This was a fun little "impulse" project - I just got the urge to fiddle, so I did.
The Completed Boat
I started out with a little green bathtub boat, and installed a motor, and a hand-made prop cut from the lid of a can of cat food. The on-off switch is installed on the upper deck.
Interior layout, showing the motor in the bow
The motor is in the bow, held in place with silicone, and drives the prop shaft through a reduction gear. The reduction gear was probably not necessary, in retrospect.
Motor, reduction gear, and prop shaft mount
The prop shaft is a piece of aluminum wire, and runs in a very small plastic tube which passes through the hull. Vaseline in the tube provides a seal of sorts - it doesn't work perfectly, but it's close enough. The shaft passes through the coil of a clothes pin spring which holds it in the proper position to engage the motor gear.
The three-bladed prop was cut from the top of a cat food can, and it's annoyingly sharp. The brass thingie it's mounted on is the end of a control cable for an R/C airplane. It took a lot of fiddling to get it all straight enough that it didn't vibrate itself to pieces.
It doesn't go very fast, but it does go. It could really use a rudder.
© 2003 W. E. Johns