Completely (almost) new Power Truck design
Click on Images for larger view.
The
NEW
American
Flyer/Lionel
SD-9
Completely
(almost)
new
Power
Truck
design
Click
on
Images
for
larger
view.
 |
For 2005 Lionel has redesigned the SD-9 and Alco PAs chassis and drive train. The frames and power trucks are much smoother and quieter running than the former made-over AC Gilbert design |
| The
SD-9
has
a
new
side
frame
casting
representing
the
prototype.
The
unit
is
not
a
true
scale
model
and
still
uses
the
short
GP
chassis
as
it's
basis
and
is
1.25"
shorter
than
a
scale
model. There are now Six wheels, the center set is driven from the motor and the spur gears drive the outer wheels. |
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The power pickup has a set of new roller assemblies on each side and on each truck. They work on my American Models track and turnouts without any problems. One may have to exercise them a bit to flex their wire so they are not too stiff. but that is a minor problem. |
| The
truck
is
held
on
the
motor
mount
with
two
screws
and
is
easy
to
service. One problem I encountered was that one unit had a bit of runout on one of the insulated wheels creating a bit of a wobble as it went down the track. This is inherent in the design of the insulated wheels which are a hold over from the legacy AC Gilbert design. |
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The
motor
has
a
generous
flywheel
and
uses
a
worm
drive.
Unfortunately
it
is
a
double
start
worm
and
the
gear
ratio
is
only
11:1
from
the
motor
to
wheels.
A
single
start
worm
would
have
improved
the
low
end
speed
in
my
opinion.
If Lionel would have slightly enlarged the well hole for the dummy truck to match the one for the power truck one could have easily made both trucks power trucks. There is room in the body to clear the second motor.
|
| The
gear
train
is
nicely
done
and
of
good
quality
and
easy
to
service
and
lubricate.
There are two traction tires per power truck. The SD-9 Drawbar pull is 8 ounces. The
Alco
PA
Drawbar
pull
is
12
ounces.
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| Here are pictures of the prototypes for the two SD-9s for 2005 | |