Post by Nick BennettI'm new to RC modelling, and have just started building a Flair Piper Cub -
looking for any experiences of using an OS .40 four stroke with this model.
I'd be interested to know if there's anything I need to watch out for as
regards the engine installation in the Cub. Any recommendations for choice
of prop would also be appreciated.
Thanks in advance,
Nick
My Flair Cub is now 11 years old. I covered it with nylon and dope with
paint (yellow, of course) on top of that. The finish has crazed a little
where the nylon has flexed over the years, but then the real ones have that
effect too, so it *is* scale!
I fitted an old OS 40 FS (the pre-surpass version) from the word go and I
use an 11x6 Graupner prop (the heavy grey ones). She's quite happy chugging
around on half throttle once in the air - very scale-like too. The
difficult bit was getting a sensible run to the carburettor input arm (it's
a rear mounted carburettor, as you know) so that the arm can operate
properly without binding, but it can be done with a bit of fiddling. You
need to get the engine sat right up forward for the prop to clear the
cowling front and to do that with the FS you'll need to cut away the plywood
front former and a bit of the plastic to clear the camshaft housing and
pushrod tubes. Best done a little at a time by trial and error (that's how
I did it anyway). Once the engine sits in nicely and the prop doesn't foul
the cowling you can mark and drill the bearers. It's a long time ago now
since I built mine so I can't remember if the bearers needed any trimming to
enable the crank case to sit between them properly. I seem to recall some
sort of faff with the plumbing too - the pipes being very snug behind the
engine - but I can't remember too much about that either. Besides, Flair
might have changed the hardware spec by now (mine has a round plastic 6oz
bottle tank with a screw-on cap).
Oh yes, one other thing. My Cub has become "Old Faithful" these days but
the undercarriage has shown a tendency to splay outward slowly over time. I
keep meaning to make up another one with extra diagonal bracing wire (like
the prototype), but so far I seem to be short of those good old tuits. You
might want to think about soldering in some bracing wires from the
beginning.
Good luck with the building and flying - it's a great aeroplane.
Steve