Autogyro

Always wanted to build an autogyro, and finally built and flew one . This thread  has snaps and writeup on the build.
This is based on the “twirl”  of which there is a lot of info on the web.. here is the link http://my.pclink.com/~dfritzke/twirl.pdf. 

There are some changes to the materials used vis-à-vis the plan, and they are fine so long as AUW (@200) is kept under check and structural integrity is not compromised. Mine was made out of 5mm biofoam , and CF scraps which I had.

The plan is fairly simple. The parts  are cut out of 5mm biofoam..I have used a 3mm cf rod in the fuse  for strengthening the fuse along with the doublers at the nose end. Note the front end is cut at an angle which has the downthrust built it. Also below the wing mount I have glued in some scrap foam to have a bit more area for the wing to glued to. 

The undercarriage spring wire is fixed to a small block of wood I fixed it by bending the wire, tying it with strong thread and covering the whole thing with cyno.. use your best  method which will give a light and rigid UC.. Once done the wooden block is glued onto the slot in fuse and taped up with fiber tape.

The tailplane is very simple. The dihedrals at the tips actually adds to the rigidity

The wing has a fairly large dihedral. In my build  the CF for the trailing edge was only for half portion of each span….. (ran out of CFs). …. and I omitted the reinforcement on the pylon. NOTE : the mounting pylon template is critical .. the 85 degree to Z axis .

The Rotor is the most critical part.. though not very difficult. The rotors are cut from 3mm depron foam. The paper pasted on the leading edge gives them the rigidity (along with centrifugal force.. but primarily the paper). After cutting out the 8 rotor blades, plus one or two spare, stack them together and check for alignment in size. .. sand in case required to have all of them of the same size. To make the paper stick properly rub the relevant side lightly with “scotch brite”….. the paper is stuck with PVA glue diluted with 50% water. … ensure that no wraping of the blades  takes place by placing then on a flat surface with weight on top.   First the center wooden block was aligned and stuck to one rotor disk. The rotors were then aligned properly and held in place with pins  and stuck with foam safe cyno ... Once set the top rotor disk is glued after aligning. … I used a thin wire (piano/spring) for the initial alignment and then enlarged the hole with a drill to the required dia…. In my case 4 mm.
Since I did not have a 2 mm CF, I used a 3 mm CF rod as the rotor post glued onto the foam pylon. The rotor hubs has a CF tube with a ID slightly larger than the post OD.. a bit of play is fine.. but not too much.

The rotor post are rubbed with soft graphite pencil to give it a coating which acts as dry lublicant. The rotors are placed and checked that they  rotate very freely… this is crucial. Once done the stoppers are put. I used the earthing terminals of 15 amps plugs for the same.  The same is tightened and also hot glued so that it does not come out during flight … this is again crucial

Once everything is fixed and electronics checked the final adjustment of CG.. the CG is at 50% of wing root chord and  the bty should be positioned so that the craft balances here.  I found that normally the build is nose heavy and the bty has to be placed behind the CG…
Motor : 1200 KV odin
Prop : 8X4.7
ESC : 25 amp(you could do with lesser amp esc.. I did not have one hence used this)
BTY : 1000mah 3 cell (you could do with a smaller 3 cell bty.. I did not have one hence used this)
Servos :  2 X 9 gm servos
AUW : 219 gms … all incl. electronics except bty

A short video of the flight

https://youtu.be/etIBoSFbdfo