Folding Flyer - by Norvel

11 Jul 00 - Night lighting photographs added.

folding-flyer-logo.gif (14167 bytes) folding-flyer-01.gif (81923 bytes) folding-flyer-02-t.jpg (1974 bytes) folding-flyer-03-t.jpg (1931 bytes) rip.gif (3013 bytes) The graphic logo is scanned from the packaging.
N of launches / Time 3 0 hours 10 mins


Wingspan 30.0 " 0.762 m    
Wing Area 285 in 18.4 dm    
  With 7 Sanyo 500AR or 600AE cells or 10 x 600mAh NiMH  
Flying Weight 1 lb. 3 oz. 0.55 kg    
Wing Loading 9.9 oz/ft 29.9 g/dm    
Wing Cube Loading 7.0 - Trainer  
Motor 5 Star Products Stinger 400 (a hot 7.2v Speed 400 motor)
Gearbox Modelair-Tech GB-50, ratio 2.14:1
Propeller Graupner 8" x 4" Slim
Batteries 7 Sanyo 500AR, 7 Sanyo 600AE, 8 Sanyo 800AR or 10 NiMH 600mAh
Speed Controller Schulze slim-25be - 35/33A - 6 to 12 cells - BEC & Brake
Receiver Jeti REX 4 micro - PPM - 4 channel - 35 MHz
Servos Ailerons - Union ultra-micro UM-9G
Elevator - Union ultra-micro UM-9G
Static motor parameters  3:1 gearbox with Revup 9" x 6" - 7 Sanyo 500AR cells gives 6250 RPM @ 13.2A, producing 12 oz thrust and estimated 45W/lb. (output) after 30 seconds.

2.14:1 gearbox with Graupner 8" x 4" Slim propeller - Untested as yet.

Flight performance 3:1 gearbox with Revup 9" x 6" - Flies well, although it is quite unstable. Climb out is about 15, loops are possible from level flight and it rolls reasonably well. Flights of approximately 2 - 3 minutes are all that you get.

2.14:1 gearbox with Graupner 8" x 4" Slim propeller - Still unstable, but flight performance is just as good, but duration is noticeably better (~4 minutes).

6 Aug 99 - This model is constructed from foam board (foam core with paper either side) which has had the pattern printed on to it. Construction is quite straight forward, despite the sketchy instructions. Whilst an ounce over the maximum weight given for the model, 3 ounces can be saved using the smallest pack and 1 ounces when using the NiMH pack. I made a few modifications whilst building the model.
1.    I converted the model to bolt the wing to the fuselage instead of using rubber bands. This will have made a marginal weight saving as the nylon bolts and spruce plates weigh less than the dowels & bands.
2.    I didn't like the idea of the elevator dragging on the ground so I have taped on a small tail skid.
3.    I fitted a rudder to the model.

16 Jun 00 - I have removed the rudder servo as it did very little and the rudder is now taped central. I have been having problems with the extremely soft output shaft of the gearbox bending on landing. This due to the small wheels causing the model to nose over due to the drag of the grass. I have fitted a Modelair-Tech GB-50 gearbox, which has a lower ratio of 2.14:1 and will require a smaller propeller. A have decided to try a Graupner 8" x 4" Slim Propeller as with ElectriCalc this gives the right sort of currents (~12A). I have increased the number of cells in my 600mAh NiMH pack for the Pinocchio and that pack will be tried in this model. I can also fit my 8 cells pack of Sanyo 800AR's, which are about 4 oz. (130g) heavier than the other packs. The wing loading rises quite a lot to 12.2 oz/ft (37.0 g/dm), but the Wing Cube Loading is still only 8.7, which is between the trainer and aerobatic groups. We'll see how well it flies in this heavier condition.

28 Jun 00 - I will shortly be attempting night flying and was looking for a suitable, stable, model that I didn't mind damaging to use. The Folding Flyer didn't meet the stable criteria, but I wouldn't mind if it was damaged. I, therefore, decided to try and improve the stability by making a new wing. This wing would have dihedral, slightly more wing area and a higher aspect ratio to improve handling. The increased wing area will help offset the modest weight increase due to the Glowire illumination system. The total weight of the system I will be using is 1oz. (43g). The system contains a driver, that runs from a spare RX output and 3 lengths of electro-luminescent wire. Two of the wires, 30" (760 mm) each, are intended for running from the fuselage down each wing, and the third, 36" (915 mm) to run back along the fuselage to the tail. The current drain is only 270mA, which shouldn't cause a problem for most BEC outputs provide you aren't at the stated maximum number of servos for the number of cells in your pack. The light output is really good and sheds a lot of light onto the aircraft structure. When I have completed the modifications I'll post a night photograph with the system on (and possibly off).

10 Jul 00 - I managed to get some night flying in on 7 & 8 Jul 00, which was actually fairly simple. Orientation was not very difficult with the Glowire system and I looped and rolled the model during the flights. However, during the night flying the temporary replacement wing folded up. This was due to the paper covering getting wet and breaking. If I'd covered the model properly, or waterproofed it, the wing would have been OK. The model nose-dived into the ground from about 50 feet and badly damaged the fuselage. The original wing is still immaculate (it wasn't fitted) and I think I'll produce a Folding Flyer biplane - should be an interesting experiment.

11 Jul 00 - I received the night lighting photographs in the post today, and I have added them above. It is amazing that the green wire (starboard wing) highlights the white lines on the fuselage, whilst the red wire makes them almost disappear. It isn't visible in the photographs, but the white wire runs under the front of the fuselage to the leading edge of the wing. This piece of the white wire was extremely useful and it would have been more difficult without it.

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