INCRA Ultra 24 - Manual (Page 9)

groove cut in Step 3. There should be a small gap between
the edge of the bit and one side of the groove. See Fig. 16.
Now all that is needed is to micro adjust the fence position
so that with the board against the fence, the bit is in the center
of the groove. To do this, simply “unlock” the carriage clamp
and press the micro adjust lever down, then turn the micro
adjusting knob until there appears to be an equal gap on both
sides of the bit. See Fig. 17. “Lock” the carriage clamp back
in place. You have now successfully found the center of the
3
3 /
4
" wide board with your router bit. If you were setting up for
joint making on this width of stock, you would now slide a
joinery template from the optional Master Template Library into
one of the auxiliary scale slots. By positioning the template to
place the preselected “center cut” mark directly under the
hairline cursor, you would be ready to cut a perfectly centered
joint. In fact, if you’ll turn now to page 12, you’ll learn how to
use the center you’ve just found to produce a box joint and a
half blind dovetail on 3
3 /
4
" wide stock.
After centering on the 3 3 /
4
" wide board as
described above, slide the extra 1 /
32
" “floating”
scale to position the 1 7 /
8
" mark directly under the
hairline cursor.* Now the center of any board can be
found quickly by using this scale.
Example: If you want to locate the bit in the center of a
4" wide board, simply “unlock” the carriage clamp and
move the carriage to position the 2" mark on this scale
directly under the hairline cursor (4"
÷
2 = 2"). Now lock
the carriage in place. You might still want to make the
test cuts described in Step 3 above since your actual
stock width might be slightly more or less than a true 4"
measurement.
*On some smaller router tables you may find the 1
7 /
8
"
mark will not reach the hairline cursor. To remedy this,
simply move the hairline cursor to the rear of the base.
See Fig. 12 on page 8.
“Centering” the bit on your
workpiece
Making a series of cuts relative to the center rather than the
edge of the workpiece is often quite useful when producing
symmetrical pieces. “Centering” is always used when setting
up your INCRA JIG ULTRA for joint making. Let’s use a hands
on step-by-step approach to understanding this important
setup technique. Follow along and you’ll learn how to “center”
a
3 /
8
" straight bit on a piece of stock 3 3 /
4
" wide.
Begin by cutting a piece of 3 /
4
" thick stock to 3 3 /
4
" wide by 6"
long. Install a 3 /
8
" straight bit and set the depth of cut to 3 /
8
".
Align board with bit
Mark the center of the board’s width on one end and
place the board face down on the router table with the
center of the board aligned with the approximate center of the
bit. See Fig. 13.
Set initial fence position
“Unlock” the carriage clamp and slide the fence up to
the edge of the board then “lock” the carriage clamp
back in place. See Fig. 14. Make sure the center mark on the
board is still aligned with the approximate center of the bit.
Rout the test groove
Turn on the router and, using a good rubber soled
push block, cut a groove along the entire length of the
board. See Fig. 15. Now turn the stock end-for-end with the
groove still face down, and make a second pass over the bit.
This second pass should widen the groove slightly (unless you
are already perfectly centered!) Make sure you have turned
the stock end for end before making the second pass. (This
places the center mark at the back of the board.)
Fine tune the fence position
With the router unplugged, turn the bit to its widest cut
angle when viewed from the infeed side of the table.
Place the board against the fence with the bit just inside the
1
2
4
FIG. 13
Align board with bit
FIG. 14
Set initial fence position
Third:
"Lock" carriage clamp back in place
FIG. 15
Rout test groove
Center of
board aligned with
approximate center of bit
FIG. 16
Small gap between
bit and one side of
groove
FIG. 17
Micro adjust fence
to place bit in the
middle of groove
Equal gap on
both sides of bit
Small gap
Mark
center
of board First:
"Unlock"
carriage clamp
Second:
Slide fence up to
edge of board
Second:
Turn stock end-for-end
and make a second
pass over the bit
First:
Rout a groove
along entire
length of
stock
3
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