ENLARGING THE 3MM HOLES TO 20MM
9
Figure 19
The 20mm Cutter (Figure 18)
The 20mm Guide Block (Figure 19)
The 20mm Cutter has a 3mm spike at its tip. This spike has
no cutting action and so the cutter can only be used where a
3mm hole has previously been drilled through the material of
the bench top. It is recommended that there is no support
directly under the place where the 20mm cutter will emerge
as this can damage the cutter and reduce the quality of the
exit hole.
Please note
, to eliminate breakout in certain materials, we
recommend you should make a scribe cut using the 20mm
cutter on the underside before drilling from the face side, this
is done using the 3mm spike as a guide.
The 20mm holes are created using the 20mm Guide Block,
the special 20mm cutter and either the 3mm Guide Pins or
the Parf Locator Dogs.
The 20mm Guide Block is secured to the bench top being
created with either the 3mm Pins or the Parf Locator Dogs.
The 20mm Cutter can be fitted in two positions, shown in
Figure 15, which indicates which fixing method is used.
In order to position the 20mm Guide Block, insert the 20mm
Cutter and use its spike to locate the 3mm hole that is to be
enlarged. Then secure the Block with either the 3mm Pins or
Parf Locator Dogs.
It may not be necessary to enlarge all of the 3mm holes and
it is worth thinking about the minimum number required to
create your bench top or track saw cutting station. When
using the Parf Guide System for the first time you may prefer
to clamp the 20mm Guide Block but as long as the 20mm
Guide Block is firmly held to the bench by Pins or Dogs then
no clamps will be required.
NOTE:
The 20mm TCT Drill Cutter is supplied with a stop collar
to avoid it dropping through to the floor at the end of a cut
after it is released from the drill.
NOTE:
It is recommended that a pecking action is used with
both the 3mm Drill and the 20mm Cutter. Cut a quarter of the
way through and withdraw the drill slightly, drill the next
quarter and withdraw and so on.
Figure 18