Hi Cic,

That one looks quite good, although the return springs (bungee cords)
might not give a smooth return with the possibility of the top plate
tilting and jamming. Nonetheless, it's a clever and simple way of doing
the job - possibly a bit dangerous as those cords will need to be under
considerable tension to retract the column of a bottle jack.

The smoothness of the return doesn't bother me too much. When you
say ... 'retract the column'... I guess you're simply referring to the
bungees having to lift the combined weight of the Jack + platen? Yes,
this is something I wondered about.

Is it possible to use a bottle jack upside down? if so, you could fix
it to the top of the frame, pointing downwards, and the bungees would
only have to lift the platen, and the bit of the bottle jack that has
just been 'released' ... whatever that's called.

J