Piper Cub


Piper Cub


 
  wing span   120 cm (47.2 in)
  wing area   23 qdm
  lenght   80 cm (31,5 in)
  weight   540 g (19 oz)
  wing loading   24 g / qdm
  motor   Speed 280 geared 5:1 (Simprop)
  prop   APC Prop 10 x 7
  battery   7 x Sanyo 1000AA (H´┐Żleinlibelle)
  r/c   Quite heavy: An old Multiplex receiver, Kontronik Easy 300 ...
 


Translation made by Altavista...
The Cub is scratchbuild with Selitron (a foam like Depron) following a plan by Neil Gillies.
Here`s the plan as DWG-file or as PDF 1 and PDF 2. I hope the PDF works on your printer...

Plan   Parts


Fuselage

Fuselage

The fuselage is built following the plan, only within the rear area I took 7 mm Selitron.
In the front area I built an additional horizontale balsa plate to mount the engine after the first crash.
Everything is glued with the polystyrene CA, but sand the surface always before glueing, then it the stuff really glues...
Into the balsa the core holes for M5 are drilled, hardened with CA and cut then the threads for the wing fixing bolts.
The engine frame consists of balsa plywood, in order to be able to screw the engine in.
I took the angle of incidence back during flight testing by 1 degree on 8 degrees, which maintain emphasis.
The curved sections I bound on a tin can of 10 cm diameters and taped it (important, because the material expands in the heat). Then heat it for 1 min in the oven (gas level 4, 220 degrees C). Take it out, cool it down and the Selitron looks, as if it would have never had another form.

Tailplane fin

Tailplane fin

The rudder is laid out as pendulum control unit. A 3 mm carbon rod runs in an aluminum tube, the plywood rudder horn is with Epoxy glued on and is secured with a disk and a piece hose.
The two elevator fins are likewise connected with a carbon rod, to which the rudder horn is fastened.
The hinge consists of tape.

Wing

Flying

The wing is pulled over an edge in profile, whereby one should pay attention to the " grain " of the material. The lower surface a pine spar is glued on.
I had add a small piece, because the plate was too short
All gluings are made with transparent tape here.
Deviating from the plan I replaced the props by a stringd, which runs under the fuselage along and takes up at two wire eyes, which are fastened to the pine spar, the bending forces.


Chassis

Start

That chassis is curved from 2.5 mm wire , the wheels are cut from Styrodur and bowden cable external pipe are glued in as storage.

Flying

In the morning

The model is now twice as heavy, as intended and thus mutated to a park flier .
Those first flight tests ended with a crash, since the adjustment angle was much too large by any building defect.
After the correction the model flies now extremely smooth and scale-like.
The climbing performance is naturally not that good, but evenly original faithful and although always enough power, if it becomes tricky.
The flight duration amounts to approximately 20 min with a batterycharge.
Up to wind force 3 it goes completely properly, most beautifully, is it however in the morning with zero wind...
Result
Recommendable for cosy humans, who want to save some money and require a scale-like model. By Selitron and rapid adhesives it takes only two evenings to be RF and a you learned a lot, listening to the radio...

Flying

Flying

Flying

Flying

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