It's not a good idea to try to relate the power of an electric motor to that of
a glow engine in spite of AstroFlight's attempts to do so. For instance, the
motor
I mentioned is called the Cobalt 40G because AstroFlight wants it referenced
to a .40-sized glow engine. Their rationale is that if you take this motor,
without
its gearbox, and stick 18 cells on it, you'll spin a 10x6 prop at around 10,500
rpm
which is within the range of most .40 glow motors. But, put 21 cells on the
same
system and you'll be spinning that same prop around 17,000rpm, well beyond
what a glow .40 will do. More important, with the gearbox and 18 cells, you'll
be
spinning a 13x8 at 7500rpm and producing thrust that the .40 glow motor can
only dream about. The target weight for my 1/5 scale Tabloid is 10lbs and I
will
be flying it with 20 cells and the Cobalt 40G and according to my simulated
results
(reliable for other aircraft I fly) I will have ample power. No .40-sized glow
engine
is going to fly a 10lb biplane very well :-)
But also realise that the C40G is a middle-sized electric motor. AstroFlight
makes
motors twice this size if you need the power. You shouldn't for a 1:6 scale
WWI aircraft
however.
>one of thosr flying rain gutters and you're right - it needed to be able
>to bounce off the ground as it did with frightening regularity. In fact I'm
>not sure I could say I aver became even a slightly competant flyer. All my
>flights ended with a crash rather than an attempted landing.
Unfortunately, people tend to do this and blame their ability (inability) for
the
difficulties rather than the aircraft itself. As a flight instructor I've
flown a bunch of
these Duraplanes, Durabats, Sturdy Birdy,etc. aircraft and I can tell you they
are
a handful. I had a friend who spent a year trying to learn to fly with a
Sturdy Birdy.
Every flight ended in a crash either due to a loss of control or during an
attempted
landing. One day I took him up with a buddy cord and one of my high winged
trainer
aircraft. "Wow...this is easy" was his first comment. He flew it like a
veteran and
after a couple of landing approaches (mostly to gain my confidence in his
ability
to land my plane), he put it on the runway. Within a week he had something
similar
in the air and has never looked back.
Cheers --- Larry