Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Engineering Techniques and Materials. => Topic started by: Hurric123 on February 05, 2019, 09:42:19 am

Title: Joining a prop to a flexi inner shaft
Post by: Hurric123 on February 05, 2019, 09:42:19 am

Hi, I have inherited a nice wooden cabin cruiser overall length 50cm. Its beautifully built and worth getting back on the water.
The brass prop shaft is curved and the inner shaft and rudder are missing.
The only flexi I can find to fit inside the shaft is 2mm diameter. I obtained this from Venhill who make motorcycle control cables.
Incidentally they do some handy parts on their website such as cable sealing bellows.
My problem is how do I join 2mm flexi to a propeller? there doesn't seem to be a fitting available .
I am not a great machinist but maybe I need to drill out a short lenght of brass rod to 2mm, solder the flexi into it and drill out the other end for a short 4mm stud and solder that in?

Title: Re: Joining a prop to a flexi inner shaft
Post by: Klunk on February 05, 2019, 10:03:45 pm

look on here
http://www.prestwich.ndirect.co.uk/surfacedrive.htm
https://www.modelmarinesupplies.co.uk/products.php?cat=85
might be something on there

Title: Re: Joining a prop to a flexi inner shaft
Post by: Andyn on February 06, 2019, 01:53:13 am

Can we get a look at this flex? Neither 2mm nor motorcycle control cable sounds at all suitable. The smallest flex I've seen available is .098 with a 1/8" stub, this would be for very low power applications. Brass would not be suitable as a stub shaft

Below is what a typical flex looks like. Flex goes into steel stub shaft and is either braized, welded or in some applications epoxied.


(https://www.offshoreelectrics.com/prodimages/ose-1085.JPG)