INCRA Twin Linear - Manual (Page 12)

Zero Clearance Subfence
The large fence offset range offered by the TWIN’S dual
carriage design provides an interesting approach to the use
of zero clearance subfences. Typically a zero clearance
subfence is a long piece of wood with the profile of a
particular router bit band sawn into the face. When attached
to the router table fence and moved into position the router
bit nestles into the cutout. This close fit around the router bit
provides both additional support and tearout protection for
the boards to be cut. By offsetting the TWIN’S infeed fence
an amount equal to the thickness of the subfence you can
quickly produce an infeed only subfence that offers perfect
tearout control and infeed support. Here’s how:
Prepare subfence blank
Begin with a smooth flat piece of wood 3 / 4 " thick x 3"
wide x 16" long. I prefer medium density fiberboard. It’s
inexpensive and usually pretty flat. I don’t recommend
plywood because it splinters too easily. Drill and
counterbore the subfence using the dimensions shown in
Fig. 21.
Adjust th fence gap
Install the cutter in your router and set the fence gap.
(see Gap Adjustment section above) so that the fence ends
are no closer than
1 / 8 " from the cutter.
Offset infeed fence
Move the fence away from the cutter and offset the
infeed fence about 3 / 4 " behind the outfeed fence (Fig. 22) on
the next page. Note: An infeed offset of 3 / 4 " will move the
black adjustment knob beyond its working range, so instead of
turning the knob as described in Step 4 on page 10, just slide
the infeed carriage back by hand.
Gap Adjustment
Follow these steps to adjust the opening between the
infeed and outfeed fences (See Fig. 19)
Caution: When adjusting the fence opening or
gap, never position the aluminum fence ends
closer than
1 / 8 ” from the router bit.
Using the supplied hex tool, loosen the
(4) socket head cap screws that hold the
fences to the fence mounting bracket.
Open or close the fence gap by sliding
each fence to the desired position
Tighten the fence mounting screws
12
2
3
1
See Tip on page 4 for fence mounting
options to consider when adjusting the gap
in the fence.
Fig. 19
Adjusting the fence gap
First:
Loosen (4) socket head cap
screws through access holes
in fence mounting bracket
Second:
Adjust gap
Third:
Tighten fence mounting screws
Fig. 20
Zero clearance subfence on infeed fence
2
3
1
Fig. 21
Subfence dimensions
4"
16"
8"
4"
3"
1 31 / 32 "
3 / 4 "
Hex tool
Access holes
Fence
mounting
bracket
5 / 16 " through hole with
3 / 4 " dia. x 3 / 8 "deep
counterbore