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plane with a 60cc(4.0 lbs) on the front, and it had an insane amount of zip. With
HiTec 5945’s on the elevators, pull-pull rudder, and the 4.0 lb. engine on the front,
the CG came out right on the factory recommendation without any batteries inside.
Simply place one battery right in front of the wing tube, and one right behind and
your CG will be very close. This is just a guide, each plane should be checked in-
dividually.
We will prepare our engine box in four steps:
(1)
Calculating the engine box length
(2)
Cutting the engine box
(3)
Marking and preparing our firewall
(4)
Glue and re-enforce firewall
(1) Calculating the engine box length
{Engine Cowl length (plus) ¼” prop clearance} (minus) engine length = engine box length
To determine your engine cowl length, place the cowl on a flat counter and place a
straight edge across the top. With a rule, measure from the flat counter to the bot-
tom of the straight edge.(see figure 1) Write this number down – it is your cowl
length(CL). NOTE: The back mounting plate of your cowl is recessed ¼” from
the epoxy-glass edge. Use a ¼” shim under your yardstick so that our zero point
is the back of the plywood mounting plate.
Measure your engine
from the rear of the mounting plate to the surface that the
rear of the prop will rest. (see figure 2) This is your engine length (EL)
Figure 1
Figure 2
