On 02/02/2019 06:36, Mike Spencer wrote:
David Billington writes:

I've not seen a powered one like that but it's basically a fly press as
others have mentioned. For manual operation they're quite nice as you
get a feel for the energy input required to do the job so you adjust
accordingly. I have one and they're quite common in the UK. The pic
posted of a bunch of them in Texas looks a lot like Norton or Sweeney &
Blocksidge but I expect they were made in the US as well.
The Brit blacksmiths love fly presses and Blacker hammers, both of
which are like hen's teeth in Leftpondia. Another use was
architectural ceramics: clay, damp but not wet, was put into a
mould/form and rammed with a flypress, then fired. Apparently a way
to force the items to retain dimension, not so easy with wet clay.

AFAIK, some flypresses have a simple screw but the one I had a close
look at Britain had a two-pitch screw, ingenious and very effective.

Details, photo and diagram he

http://home.tallships.ca/mspencer/nut.html

Retired but I'd still love to have one to mess about with.

Some other smithing oddments if yer interested:

http://home.tallships.ca/mspencer/tools.html


My Sweeney & Blocksidge has a 2 pitch screw but that is quite normal for
many makes. The coarse thread is what applies the force and the fine
thread is at the upper end of the screw and is what the stop collar fits
to to allow fine adjustment of the ram travel.