July 2019 33›
Hydraulic Press
A Hydraulic Press
James Perry describes how to make a workshop press around
a hydraulic jack. Part 2.
T
his meant that when the V die
was clamped up for drilling, the
four fixing holes could be spotted
through for accurate positioning in the
die. See photo 20. I believe in maximum
screw length retention, particularly where
shock loading can be expected. The
tapping holes in the die had to be drilled
as deep as reasonably possible, without
breaking through the other side. Aft er they
were drilled the base plate and die were
separated and the two inner base plate
holes were opened up to 5/16” diameter
and countersunk on the underside to
accept the fi xing screws. With two large
and cumbersome clamps holding the die
and base plate together I found it was
better to complete the two inner fi xing
holes entirely. Fixed with the inner screws,
it enabled me to dispense with the clamps.
Of course, only aft er all tapping holes were
complete could I open up the remaining
two fi xing holes to 5/16” dia. It then just
remained for the two end holes to be
opened up to 3/8” to accept the guide rods
The ½” dia guide rods had a 12mm long
section machined down to 9mm. This
meant the resulting shoulder ensured they
would stand upright in the base plate.
The 9mm dia section also had a weld prep
chamfer machined on it. The top ends of
the rods were drilled and tapped M6 to fi x
the end caps. They were duly welded into
the base plate and the welds ground fl ush
on the underside of the plate.
Photograph 21 shows the die and
guide rods ready for the base plate.
A small digression here. I’m a magpie
where supplies of good materials are
available. Never throw a printer away
without scavenging for materials, inparticular the beautifully polished and
machinable rod they contain. Whilst they
are made virtually all over the world, they
keep to their USA origins. Everything
seems to remain imperial (well USA
imperial anyway), hence my use here of
imperial rod.
The Blade is made from 75mm x 12mm
BMS. The business edge has a 90 degree
angle to match the Die. It follows Alan
Hearsum’s style in having a 2mm flat at
the apex rather than a sharp point. On the
heavier bends a sharp apex wouldn’t last
long. The pressure pad has a deep slot toaccommodate the Blade and to ensure a
very strong weld. Photograph 22 shows
it ready for machining.
Photograph 23 shows the tooling
assembled in the press. An extender has
been added between the Pressure pin
and the Tooling. I found that in use, the
narrow 12mm thick blade caused the fold
to close to less than 90 degrees when
applying pressure to get the sharpest
fold. It meant that for the heavier gauge
metal I had to accept curved folds with
an inner radius of perhaps 6-8mm rather
than tight 90 degree bends. In addition,20
21 22