Making a Simple Spring
Bender
Having reached the stage of needing the 2.5mm piano wire (spring wire) bent
to form a spring, I set about making a simple wire bender.
The progression of pictures shows what lies behind the simple machine.
Basically a piece of 1"x1" angle steel, about 6" long, which was drilled
1/4" and countersunk a little, to take the reduced end of the 1/2" former,
around which the spring is formed. The lower end of the 1/2" former was machined
to 1/4" and cut off, so that it just protruded below the angle iron, and
then it was riveted over.
You will see in the pictures that there are many holes drilled in the angle
iron, as I did not know where I needed to locate the holder of the spring
steel being formed. The experience of making the first spring shows that
the best position to hold the spring steel is near to the forming post.
The clamp to hold the wire is made from a piece of 1/4" round bar. This was
cross drilled and filed off so that there was little of the bar showing above
the spring steel being formed. It passes through the angle iron and
then is locked into place underneath by threading the bar 1/4" BSW and tapping
a piece of brass bar to match. It would probably
be much easier to make this clamp out of an ordinary nut and bolt, which
wouldn't require any threading and tapping - MW.
NOTE: The spring steel being formed must be held securely in place,
else it will tend to creep along the angle iron and not be well formed around
the forming post.
The forming handle is merely a flat piece of bar about 9"x1"x3/16" long,
drilled out to fit the 1/2" forming post and a 1/4" section of bar riveted
on using the same method of reducing the bar size and using an appropriate
size hole before riveting in. The bar only projects 1/4" below the
handle, so fouling the clamped section of spring should not occur when making
the second turn etc.
All the bends were made using this simple machine, with the angle iron held
in a suitable vice. To ensure that the holder will release the bent
work piece, the hole in the clamp needs to be about 25% bigger than the material
being bent.
When making the central 2 turns, the spring steel being formed must rise
up and make the second turn around the post and above the first turn and
to achieve this the turning handle must also rise up with the spring steel!!!!
I have set the two arms of the spring about right angles to each other, and
early trials seem to shows this to be very promising. After I had made
the spring I noticed wear on the pin on the forming handle, indicating the
great force needed to form the spring steel. If I were going to be
making several springs then I would use a hardened material for this part.
WARNING: The utmost care must be used when forming the
spring. Allowing the handle to slip off the material being formed must
be guarded against by the use of even and controlled pressure. Being
able to stop the bending immediately is essential. As I have no control
over how you use these ideas, no responsibility can be accepted for any accident
or injury howsoever caused by following these ideas. Suffice to say
that I have safely made the necessary spring using the machine described.
You are advised to wear suitable gloves and safety goggles. |