in any way?

Thanks

Doug

[mnowell129]

The landing gear attitude looks ok. The Head stiffener is very important because it eliminates roll trim and the roll trim changing with speed.
The design calls for very stiff carbon fiber landing gear because soft landing gear makes it hard to spin up the rotor during taxi. You may need to double up the gear legs with something stiff before it's over and done with.
Gyrocopters don't "hurry" well. Take your time and get it right, you will be rewarded.

[spitfire_Doug]

Thankyou for this adivce, I will stiffen the undercarrage and install the head stiffener. When my gyro taxies up for a hop it loose all of its speed as the rotors spinn up and I end up with it sitting still with the rotors spinning just under flight rpm, Im afraid to add more power incase it just picks up and flips, I think this is caused by too much up elevator trim or is it just me being too soft? I dont want to push it because its a long way to a hobby shop for me as I live out of Perth.

Thanks

Doug

[mnowell129]

What is the swashplate setting? It should be about 5-10° down measured against the shaft (NOT against vertical). If it spins up and has head stiffener adding power should just make it take off straight ahead.
The flybar looks short, this causes less control. The flybar should be 290mm. The stock flybar that comes with the helicopter head is too short for this gyrocopter. Use 2mm music wire.

[HobbyCAD]

Hi There Spitfire Doug,

Good to hear of another Ozzie flying Gyro's !! Where exactly are you? I'm on the other side of the island, in Hervey Bay, QLD. Were a great bunch of flyers over here.

If you need anything for your G3PO, let me know. I have one, as well as built 3 others for friends. They are swell machines to fly.

Let me know if I can help you out, or better, invite us over for an Ozzie gyro fly-in.

Regards,

Francois

[spitfire_Doug]

Hi Francois

I live on the south coast near Albany. I dont fly in a club but I visit one in Perth and I am looking at joining it as I bored for high school in Perth. I mainly fly planes but Gyros amaze me. There flying qualitys are a mixture of heli and plane. It would be great to meet another gyro flier because I dont think there are many in Perth but I could be suprised.

Mickey
I will put a longer flybar in because it is the stock one from a heli. I checked the angle between the swashplate and it is right so I will wait for some good weather and try again.

Thanks again

Doug

[twinflandres]

Could you explain me some of these :

The rotor action is for turns ... ok

The motor speed is for what ?? Up and down ?
The elevator is for what ?? speed ?

thank you ..

[mnowell129]

Originally Posted by twinflandres

Could you explain me some of these :

The rotor action is for turns ... ok

The motor speed is for what ?? Up and down ?
The elevator is for what ?? speed ?

thank you ..

It's basically as you describe. Motor speed controls forward velocity but the model climbs when it goes faster or descends when it slows. Rotor control controls roll and pitch attitude. The interaction between elevator and speed is about the same as an airplane but with slower reaction than an airplane. Elevator is used for turns as well, like an airplane.