Hi Cic.,

I don't think it's just a case of lifting the jack and platen. The bungee
cords will have to force the jack's column back down into the housing.
This requires considerable effort, which is usually applied by the weight
of a vehicle or other load. I think you would have to experiment to see if
the bungees were strong enough to do this or decide to do it by hand. That
shouldn't be a real problem unless you go in for mass production with a
time and motion programme in force.

All fair points. You could have a separate non-elastic rise mechanism
- a cord on a cam or something - such that you release the bottle jack
and then raise the platen in a separate operation. But this is
starting to get over-complicated IMO.


I don't believe the average jack will work upside down. Whilst making a
small press recently to remove car stub axles I came across the
information that most of the common car type hydraulic jacks will only
work on their side if the handle side of the jack is facing downwards.
This restriction would seem to suggest that they won't work upside down
but it's worth testing individual jacks - under load - to see if they will
do so.

I too strongly suspect they won't work upside down. I'm starting to
think that the original plan of a decent press screw may be the best
way to go ...

Jon N