Today I managed to drill, then tap the oil filler holes on both cylinder blocks of the Seal engines.  The set up time for any machining  task is normally much longer that the metal removal and today's task was a fine example of the little extra effort in making another engine.

The first job was to set the adjustable angle vice up on the milling machine. The plans call for the oil dipstick filler hole to be at an angle of 20 deg to the engine blocks head. The way I set this angle was to use the digital angle meter I have. A much valued tool and a recommended addition to any workshop. It was first zeroed on the milling table then with the casting standing on a pair of parallels, the meter placed on its top and the vice adjusted until the correct reading was seen.

I decided that I would reduce the speed of the drill and use three different sized drills before starting the tap. This method ensured that the threads would be cut in line with the drilling. However I find it easier to move  the casting to the bench and finish the thread, BUT only after it has been started in the same position as the drilling.

Hopefully here are a few pictures that will make the text clearer.......