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point to the centre of the slot. The slot was
cut with a 1/4” slot drill.
Photograph 12 shows the basic setup of
the protractor on the machine. This photo
shows the chop-saw locked in the raised
position, where the on/off switch on my
machine can be accessed. The advantage
of the protractor plate being locked in the
raised position, creates extra safety when
starting the motor.
It is perfectly practical to dispense
with the protractor, but it has various
advantages, and on my machine, locking
it at the bottom position, allows the rear
fence to lock between the swivel plate
and the angle grinder, thus preventing the
grinder from traversing the horizontal slide
rail when transporting the machine.
Readers will note from photo 12 that
the rear fence is simply a length of 25mm
angle iron bolted to the baseplate. As the
cutting disc is in front of the swivel point of
the angle grinder, it is imperative that the
rear end of the slide rail is set back from the
baseboard for the grinder to be able to cut
right through the rear fence.
The knob to lock the protractor was a
simple turning job on the lathe and knurled
to a diamond form. However, the centre
was tapped M6 and a long M6 cap head
setscrew was countersunk into the knob
in order that a hexagon (Allen) key may be
used by those with arthritic hands, photo
13. It proved to be unnecessary in my case,
but is a good alternative to using security
levers, and I prefer the appearance. The
side of the sliding housing was drilled
and tapped M6, and an M6 Nyloc nut
was epoxied to the inside of the housing
to reinforce the aluminium thread in the
housing. A captive washer was also epoxied
between the protractor and the housing to
give appropriate clearance.The Arguments for or Against a
Mitre Fence
My rescued saw table already had a slot
for a sliding mitre fence, so I used this to
take a Picador mitre fence, which I already
had for my belt sander. This is shown in
photo 14. However, there is no need for
the mitre guide to be able to slide. A static
mitre fence is just as eff ective, because
the actual cutting blade can slide forward
and backward. I fi nd that I usually make
an angled cut with the sliding mitre fence
pressed back against the static back fence.
A static mitre fence would be much easier
to make than a sliding fence.The Advantages of a
Longitudinal Fence
I fi nd that a longitudinal fence i.e. a normal
circular saw type of fence is a useful
addition to the metal sliding chop-saw.
This is illustrated in photo 16. with the
fence situated to the right of the saw blade.
This would probably be the normal use ofthe fence, but the fence could be just as
easily used on the left side of the blade.
Photograph 14 shows the fence being used
in this way. It is helpful to use the fence to
the left , when cutting more than one part
to exactly the same length.
The fence “T” bar sits on the top of a
straight edge which is bolted parallel to
the front of the baseplate. The T-bar has
a groove milled into it so that it is a tight
sliding fi t onto the front straight edge.
Of Course, extreme care must be taken
to see that, when in situ, the fence must
be absolutely parallel to the travel of the
cutting blade.General Comments
I fi nd the machine a pleasure to use. If the
cutting feel is to be comfortable and smooth,
I believe that it is necessary for both the
sliding and the swivel mechanisms to be
perfectly free of play, and this is the reason
that I chose to use ball bearings for the slide
and PTFE coated bushes for the swivel.
I use 1mm wide cutting discs, which cost
less than £1 each at my local tool shop and
they seem to last a long time. I am still using
my fi rst one!
Anyone making a similar item will be
using parts that they have around or can
be cheaply available, so my instructions
are intended as a list of ideas as to how to
create your own device. I hope that readers
fi nd this to be useful. ■13 14
15 16
Protractor locking mechanism Sliding mitre fence
Optional longitudinal fence Fence clamping mechanism