cadman 2

I have read in auto-gyro sites that pusher gyro's are treated differently such as in rotor angle, engine down thrust, etc. Where can I find info relating to this?

Spaced

Do a google search for gyronuts.
Theres some pusher basics in there as well as a plan for a pusher.
Hope this helps.

Gyronut

Hello

For information on Pushers please my website. www. gyronuts.com.

There you will find all the information needed to build a pusher gyro model.

Best Regards

Richard Anderson
www.gyronuts.com

cadman 2

Gyronut... I've been on your web site and I don't see the kind of info I'm looking for. Am I not looking in the right place? I need to know things like rotor angle, engine down thrust, rotor height above body, etc.

Gyronut

Hello

I will answer your questions for you.

The aft rotor tilt is just like any other model autogyro in flight. The further aft the rotor is the slower the model will fly but the model will also want to pitch up so it is a balancing act. I prefer to start at 8 deg and go down from there.


"engine down thrust"

There isn't any..........the thrustline needs to go thru the model CG or just slightly above it. Adding any down thrust will just complicate things. The thrust line should be 0,0,0.


"rotor height above body"

Rotor height is a function of where the Vert CG is located. Keep in mind that the weight below the thrust line has to equal the weight above the thrust line.. Where the thrust line sits will be wherever it has to be based on your design and the weight of all the individual components.

If you are looking for a silver bullet on model autogyro design there isn't any. We learned all this stuff the hard way we experimented and figured it out.

There are a few fella's out there who know a thing or two regarding pusher autogyro but thats about it, like Sean. Email them and they will tell you the same things I have just touched on.

Drop them a line they would be glad to hear from you.

Sean Hull [email protected]

Best Regards

Richard

Spindizzy

Whats this !!

A recommendation of info from yours truly [X(]. Careful Rick, people might start thinking that I know what I am talking about. [&:]

On the subject of setting up a pusher gyro, what Rick says it about as good as it gets. There are no real certainties for a successful setup. Just keep that engine thrustline either on or slightly above the c of g. I once changed the rotor hub to a delta type hub and it upset the whole balance of the thing, I needed to increase the hang angle by about 2 degrees to keep it stable in pitch so you can see, there are no set rules....just guidelines.

For what its worth, I use a neutral stick aft tilt of 8 degrees and a hang angle of 8 degrees with a straight hinged 3 blade rotor. Engine thrustline is about 1/4 inch above the c of g.

If you go to Ricks website www.gyronuts.com my pusher gyro is in the whirling wonders section. Its Rick Andersons own design 'Huff & Puff' that has been slightly modified for a larger .10 size engine with a poly hinged rotor hub. Due to a high c of g pushers tend to be less laterally stable than the tractor types..........well mine is anyway

Sean

ultraviper

Talking about pushers, does anyone remember the autogyro in Dr.No ? Do you suppose there are plans for that little machine somewhere ?

cadman 2

Many thanks to both of you!! I like unusal models and I am old enough to remember the autogyro that the Detroit News had in the late 30's early 40's. Also the German autogyro kite that was towed behind their early WW II subs is becoming interesting to me. I remember seeing it at Dayton in the museum. At the time I didn't pay much attension to it, but since then thru research for a sub model I found some history. Thanks again

cadman 2

Spindizzy The autogyro I would like to copy appears to have an 11 degree back angle. What problems would this give me?

flicka5

My Feedback: (2)

That is the Wallis machine and here is an image of a RC model of the Wallis flying!

DICKEYBIRD

Hi Richard, Sean, et al, can you describe how you locate the machine's vertical CG? Hang it from the nose? I'm no engineer and don't think I can calculate all the weights and moments from a plan. I'd like to do a twin-engine pusher 'gyro (I'm a glutton for punishment!) but obviously would need to get close with the thrustline before test flying it. I'd already figured on making the engines' vertical position somewhat adjustable.

flicka5

My Feedback: (2)

And another image of the Wallis!

Spindizzy

Hi Dicketbird

Just hang the model from the engine crankshaft. The more the tail hangs toward the model level position the greater the thrustline is above the c of g. I think my Puff was about 10 degrees off from the vertical as I recall. Just so long as the thrustline isnt below the c of g you can use the hang angle to get things balanced out.

Hope that helps

Sean

P.S That real pusher gyro was called Little Nellie and was in the film 'You Only Live Twice'.
Incidentally, that real gyro has its thrustline fractionally above the c of g. I met Ken Wallis the designer, he is 85 years young and still flies his gyros. Still holds several world gyro records.

boberos

Hi Rick,
Thanks for providing everyone with plans for the Huff & Puff from your website.

Couple of questions.
Is fuel draw a problem with the tank mounted so low?
Any hints on improving lateral stability if it is a problem?
As you know, I have had poor succes with fiberglass blade hinges, & great succes with PP & 15 degree delta. In fact I use that system with 6042 blades on all my single rotor gyros. Should I anticipate any problems here?

Thanks again, & anyone with experience in this area is welcome to respond.
Bob Gardner

Spindizzy

Bob

I found that fuel draw was a problem, especially when pulling in to a loop with the Puff. It would sometimes lean out too much and cut. Eventually I moved the tank to the forward strut held in place with a couple of cable ties. It works a treat and I no longer have fuel problems.

I currently use a poly hub with 15 degrees of delta on my Puff. Performance is excellent however for some reason I had to slightly increase the hang angle, nothing too dramatic though.

Its a blast to fly and i have to say the easiest and quickest to build gyro I have ever come across. Amazing that a Texan could build something so small, maybe thats why he built that monster Whistler to get things back in 'perspective'.

Sean

P.S Here are a few images that show the tank, not very good quality but you get the idea. Also thrown in are a couple of earlier images with the original tank position and non delta blades.