Roger Hayter wrote:

Yes, that's the sort of thing I was thinking off. You can get them with
just the red and green button and not the added rather gross red one!

Thanks for that. Yes, the massive panic switch is perhaps a tad over the
top for my little Unimat lathe.

On the subject of whether to place a switch in the mains line or the 24V
feed, I've been advised that a switched-mode PSU doesn't like being
frequently switched on and off (as would happen if the operations switch for
the lathe was before the power supply). Would a switch like the ones we're
talking about be equally effective in the 24V supply to the machine?