34 http://www.model-engineer.co.uk Model Engineers’ Workshop
the 2mm wide flat on the face of the blade
imprinted itself on the inside of the fold. If
anything, both of these effects had their
advantages and looked good on finished
jobs.
However, it did raise the question.
What about the times when I particularly
wanted square corners? Since this was
almost always when folding thinner plate,
the use of a blade without a flat on the
pressure point was quite workable. It also
meant that the Die would need a narrower
V slot to accept model sized folds.
This was achieved by adding adaptors
to the existing Blade and Die. The
addition to the blade is shown in photo
24 and that to the Die in photo 25 They
were both cut out of 25mm square bar.
Each was cut initially to about 400mm
long and allowed a sacrificial 50mm each
end. This allowed the workpieces resting
upon V blocks at each end to be clamped
to the milling table outside of the required
working length.
Photograph 1 showed the tooling with
the adaptors fitted mounted in the press.
Cheek plates 100mm apart are shown,
between which various tooling assemblies
are mounted.
The following show a couple of light
weight folding jobs. Photographs 26
and 27 are rather obviously an ash pan
for a wood burner. Photograph 28 came
about because the CO objected to the
noisy clatter in high winds and decided
to remedy the situation with sticky tape.
My protests were pointless. However, it
was a good excuse for me to play with the
Folder, hence photo 29.
Garden Gate and Arch Curves
I have never liked the “Meccano” gates
made with fl imsy fl ats which seem to be the
norm these days. My aim was to produce
curves and spirals cold, which are usually
only ever done in a forge. Photograph
30 shows the tooling I produced to make
the bends. The tool is 25mm BMS round
and the die sides are 30mm dia. They are
mounted on 12mm thick plate 100mm wide
by 130mm long. The confi ning cheek plates
are shown as usual bolted to the anvil plate
100mm apart.
The curves are produced by taking small
bites every, say, 30 mm along the metal.
Whilst this suggests a series of little fl ats
between the bites, in practise the result
is indistinguisable from a true curve. The
distance between bites depends upon the
size of the curve being produced.
The two “horns” of the tool suggested to
me originally that using both at the same
time would enable me to produce matching
pairs of spirals. In the event, I discovered
that I would need two pairs of hands. An
electric pump and foot pedals would have
been the answer, but the scope of the job
would have ballooned out of all proportion.23
24
25