Today I was faced with having to produce a 10 mm x 18 mm mild steel cylinder. Not having a chop saw or similar I stuck a piece of stock in the chuck of my 8" drill press, improvised a scribe and marked out a circumferential line where the cut was to be made. I made the cut along the line (more or less) with a hacksaw. It was not too bad, but not quite flat and not quite at right angles to the sides.
This is where the problem came.
I do not have a lathe. All I have is a drill press and a 6" disk-4X36 belt sander. I just could not get the cut straightened up. The disk sander has a degree of give in it so pressure causes a variable deviation. The mitre gauge has a minor degree of play. I tried switching to the belt sander in a vertical position and the result was even worse. In any case one does not relish getting one's fingers that close to abrasive material at high speed.
In the end, this is what I did: I clamped the cylinder in the drill press chuck so that about 6 mm stuck out. I found an old file which was quite big and flat. I clamped it to the drill press table. I slathered it with a cutting compound, turned the drill press to 1500 rpm and lowered away. It took quite some time but the result was really quite good.
Unfortunately I slightly spoiled the result through impatience: The file was not cutting fast enough and I thought I would try to wrap it in coarse sand paper. With the most stock removal happening at the periphery and the slight "give" of the sand paper the cylinder is ever so slightly convex rather than perfectly flat.
I am not sure how many safety commandments I violated but it got the job done.
Does anyone have any suggestions how to tackle a similar problem given limited resources and definite lack of manual skills?