Alternative Drive Systems

There are a variety of methods you can use to connect an electric motor to the propshaft/s on your boat.  Probably the most frequently used method is the universal joint.  One end connects to your propshaft and the other directly to your motor (see picture right).  This is fine in many cases and is a method I sometimes use myself.  However, it may not always be feasible to mount the motor in line with the shaft, as shown in the photo right.  Or, you may wish to gear down the output from the motor to reduce the rpm and increase the torque.  This is quite frequently done in tug boats to increase their pulling power and to keep their overall speed down to something which resembles scale speed.  In some cases you may wish to power two propshafts from one motor.  This can be accomplished by the use of gears or drive belts (see pictures below).

The picture above left shows a geared system with one motor driving two shafts.  In this particular set-up the motor is actually mounted over the propshaft.  This can sometimes save space which may be required for batteries or R/C gear.  One disadvantage of gear wheel systems is that they tend to be noisy.  The picture above right shows a commercial tooth belt drive system.  It consists of: a moulded plastic mount( to which the motor fastens), two toothed pulleys and a toothed belt.  The smaller pulley fits to the motor shaft whilst the other is already fastened to the output shaft which connects to your propshaft. In this case I used a universal coupling to connect the output shaft from the belt drive to the propshaft.

The pictures above and left both show belt drive systems using 'O' rings.  Both have the motors mounted over the shafts. The system above uses plastic pulleys from a cassette recorder whilst the one on the left has pulleys which were made on a lathe