On Mon, 23 Jan 2006 15:13:25 GMT, "John Riley"
wrote:

Could someone point me to some information about what metals I could use for
king pin bearings on a small, electric-motor-assisted, adult trike I'm
planning to build?
I was thinking of a tubular, square, thickwalled aluminum axle, and two mild
steel plates bolted top and bottom to each end of this with holes bored top
and bottom and a thick aluminium rod turned to fit into the holes of these
plates (trunnions?) and then be drilled and tapped at the correct angles for
the M12 HT steel bolts for stub axles.
In other words, with good lubrication, is aluminium rod OK in steel bushes?
There will be little rotational motion, and with a large bearing surface,
shock loads should be no bother.


Buy a bicycle for $20 from a garage sale (perhaps carboot sale, given
your spelling of "aluminium"), cut it up and use the headset and
ball bearings it contains. It will be a lot easier to steer if it
has good geometry and good bearings.