Garden Cub
 

Indoor or garden slow-fly,semi-scale Piper J3 Cub.

Check out Michael Brix Hendrikssens site in the Netherlands for more pictures and information on his own versions of the Garden Cub (and a few other nicely constructed a/c). One of the benefits of e-plans is the ability to easily scale models up or down to your own requirements !

 

Winter (and often Summer :-) here in Scotland can sometimes not be conducive to flying outdoors and, not wishing to miss out on some flying, I decided that an indoor r/c electric was the way to go. Having seen some of the pictures and reports at the E-Zone, I thought it shouldn't be too difficult to "roll-my-own". I'm not a scale flyer by any means, but felt that some of the indoor models lacked that "something".

So, having decided to build, how do you select a model? I'd like to say that I spent months poring over scale model books and magazines for a suitable subject - I didn't - my friend Mike had a plan for a rubber Cub and I had a few pictures - and the Cub is the right "shape" - so that was it !

I presume other people have built aircraft exactly the same way, but if they have, I haven't seen it. The principle is to cut the foam into sheets and build it just like a balsa model - makes life very easy and doesn't require too much thought. The wings are wire cut to section using special universal templates

I used a couple of different techniques in some places - the windscreen and upper front fuselage were heat formed (hair dryer and Coke can :-) to get the correct shape - saves having to make templates to hot-wire cut foam block. The wheels were turned from the same foam and fitted with dowel centres - I used a lathe, but it's just as easy with an electric drill - once sprayed with matt black acrylic, they definitely look the part. The idea wasn't mine I'm afraid - I wanted to use the light rubber foam they use on "flip-flops", but I couldn't find any and my friend Mike suggested the same styrene foam (I have to admit that I baulked at the idea at first, but after many take-offs and landings, they are still 100% intact and look the part ).

First flights (as usual with any new model:-) were a bit scary - new model, never flown r/c inside before, lots of free-flight indoor folks watching - but I got away with it. I'd like to say that it flew perfectly first time - it didn't - there was insufficient rudder authority, so I resorted to taping another piece of "non-scale" foam to the rudder - this cured it, but it looked nothing like a Cub fin :-) Another member at the club suggested making it all flying - this is what the final version has, and works extremely well. I built a second Cub for my friend, making a few modifications in the process - more dihedral and the all flying rudder (hereinafter referred to as an AFR ) - he added his gear slightly forward and pushed the CG about 10 to 15mm forward of mine and, on the first flight it flew PERFECTLY - very slow and very controllable. I have since modified the prototype by changing to an AFR, adding more dihedral and moving the CG forward - it too flies perfectly - and SLOOOW (well slow is relative - probably closer to a brisk walk or a slow run - or approx 2.5m/s in real money :-)

Indoor r/c flying certainly adds another dimension to flying (actually another five to be precise - four walls and a ceiling - all of which have to be missed !!! )

Technical Details...

Span
 1200mm (about 48")
 
Area
 1200 dm^2
 
AUW
 260g (8.5oz)
 
Wing loading
 113g/dm^2
 
Motor
 Simprop "Slow Drive 250"
 
Speed Controller
 Jeti JES 05 BEC
 
Prop
 APC 254*120mm (10"*4.7") (comes with Simprop slow-drive pack)
 
Battery
 6 * 110mAH Sanyo
 
Flying speed
 Brisk walk :-) (approx 2.5m/s)
 
Rx
 Multiplex Nano or Jeti
 
Servos
 2*JP Perkins Naro or Hitec HS50
 


Construction...

Fuselage
 4mm polystyrene
 
Tail surfaces
 5mm polystyrene
 
Wings
 6mm polystyrene (clark - Y profiled)
 
Wing struts
 3mm shaped dowel
 
Wheels
 58mm dia turned polystyrene
 
Finish
 Either bare foam, or sprayed with Tamiya/Humbrol Acrylics
 


The Plans

Note: The plans are free, but the copyright © is MINE! (basically, don't start selling kits commercially or I'll get annoyed and send someone round to break your legs :-). 

Before downloading, please make sure you get the correct flavour for your computer /application. The plans were originally generated on my Macintosh using MiniCAD (or to be correct now - Vectorworks), but for all you computer luddites out there with PCs, I have included a DXF version (release 12 as this seems to be the version that most applications support). I have NOT included GIF or JPG files as they are totally useless for accurate plans. The DXF file has been checked on a Mac and PC using various applications - MiniCAD/VectorWorks, AutoCAD R14 (yukkk!), Turbocad, DenebaCAD among others - so don't come moaning to me saying that your 15 dollar PC program can't make sense of them ! (be sensible, go out and buy a Mac and a copy of Vectorworks :-)

All the files are in millimetres !!! ( we don't do Imperial units here - 95% of the world use the metric system, and I have ten fingers - not twelve - and FYI, Wilbur and Orville were metric :-) There are two sheets to the drawing - A0 size - the main plan and a sheet of parts outlines so you can cut out all the bits and stick them to the foam without destroying your plan :-)

