Model Engineers’ Workshop – July 2019

July 2019 35

›

Hydraulic Press

When doing any bending with the

press it was important not to over-bend.

Experience showed that less is always

better than too much. Restraightening

was always an unwanted chore and in the

early stages it often meant scrap metal.

I had a salutary lesson on the

importance of proper weld penetration.

During an initial trial. I was bending 30mm

x 5mm. It proved to be well within the

capabilities of the jack, so I kept pumping

for maximum shape, pushing the tool

down between the die sides. With a shot

like a gun one side of the die flew off in a

very dangerous manner. Photograph 31

shows the result and the very poor weld

I had on it. My welds definitely had more

attention after that!

I found that initially I still ended up with

a small flat at the start of each curve, so

this end was hacksawed off each time.

Later on, I found that placing a section

of 20 x 5mm flat against one of the Die

rounds, I was able to form a full curve

from the outset.

Photograph 32 shows some of the

curled flats and photo 33 a gate they

formed part of.

I’ve made a number of garden arches

out of half inch rebar by pulling the metal

around in the vice. After shoulder damage

I can no longer do it this way. The press

now takes all the hard work out of it.

Incidentally, the ridged pattern on Rebar

provides a brilliant surface for climbing

plants. Photograph 34 shows typical

results. The large radii were achieved by

continually checking the result against a

template. I found after a bit of practise

that a bite every 50mm or so produced

satisfying results. I made sure that all

welds were continuous, which, coupled

with heavy coats of Hammerite keeps the

rust out for a good while.

Broaching Keyways

Again, in the past, I’ve had to cut keyways

the hard way usually by sawing and fi ling.

I thought the press would provide an ideal

opportunity to produce machine quality

keyways.

My method however was not a success.

Nevertheless, it’s worth a brief explanation

I made sure that all the

welds were continuous,

which, coupled

with heavy coats of

Hammerite keeps the

rust out for a good while

26

27