The running gear for a model ship can be pretty expensive if you have to buy the lot, particularly if you are building something big. Long brass tubes, stainless steel shafts, A frames, couplings, multi bladed brass propellers, rudder posts and rudders, it all adds up. If you are able to make even some of the bits yourself then you are likely to save yourself a few dollars and have the satisfaction of saying that you built it.
I have been building all of the running gear for my models from some years now. I have used all sorts of materials successfully, often whatever was at hand.
In my opinion things like stainless steel shafts and bronze bushes etc are a bit of an over kill for most scale model ships. In reality most models do not spend hours on end sailing around at high speeds so softer or cheaper materials can often be used instead.
I have found that I can achieve acceptable results by constructing my own running gear components with material that is a bit easier to come by. Of course you need the machinery to be able to do this particularly as the models get larger. For smaller models it is a pretty simple task to make the tubes and bearings from various sizes of brass tube soft soldered together.
The links at the top of this page take you to pages that detail how I go about making the various bits of the running gear for my model ships.