Old Airboat
This is a fun model that I made after taking the Jackson outboard motor off of this old Action Man Assault Boat and fitting it to the new Action Man Amazon Dinghy, this boat is flat bottomed and would make a good air boat, in order to convert it I built a wooden framework to hold the motor and prop unit but I didn't want to damage the hull in any way so the whole thing just sits in the hull and the weight of the nicad battery holds it in place whilst running (the battery was not installed when I took these pictures).
The receiver sits in an old servo mounting tray, with it's aerial fed along the side of the wooden frame to an aerial tube mounted at the back (where it won't get sucked in to the prop and chopped up). The steering servo is screwed to the side of the wooden frame and controls the two rear vanes by a pushrod, the vanes are linked together via another small pushrod - as can be seen in the photo's.
The two rear vanes are made from old model helicopter rotor blades, these are ideal as they have a solid metal rod running up the leading edge and are aerodynamically shaped, all I did was cut them to length but leave 1/2 an inch of the metal rod sticking out of the top and bottom and mounted them in brass tubing, the bottom of each blade rests on the plastic control horn. The model is balanced by having the steering servo on one side and the speed controller on the other with the battery and receiver in the middle of the hull.
The 540 motor is mounted in a gearbox unit made by MFA, by gearing down the motor it allows me to use a larger more efficient prop (I found that an 8x6 prop gave the best thrust/duration combination).
The speed controller is an old Firefly unit which does have half speed reverse - very useful in an emergency but the model is not steer able in reverse. This is screwed to the side of the wooden frame. A receiver battery is not needed as the speed controller has battery elimination circuitry.
The whole thing took me most of a day to make - mainly waiting for the glue to dry and is a good change from your usual model boat. The model runs for 10-15 minutes depending on type of batteries that you use, I use Cadnica 7.2v 1700SCE's.
This model has now been scrapped since purchasing the Swamp Dawg and will be re-used as something else.