I have a AofA gyrobee and a Simple G built from Jim Baxters plans now i would like to covert a Modeltek Magic that was given to be by a friend. It was crashed when i got it. I have re-assembled all of the important parts. The wing is also salvageable but a rotor would be much more fun....
As you can see it has large landing gear on it already. All i need to do is build a rotor mast and figure out the diameter of the rotor. I want left / right tilt and i will use the elevator for up and down.
Heres what i have so far....
What you see with a Magnum 36 engine 3 servos receiver and battery weights 3 1/4 pounds. Fuse length is 33".


Any suggestions?

Well, you can get all fancy with the maths or just go the 'what looks right usually is' way. Personally I would place the mast where it would give you around 8 degrees hang angle and high enough to give good rotor clearance then make blades of suitable length to give good clearance from the l/e of the fin. You might need to increase the downthrust of the engine to allow for the rotor drag well above the c of g of the plane. 6 degrees is always a good starting point.

I have attached an image of the head system I used on my DC roll gyro, its about Simple G sized so you might want to beef it up a bit for a gyro the size you are building. I have used the Simple-G type hub on models up to .25 powered and 36" diameter rotors.

Have fun

Sean

Heres the latest progress. After much thought i wanted to be able to put the wing back on the Magic and fly 3D with it also. So i fabricated the rotor mast and mounted it using the same airfoil shape as the wing. This will allow me to attach the new rotor pod or my wing in the same way. After i finish the conversion I will still have to deal with balancing the model so that it flys well as an autogyro or an airplane.

Here is a close up of the mount.

Dale,
Looks like it will fly to me..
Now get busy so you have something to fly here in a couple of weeks.
I took an old foam Cessna I had and I have done about the same. I am using electric for power. It show some promise.
See you Friday AM .
Jim

Here are tonights results... The conversion for the most part is complete. Tomorrow night i will cover the rotor mast assembly and put the correct engine on it. On Friday my hi-torque metal gear servo will be in at the hobby shop and on Saturday if all goes well it will be flying...

Here is a close up of the mast assembly..

Dale,

The Magic looks good..
I believe that Conversions are the way to go. Like Phil's Sig Kadet.

Good luck and I will be ready to see it at Cinncy.

Jim

Dale,
Phil Ploof and I have changed airplanes into Gyros numerous
times and it is a simple way out.
It appears your pylon should work, but like said be sure to have
an angle of attack and a nose down hang angle.
Rotor blade area should be enough to get a disc loading of
under 6 oz. per square foot. ( disc area divided by flying weight)
Good luck, have fun!

Hal deBolt

Hal,
My weight as it stands with all servos ,Battery and receiver is right at 4 pounds 3 ounces. I have not done the math yet but by looking at Rick Andersons rotor chart I need a 48"-50" rotor diameter. I have the rotor angle tilted back 8 degree's from the bottom of the wing saddle and the motor will have 7 degree's of down thrust. Right now it looks like my hang angle is around 6 degrees. I may have to add a little more nose weight.
Thanks
Dale

