Taboo GT
coming soon to a flying field near you!..
Just when you thought that it can't get any better, the new and improved
Taboo GT shows up on the DLG scene. The bar is raised yet again. You get more
performance, higher launches, better floating ability, superior wind penetration
qualities in a well engineered and executed design.
It still looks and smells like a "good old" Taboo from far away. But take a closer
look and you will see quite a few things that have changed. Changed for the better.
First of all, the model went on a strict diet. The RTF weight of the plane is
now on the order of 9-9.5 oz (260-270g). This is definitely a welcome change.
It is still not your SuperGee with its 8.0 oz RTF weight, but then again you
don't have to be a talented builder like Mark Drela to build one of these kits.
Now you too can have a high performance DLG that weighs 9 oz and you don't have
to spend a year building it from scratch. The kit is still as easy to build
as all previous generations of Taboo.
How was this possible? Where did the weight savings come from? Several places.
Remember how they say, to save 20g of weight in a hand launch plane, find 20
places where you can save 1g of weight.
First and the easiest way to reduce the weight of the model is to use lighter
radio gear. Of course this only works if the model can be balanced with
this light radio gear without adding any nose weight. Since the tails of the
model were already at a minimum possible weight for a production kit, it needed
a longer nose to allow using a lighter radio gear. The length of the nose pod
on Taboo GT was increased by about 1" (25mm). This lets you use a smaller
battery pack like the 200mah 4xAAAA pack (21g) instead of the 350mah 4x2/3AAA
pack (31g) and still have the CG in the right place. Or you can go with one of
the super-light modern receivers that weigh a mere 8-9g instead of 21g for
Hitec 555. You get the idea. There is still enough room in the fuselage pod to
use your old larger radio gear components if you want.
The weight of the structure was also reduced on Taboo GT by employing some
innovative engineering ideas. One such idea was extending the tailboom forward
just short of the front bulkhead and eliminating the unnecessary part of the
nose pod under the wing. The tailboom serves a double duty here: it becomes part
of the underwing fuselage structure and also a ballast chamber. The fuselage
weight went down by approximately 10g as a result of this change. And in the
process it also became a lot more "sexy" looking.
The wing design went through some major changes also. The main structural
change was in the spar design. The new spar is utilizing very strong and light
pultruded carbon rods. The fiber content in these carbon rods is much higher
then in a hand layed traditional spar. In other words you get a lot more strength
for the same weight. The new spar design along with some reduction of the
wing area brought in another 10-12g of weight savings.
The lower flight weight of the model allowed for a considerably reduced wing area.
The wing area of Taboo GT is lower by about 40 square inches than the wing of Taboo XT
while the floating performance is actually improved. Though this wing area reduction
may seem insignificant, remember that
every additional square inch of wing area is working against you when coming back
from a thermal in a stiff breeze. The wind penetration ability is adversely affected
by the excessive wing area.
But lower weight and wing area are not the only improvement of Taboo GT over the
previous design. One change that may surprize you is the choice of the
airfoils. What can be better than an airfoil from Mark Drela? Another airfoil
from Mark Drela! Taboo GT uses AG45c-AG46c-AG47c airfoils from the original SuperGee
designed for 3 degrees of flap deflection. They were superceeded by the
AG455ct-AG46ct-AG47ct airfoils of the SuperGee-II
with a slightly thicker flap designed for 2 degrees of deflection. The thicker flap
had an improved flutter resistance in exchange for some reduction in the high lift
performance. These latter airfoils were then used on most of the commercially
available DLG models including Taboo XL and XT. Well, it turns out that the thinner
flaps are not a problem for the Taboo wings whith the flap servos located far
enough outboard. And a slightly better high lift performance is a very welcome
improvement for the Taboo GT wing and makes it a great floater.
The last design change that is worth mentioning was based on the premise that a lot
of good things happen to a DLG model when the weight of the wing tips is reduced. The
launch improves due to the lower rotational inertia. The performance in active air
improves because the model is easier to get into a turn or to stop rotation when
needed. The model starts showing lift better. Therefore a significant effort has
been made to
shift the area from the tips to the center of the wing. This involved moving the
tips forward in combination with some washout to unload the tips.
The result of all
these efforts is a great competition DLG model which excels in both calm and windy
conditions. It's guaranteed to give you hours of enjoyment whether you are a serious
competition pilot or just a weekend sport flyer. Give it a try, you won't regret
it!
First and the easiest way to reduce the weight of the model is to use lighter
radio gear. Of course this only works if the model can be balanced with
this light radio gear without adding any nose weight. Since the tails of the
model were already at a minimum possible weight for a production kit, it needed
a longer nose to allow using a lighter radio gear. The length of the nose pod
on Taboo GT was increased by about 1" (25mm). This lets you use a smaller
battery pack like the 200mah 4xAAAA pack (21g) instead of the 350mah 4x2/3AAA
pack (31g) and still have the CG in the right place. Or you can go with one of
the super-light modern receivers that weigh a mere 8-9g instead of 21g for
Hitec 555. You get the idea. There is still enough room in the fuselage pod to
use your old larger radio gear components if you want.
The lower flight weight of the model allowed for a considerably reduced wing area.
The wing area of Taboo GT is lower by about 40 square inches than the wing of Taboo XT
while the floating performance is actually improved. Though this wing area reduction
may seem insignificant, remember that
every additional square inch of wing area is working against you when coming back
from a thermal in a stiff breeze. The wind penetration ability is adversely affected
by the excessive wing area.