Xperimental Autogyro/Gyrocopter

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 This is my second autogyro /gyrocopter , but first which I am designing completely on my own

This tread is not real time, and the the design and build is going through iterations 


MODEL-1

1. Direct control head

2. two blade rotor

3. teetering head 3 D print

4. Tractor 

5. blade length -400mm

Disk loading 

 AUW 650gms ..=23/5.4 =4.26 oz/sq ft  .. 4.26x2 =8.5 





DID NOT fly

It nosed up dramatically and stalled

the blades did nor spin fast enough, the overall CG was not correct and was quite heavy




MODEL -2

1. Direct control head

2. 3 blades

3. pusher

4. additional rudder control

5 reduced wt

The fuselage is made of 10mm Al sq tube riveted together. The rotor hub was made of hardwood, with a Xray film acting as the hinge for roll control. The rotating plate was made of ply with again a Xray fil acting as the flapping hinge. It is a delta layout. The main rotating assembly comes from a 2206 outrunner motor.. the stator part


Close up of the mast head




Close up of the top of the mast head where the rotating part goes in. It is screwed into the locked nut


3 blade layout with a delta rotor hub.. notice the shims where the TE of the blades will be. This gives the required -ve AoA for rotation. The actual rotating part, including the bearings  is the stator of a outrunner quad motor


The flapping hinge .. the black part is a Xray flip sandwiched between two play plates to for the delta hub


The blades were pre-rotated with a contraption attached to a cordless drill

DID NOT fly
It nosed up and stalled






MODEL -3

decided to build a much simpler model 

1. no direct control head
2. Much lighter
3. foam rotors 








DID NOT fly properly
nose up and stall.. 




IMP aspects and learnings

1. Disk loading and disk solidity.. keep it below 1.25 oz/sq ft per blade

2. CG and rotor plane .. rotor axis should be behind CG.. or CG should be ahead of rotor axis

3. A lot depends on good blades including blade airfoil, balance, tip wt and blade incidence

less tip wt = less rpm and quick decay.. more (-)ve incidence (for a specific airfoil) =  more rpm  but less CL...  hence  airfoil for less AoI for 0 lift (part of blade which ensures autorotation) and less drag for good rpm and lift

Balance

CG needs to be ahead of rotor rotation axis

Thrust axis very close and lower than CG

Hang angle so that rotor plane nearly horizontal or very slightly (-)ve



The journey continues

MODEL-4 

WIP


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