PM Research 1880s steam drilling engine: Philip Hill builds an American engine kit - PART 2

摘要

Next to prepare were the crankshaft bearing surfaces. The horizontal centres are deduced from the major centreline, but in the vertical plane, the axis is at 45 degrees to the centre height line. The actual vertical location of the crank centre occurs where the principal centreline coincides with the bearing seat. To obtain this point, I reset the angle plate diagonally on the table, and shimmed from this up to the required 45 degree angle. By end milling I was able to cut downwards until I reached the punched horizontal location mark of the required crank centreline (photos 7 and 8).