T4 - USA
-13-
Guide bush
fitted to
router.
E
d
D
Template
FORMULA
(D-d)
E = 2
Using the Guide Bush
The 5/8” guide bush (1), or the adapter plate for
screw on style bushes, is fastened to the router’s
base from beneath using the two M5
countersunk machine screws (2) supplied.
Routing with a Template
The guide bush is used in conjunction with a
template when the routing operation is repetitive
or the workpiece is complex in shape. The
template is fixed to the upper surface of the
workpiece. A bit is chosen with a diameter
which will pass through the centre of the bush
leaving enough clearance. The bit can be
straight or shaped. The router can then be
guided around the template so that the shape of
the template will be replicated.
Making the Template
The template is cut from 1/4” MDF, plywood or
plastic to the shape required. The guide bush
offset needs to be allowed for when calculating
the shape of the template. The template must
be smaller by an amount equal to the difference
between the ‘outer edge of the guide ring’ and
the ‘outer edge of the bit’. See below for the
offset calculation. The edge of the template must
be free of imperfections as these will be
replicated in the final workpiece.
Making a Router Stand Block
When using a guide bush a useful aid is a router
stand block. This is simply a piece of scrap
timber with a hole large enough to take the
protruding guide bush and bit. This will allow the
router to stand up safely between operations.
Calculations for template offset
Template
Template
guide bush
Workpiece
Guide
bush ring
Cutter
Using a template
to rout an edge
straight.
Alternatively it can
be used for cutting
shapes or making
panelling grooves.
2
1
In some instances the bit may project
below the guide bush, so ensure a
router stand block is used.
When using a T4 with a Hinge Jig a
universal sub-base Ref. UNIBASE is
recommended.
MANU-T4-USA v2.0 30/8/07 1:09 pm Page 13