routing
innovations
Jack Cox explains a few of the unique
routing techniques possible when using
his Pivot Frame Jig.
he Pivot Frame jig was
originally designed to cut
circular rebates for fitting
small mirrors into frames. However, it
has proved to be a highly versatile
routing jig, with uses way beyond
those originally envisaged. The
following examples explain a few of
the many applications devised so far doubtless there will be many more in
the future.
T
A retired electronics engineer,
Jack has acquired an enviable
reputation for both his medal
winning lathework and the
intricate decorative work that
he produces on his innovative
Pivot Frame Jig.
Beam trammel
Conversion to a standard beam
trammel mode permits the jig to
make its own circular disc template
by swinging it about the detachable
pivot supplied with the jig.
by Jack Cox
circular disc template can be used.
This smaller disc is drilled to take a
central bolt, enabling it to slide along
a slot cut through the primary disc or
worktop allowing the workpiece to
be offset from the pivot point or
Mini-pivot frame jig
operations
The Pivot frame jig is used for
creating an artificial centre point,
allowing the router to be rotated
around a circular disc template of
MDF or plywood. The radius of the
circle and the cutting radius is altered
by changing the position of
the router along its rods. In
this way, the problem of the
pivot point disappearing
beneath the base of the
router is eliminated.
The circular disc template can also be
drilled with a series of equally spaced
holes on its outer rim. These are
engaged by a small rod or indexing
pin, mounted in a ‘stop block’.
Twenty four holes enable a full
circle to be accurately divided into
combinations of equal segments.
Alternatively a smaller secondary
primary disc centre. It can then be
rotated in steps, determined by
the indexing holes around the
rim of the secondary disc. Either
of these two methods can be cut to
both internal and external scalloped
designs.
August 1998