Some
time ago I built a very successful twin version of
the club favorite, a Wot 4, which after
being passed around the club to various owners landed in the hands
of junior member Liam Swarbrick who took to twin flying like the preverbal
duck to water. After several months
and many flights later Liam approached me to ask if it would be feasible to
make a twin of the Limbo Dancer.
Very shortly afterwards
one of the last available kits of the Limbo Dancer was purchased
from our local model shop and
work began…
It
was decided from the outset to try and keep this model as much Limbo Dancer
as possible and that the engines would go on two fuselages rather than the
wings, so the first job was to copy the fuselage, fin and rudder.
It became obvious at this stage that the wiring for the 9 servos could
get very messy with many ‘y’ leads and extensions all heading for one receiver, so after a little head scratching
(not too much, we don’t want splinters) we figured that the easiest thing
to do was to put a receiver in each fus, along with a switch, battery and
servos for throttle, rudder and elevator half,
HALF?!, yes, the elevator has two separate halves just
in case one day Liam comes across a cheap 9 Zap to try some taileron mixing…
The wing is extended by 14” which is the width between the two fuselages,
this puts the to OS40LA;s reasonably
close together to help combat isometric problems but at the same time also
gives a very wide track undercarriage to help on the ground. As
per kit, each aileron has it’s own servo but this model also has a small flap
in the centre section of the wing which is where the ninth servo comes in.
With
all the radio and both engines installed the model weighs in at a very respectable
six and a half pounds, should be a
bit lively eh
As
is usual in these cases, the day of the test flight brought very light winds
straight down the centre of the strip and nice clear blue sunny skies, perfect
(just a little writers license there!).
With the model assembled,
fueled up and checked with engines running, young Liam made no excuse in heading for the
strip excited about the first flight, he has not yet learned about test flight
nerves that we all know so well. Final
checks were made, throttles opened up and six foot later was airborne.
The
trim seemed about right to us onlookers as Liam took his new creation through it’s paces: loops, rolls, stall turns, you
know, all the usual stuff you do on a test flight. Then, lost in the excitement of it all one engine cut. Now some of us know the saying that when one
engine cuts on a twin the other keeps going to guide the model to the crash
site… well, it seems that this does
not apply to this model. It is very
easy to still do the regular routine on one engine, just a little slower!
The
favourite manouver at the moment is going in to a stall turn on one engine
then giving full power to make the model spin a full 360 degrees around one
wing tip before heading earthbound, nice.
Oh, that flap? With around 30 degrees down ‘Double the fun’
will float on for a while making for quite a walk to retrieve her.
I
will let you make up your own opinion from
the photo’s but we think it has been a very successful project. Now how about THREE fuseleges!!!
Name: Double the fun
Span: 65"
Power: 2 x O.S.40LA’s
Radio: Futaba Skysport 6
Article by Dave Coathup from Hindley Green Model Flying
Club
24st September 2001
