Couplings are one of those items that are often a problem when it comes to model ships. You never seem to be able to get them the right size for your model. The holes are always too big or too small for the motor and shaft that you have installed into your model. Some couplings have different sized inserts available but once again these items all added to the cost.

I have tried all sorts of ways to connect the motors to the shafts on my models. For smaller models a simple coupling made from some flexible rubber or plastic tube just relying on the friction of the fit onto the shafts can be all that is required. However as models get bigger and require more power to drive them then a more robust coupling is required.

I now make all my own couplings and I have made a few some for friends as well. So far these couplings have proved very reliable. I have used the same principle to make various sized couplings for different sized models and all have been just as successful.

Below are some photos of my larger couplings.

This is the coupling dismantled into it’s component peices. The ends are turned from 1/2″ brass hex bar and the grub screws are 1/8″ BSW. The hose is 1/4″ flexible air hose cut to the required length. When assembled this makes a pretty good flexible coupling.

This shows a completed coupling for a larger model ship. One end fits a 3.2mm motor shaft and the other end fits a 5mm propeller shaft. I have used these for several years now and they have proved to be very reliable.