Brass is a very malleable alloy that can be used in a wide variety of projects. For example, a round brass tube works especially well for drive shafts that can be used in RC ships or workboats.
For the assembly of a custom drive shaft with brass tubing, look over the hole of the propeller and measure the diameter of the drive shaft. The new drive shaft requires assembling three tubes of different sizes. You need to get the drive shaft diameter and add two more sizes; the bigger one will be the shaft housing.
There must be a link between the main shaft and the housing. You need half-inch-long sleeves or spacers at both ends of the housing to hold back the shaft as these expand from the heat and friction. They need to be one size smaller than the housing so they can telescope inside it for soldering.
Insert the larger brass tube into the drive shaft with the sleeves soldered in on both ends. The housing itself should be greased at first, but drill a small hole just behind one of the sleeves. As you spin the drive shaft on a bench vise with a DC motor and battery, you will insert more grease into the hole to further lubricate it. Make sure to rough-sand the parts of the housing where it comes into the hull, where you’ll use heavy-set epoxy glue to ensure that the main assembly will not vibrate under the strain.