Building an Oscillating Engine for my first engine

Help Support HMEM:


Well-Known Member
HMEM Supporter
Apr 2, 2020
Reaction score
3 Ettrick grove, Sunderland , Tyne & Wear, SR 48
For a simple bored cylinder, a reamer often achieves the accuracy required. But I DON'T use my lathe for parallel and round bores by holding the work-piece in the chuck, as it is not so accurate a process. My first couple of engines were made this way, on different old lathes, but I generated tapered bores due the the lathe alignment inaccuracy. I now bore with the mill-drill - mostly: as this means the tool describes a true circle, which then passes down the axis of the bore giving a true cylinder. On the lathe, it means the boring tool is mounted in the chuck/fixture in the main shaft - preferably between centres, and the work-piece is mounted on a fixture on the traverse (remove the tool post to mount a suitable bracket). Then the work-piece is traversed over the boring bar using the main carriage.
But this often means more work than using the mill-drill (making mounting brackets and aligning the part to DTIs set in the chuck or between centres), and I am lazy, so use the mill-drill as a boring machine. Perfect bores every time, with no taper, nor circular error.
And this is how true bores are made in industry.
It helps to have a good mill-drill... but my first bore was "corrected" this way using a simple pedestal drill.

Latest posts