MILLING THE COLUMNS for THE BOLTON 9 MARINE ENGINE
90% setup time, 10% machining.
The columns are tapered on all faces, so are difficult to hold, and difficult to measure.
I did a CAD drawing, to measure the taper angles, and to calculate some extra dimensions.
Then, in order to hold the castings in the milling vice, I made some accurate wedges at the appropriate angles (3 and 12 degrees) in wood and aluminium.
I actually progressed a bit further than the photos show, even roughing out the condensing tank.