User Manual

When installing the floats on your model, you must check

the Center of Gravity before flying. The installation of

the floats will change the Center of Gravity, and as such,

could cause some undesirable flight characteristics or

even possibly the loss of your aircraft.

Caution: Do not inadvertently skip this step!

The recommended Center of Gravity (CG) location for

the Piper J-3 Cub is CG: 4

inches (114mm) back

from leading edge of wing at the root rib. Mark the

location of the CG onto the bottom of the wing using

a felt-tipped pen. Make sure the aircraft is upright when

checking the CG. If the nose of your aircraft hangs low,

add weight to the rear of the aircraft. If the tail hangs low,

add weight to the nose of the aircraft. Stick-on weights

are available at your local hobby store and work well for

this purpose.

The Hangar 9 J-3 Cub will typically need the addition of

2–3 ounces per float.

To do this you can use our HAN3626 lead weight strips

(temporarily add these to the top of the floats until you

have acheived the proper balance).

Now you can either tape these strips to the outside or,

as we have done, you can cut the strips into 1-ounce

squares and drop them into the nose of the float through

the access hatch. We then poured 1-ounce of epoxy into

each float to secure the ballast. Be sure to account for the

1-ounce of epoxy by removing 1-ounce of lead.

The floats are designed with an access hatch in the

front to add additional weight in the instance the aircraft

is tail heavy. Remove the Phillips screw to access this

compartment to add weight to the front of the floats.

The CG range for your Piper J-3 Cub is 4–4

inches

(102mm–120mm) back from the leading edge of the wing

at the root rib.

 Step 6

Plug the lead from the float servo extension into the end

of the Y-harness that has been mounted in the side of the

fuselage. Use tie wraps to secure the extension to the front

diagonal brace to prevent it from becoming damaged if it

is left loose to flap freely in the breeze.

 Step 7

Now that the floats are installed, go back and make sure

all the hardware has been tightened. Slide any extra servo

extension lead into the float.

Recommended Center of Gravity (CG)