BANDSAW OPERATIONS - OD1646 - LESSON 1/TASK 1
(2) Preparing the Blade.
First, the saw blade must be cut to length.
Using a blade shear will ensure that the blade ends are flat, square, and
smooth. If snips have been used to cut the blade, the ends must be squared
before welding. This is done by grinding the ends of the blade. Both ends
of the saw blade should be ground in one operation.
Holding the ends so
that the teeth point in opposite directions during grinding will ensure that
the two ends will match perfectly when turned over, regardless of the angle
of grinding. Then blade ends must then be carefully cleaned. The part of
each blade that comes into contact with the welder jaws must be free of all
dirt or oil. Any dirt or oil on the blade or welder jaws will prevent good
electrical contact.
(3) Preparing the Welder. First, clean the welder jaws. On the model
2612-1M bandsaw machine, the integral butt welder has a jaw upset force
selector (refer to figure 24 on the previous page), located directly above
the stationary jaw.
The jaw upset force selector provides a variable
control since wider saw bands need greater upsetting force between the jaws
than narrow bands, and since too much force on small bands will cause
climbing or overlapping.
In preparing to make a weld, the jaw upsetting
force selector control should be set to the correct position for the width
of the saw blade being welded.
(4) Saw Blade Alignment Before Welding. Before making the weld, the saw
blade ends must be aligned so that the blade will be straight after welding.
If internal sawing is to be done, the blade is inserted through the starting
hole in the work. Then the ends of the saw blade are brought to the welder
to be clamped into the jaws. Align the blade using these steps:
(a) Insert the saw blade between the jaws with the back of the blade
against the back of the jaws, lining up the blade so that it will be
straight after welding.
(b) The blade ends should meet in the center of the
jaw gap without any
offset either in thickness or across the width (figure
25 on the following
page).
If the ends are clamped in an offset manner,
an overlapping weld
will result. This type of weld will have to be ground
too much, resulting
in a weak weld.
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