Loyalhanna Dockyard

   July - 2005

 

   MOTOR MOUNTING OPTIONS

 

               

                Last month we covered the maintenance and possible future replacement of your drive motor as something to be considered when deciding where and how to mount the motor.  This month we will look at a few options with regard to the placement and mounting of the motor to provide greater access.

          The most obvious solution is to move the motor toward the bow or stern until it is under a large enough deck opening.  While this may be an obvious choice, and in many cases the easiest choice, it is not without its own complications.  Moving the motor too far aft will prevent it from lining up with the prop shaft.  While moving it too far forward creates a longer than desired prop shaft which must be supported properly.  In either case, the balance of the hull could also be effected due to the weight of the motor.  All things considered, the re-positioning of the motor is the best idea to try first as long as the associated problems are minimized.  Consider the case where it would  be preferable to move the motor aft but the ideal position prevents the motor shaft and prop shaft from lining up.  There are at least two widely used solutions for this situation.  The first is to lift the motor up from the bottom of the hull and connect it to the prop shaft with gears or belts and pulleys.  This has now eliminated the constraints of the universal joint and allowed more flexibility to your installation options.  Another advantage to using belts or gears is that you can now turn the motor around, and have the motor output shaft face the bow of the boat. (As opposed to the motor facing aft as is usually the case)  This allows you to mount the motor over the stuffing box thereby saving space and opening up new mounting possibilities.  The major drawback to this option (besides the added cost of the belts or gears),  is that the pulleys or gears need to be properly aligned to minimize wear and frictional losses. 

          If these ideas still don’t solve the problem, you may want to think about mounting the motor on a plate and then set up some sort of guide system to allow you to slide it into position from a remote area of the hull.  I have been forced to do this on occasion and it does work, although it is not the easiest system to set up.  What has worked best for me is brass U-Channel strips and a plywood plate that slides into the channel.  It can take a while to set up but can save many problems down the road.  I will see if I can find a picture or sketch and include it next month.

          Some times there is just no good way to mount the motor so that it is accessible and removable.  In this case, I would select the highest quality motor possible for the job at hand.  The high quality level should buy you many years of trouble-free running.

          I hop that this has helped to point out some possible solutions to problems that you have encountered (or will encounter some day).  These are most certainly not the only ideas, but all of these have worked out well for me in the past.

          Next month I am going to address Rudder Control. 

 

Wishing our U.S. customers a Happy and Safe 4^th of July Holiday. 

To our Canadian customers, Happy Canada Day Weekend.

 

Don