Ian White wrote:


But I can't find any source of *small* bullseye levels for the rear end
of the drill. The ones in the usual electromechanical component
catalogues are too big. Any ideas, please?

I assume that you're wanting to cater for the situation where you're
drilling vertically downwards.

I needed to do that and first of all needed to mark the end of the
drill, as though the centre of the shaft had come through and out of the
back. There are several ways it could be done, but tried to improvised a
way with a plumb bob suspended over my workshop vice. I marked the vice
where it touched, clamped a 1/2 round bar into the vice and then ensure
that the upper end of the bar was aligned with the plumb bob, but
unfortunately the vice couldn't be persuaded to hold the bar exactly
vertically.

So I clamped the bar horizontally and used the spot from an IR
thermometer to shine along the axis of the rod, closed the drill chuck
onto the round bar and marked the other end where the spot touched.

Then I marked the point where I wanted to drill and arranged the plumb
line over that spot, with the string passing through a hole in a bit of
scrap metal clamped two or three feet above it. It was then a simple
matter to raise the plumb bob appropropiately and use it to check that
the drill was absolutely level.