Moki - high performance powered glider

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 A pod and boom performance glider. The wing changes camber, through flaperons, depending on the flight mode... three modes : normal, thermal or speed..






Dimensions




(ignore the cg like sign near the tail.. it is the origin in the 3D software)

Wing area : 21.05 sq dm. CG at 10%SM - 65mm from LE at root cord


The wing is a re-purposed skysurfer wing which I got from a friend, and was in a pretty bad shape. The two halves were joined. Two 3x1 mm CF strip was cynoed to the top and bottom at 30% cord. The tips were clipped by 50mm, couple of holes, dents and scars filled & finished and a thin fishing line was cynoed to the LE.  The whole wing was given three coats of water based PU mixed with talc as filler, sanded between coats and finished with two coats of paint. ... It has flaperons, so the original aileron had to be cut out and enlarged. The Flaperons are 6mm balsa which has been shaped and sanded to the airfoil

The fuselage is pod and boom.. The pod is made of 3mm balsa, with some CF tow reinforcements. The boom is 12mm and 10mm CF tube. The boom is fixed to the pod at a ply saddle by two pvc hoops. The saddle also has four 3mm insert nuts for attaching the wing to the fuselage. 




The two boom consisting of two CF tubes splined together. This was more due to availability constraints. I had two different tubes (not one tube), and it proved to be a blessing in disguise. The tubes slide inside one another, there is a notching mechanism to prevent rotation, and whole thing held together with heat shrink.. (it can be dismantled) 



The wing is attached to the fuselage by four 3mm steel bolts, which thread into the insert nuts fixed onto the saddle... The alignment of these insert nuts and the holes in the wing is  MOST CRITICAL, it needs to be square and level. This activity took a good amount of precision & time to get done properly and some rework had to be done. 



The tail is a rudder elevator V-tail at 100 degree. . The ruddervators are 3mm balsa vacuum bagged with 80gsm fiberglass. There are epoxied and fiber-glassed to the boom. The servos are in the front part of the pod. The ruddervators pushrods run through snakes inside the boom and exit slightly ahead of the end of the boom. The placement of the pushrod exit hole and the horns was adjusted to ensure free movement of the ruddervators.



Electronics : 2212 1800kv motor, 30A esc, 8x4 folding prop,  4 x 9g servos (two in the pod for the ruddervators, and 1 each for the flaperons). 3S 1500mah bty.. I am using a elrs rx with vario and Vbat telemetry. 

The Thermal mode has 15% flaps and the speed mode has 4% reflex


What a flyer !!.. In thermal mode great glide, low sink, can turn tight and slow in thermals. In speed mode it is fast and retains energy. Fly long duration on thermal mode and switch between them. ... The aileron throws was reduced to 60%...  will try out with some ballast. 

One learning was the pros and cons of flaps + ailerons vs flaperons ... flaps + ailerons are be better for stall control vis-a-vis flaperons .. flaperons are simpler to build.

In case holes are drilled in pultruded CF rods, the area next to the hole needs to be circumfitially reinforced to prevent splitting and its propagation 

Mods

1. increased the AUW from 680gms to 725gms , instead of using deadweight ballast used a 2200mah bty ..

2. replaced the  2 sets of vortex generators with 2 vortilons at 76% span

3.  a 3D printed motor faring cum protector, along with a spinner was added

2.  the CG moved to 60 mm  from LE at RC ..@13% SM

 


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