[ARC5] Arc-5 screw removal

[Neil]

The consensus seems to be that, other than using a dentist's pick
to try to rotate the broken-off section out of the threads, the
operation requires precision drilling and is beyond the ability of
the average guy who has only a cordless drill.

I had been thinking along the following lines:

1. drill a small pilot hole in the centre of the shaft
2. heat or cool (I'm not sure which) the entire item to take advantage
    of the different coefficients of expansion of aluminium and brass
3. drill at very low speed into the pilot hole with a blunted bit whose
    diameter is somewhat larger than the pilot hole and somewhat less
    than the minimum thread diameter.

The idea being that the blunted bit would bind when entering the
pilot hole and slowly rotate the brass screw out.
I don't have the workshop to carry out the procedure. Does it have
any merit?

73 de Neil ZL1ANM