Hi Cincigyroflier,
Gotcha, and sounds like you are doing well. Will add a bit.
You say weight is 67 oz.
If you did the math you would find a 50" diameter rotor will
provide about a 5 oz/sq ft disc loading which is a useable amount.
There are two rotor angles that must be set.
First is the blade-wing angle of incidence. This angle relates to
the rotors plane of rotation.
If your blade-wing airfoil is flat bottom and you set the flat bottom at minus 2 deg (on blade hanger) to the plane of rotation
the true incidence will be about minus 1 deg which should provide
excellent rotor operation in all respects
The second angle is the rotor angle of attack to the airstream.
The airstream is also the craft's line of flight.
Assuming you expect the craft to cruise in a level attitude, the
fuselage would appear paralell to the horizon?
The bottom of the fuselage, viewed from side, represents level
flight? Use that as reference in setting rotor angle of attack.
You now have 8 deg to the wing saddle? Disregard the saddle!
Know this> this angle of attack can be from 2 deg to 10 deg to
the line of flight (airstream).
Also that rotor drag is an important consideration.
And that drag increases as quadruple function with each added
degree of angle.
The rotor must have an angle of attack to function.
Thus the angle used is a compromise.
The angle must be sufficent for the rotor to work,
It also must be such that the least possible amount of drag is
created.
The craft's drag requires power to overcome it. Thus the least drag the more efficent is the craft.
Gyro rotor drag is created in a "bad place", high above all else.
Thus the minimum amount is best.
Bottom line is> experience has shown that a rotor angle of attack from 2 deg+ to 5 deg+ works fine
A .36 engine swinging a 11x5 prop with a 3 1/4 lb craft weight
should fly briskly with a 5 deg+ rotor angle of attack.
Otherwise a 6 deg hang angle is normal
Ideal angle is determined in flight.
If craft is pitch sensative, increase angle.
If craft seems ultra pitch stable, decrease hang angle.
To perform Gyro maneuvers well pitch stability should be close
to sensative.
Boy, this message grew!! But, saw you were a bit off base and
we all do want you to have success !
Good luck!

Hal deBolt [email protected]

It is finally finished and i am ready to fly it. This weekend it will make its maiden flight( I hope) at the Cinci fly-in which is at my home field. So if all goes well my next post will include an airborne picture and a flight report. If she hits the ground and explodes[:@] i guess my next post will be an obituary.......[&o] complete with crash scene pictures of course...
Happy flying

Hello Dale...
Well, by now the answer should be known....did it fly?
Sorry I didn't make it to your fly-in, but a new knee has
gotten in the way.

Hope your fly-in is a complete success!

Bill

Yes it flys
With a few modifications to the tail to keep the rotor from taking it off. And some tweeking at the field it is now flying very well. Rick Anderson did the test flights and with the help of Rick I now have a nice autogyro conversion. On Friday my stupidity lead to a crash..They don't seem to fly very well when they loose their rotor blades. It seams that i forgot to put locktight on the set screw and the rotors came off during a test flight damaging the front of the fuse.[:@] I stayed up late repaired it and Rick had it flying again on Saturday. It is now a great flying autogyro... At least for the experienced autogyro pilot.....I on the other hand still have some learning to do..
Here are some pics that i took of it. Keep an eye out on Ricks website for the complete fly-in pics.
Dale

Great flight picture!! All of my pix come out with the blades frozen due to the digital camera "shutter" speed. Yours came out with the blades blurred, gives the impression that the blades are spinning like mad!

Nice Going Dale!

Your conversion looks great in the air and proves that regular models can be quite
easily converted to 'gyros'.

Sounds as if the fly-in was a success too!!

Bill

Hi Dale

Congratulations on your models success.

Maybe Modeltec would like to see it and offer your conversion as an add on extra !!

SO whats the next project ?

Sean

Thanks for all of the advice on this conversion. Now that some of my friends were able to fly it they are looking through their old junk fuselages for some thing to convert to an autogyro. As for my next autogyro project I think i will wait until i get good at flying the ones that i have....
Here's a picture that i am proud of, look at Rick Andersons Kellet hovering overhead....

BillF,
The fly-in was a success and NO ONE landed where you did last year. HaHA

I would like to thank Dale and his club for providing a very nice place to Fly Gyros.

We had a very good time Bill.

Jim

Dale

Thank you for having this years event. It was a pleasure to fly at your wonderful site and I hope to do so again someday.

Now on with the thread.

I have to say at this point fellas that airplane fuselages are not really set up for gyro operation.
Dale and I had to make several changes in hang angle, down thrust, chop the vert stab off, adjust the aft rotor tilt etc.
All of these changes were necessary for this great flyin model to fly. This sort of stuff is easy for an experienced gyro flyer to do but for the novice flyer it would have been impossible to do alone.
Dale should be congratulated for his efforts in creating a very nice, attractive and good flying model.

And BTW none of this was possible without the heckling of the peanut gallery that stood by and egged us on...

Warmest Regards to All.

Rick Anderson

Rick,

Well said Mr. Anderson


Jim