Shopnotes #115 (Vol.20) - Ultimate Router jig

Milling
Machine
Patterns
!/2"-DIA.
HOLE
20-TOOTH
FULL-SCALE PATTERN
(6!/8" O.D.)
(NEED ONE)
!/4"-DIA.
HOLE
DRIVE GEAR
FULL-SCALE PATTERN
(3!/4" O.D.)
(NEED ONE)
LOCK GEAR
FULL-SCALE PATTERN
(NEED ONE)
1" -DIA.
HOLE
%/16"-DIA.
HOLE
ShopNotes No. 115 Page 1 of 7 ©2010 August Home Publishing. All rights reserved.

INDEXING WHEEL
FULL-SCALE
LEFT HALF-PATTERN
(NEED 1)
&/16"-DIA.
HOLE
NOTE: USE CENTERLINES
TO ALIGN BOTH INDEXING
WHEEL HALF-PATTERNS TO
FORM A FULL PATTERN
C L
!/4"-DIA.
HOLES
!/2"-DIA.
HOLE
4!/2"-RAD.
ShopNotes No. 115 Page 2 of 7 ©2010 August Home Publishing. All rights reserved.

&/16"-DIA.
HOLE
INDEXING WHEEL
FULL-SCALE
RIGHT HALF-PATTERN
(NEED 1)
NOTE: USE CENTERLINES
TO ALIGN BOTH INDEXING
WHEEL HALF-PATTERNS TO
FORM A FULL PATTERN
C L
!/2"-DIA.
HOLE
!/4"-DIA.
HOLES
4!/2"-RAD.
ShopNotes No. 115 Page 3 of 7 ©2010 August Home Publishing. All rights reserved.

NOTE: USE CENTERLINES
TO ALIGN TWO 30-TOOTH
HALF-PATTERNS TO FORM
A FULL PATTERN
30-TOOTH
FULL-SCALE
HALF-PATTERN
(9" O.D)
(NEED 2)
C L
C L
!/2"-DIA.
HOLE
!/4"-DIA.
HOLE
ShopNotes No. 115 Page 4 of 7 ©2010 August Home Publishing. All rights reserved.

10-TOOTH
FULL-SCALE
PATTERN
(3!/4" O.D.)
(NEED THREE)
!/2"-DIA.
HOLE
NOTE: USE CENTERLINES
TO ALIGN FOUR 40-TOOTH
QUARTER-PATTERNS TO
FORM A FULL PATTERN
40-TOOTH
FULL-SCALE
QUARTER-PATTERN
(11!#/16" O.D.)
(NEED 4)
!/2"-DIA.
HOLE
C L
C L
!/4"-DIA.
HOLE
%/16"-DIA.
HOLE
ShopNotes No. 115 Page 5 of 7 ©2010 August Home Publishing. All rights reserved.

Milling Machine
Gear Setups
The router milling machine allows for six
different gear setups to create spiral patterns
(like flutes and reeds). Depending on the
setup, the gear ratio, and therefore the spacing
of the spirals changes. The direction of
the spiral depends on whether one or two
gears are used to connect the drive gear and
main gears, as you can see in the drawings
below and on the following page.
Each set of drawings below shows the
gear setup and resulting spiral pattern. You
can use the information to determine what
will work best for the type of bit you’re
using. It’s always good idea to try out different
gear setups and bit combinations on
a practice blank to determine the best spacing
and number of spirals.
Over time, you’ll develop a sense for the
number of spirals you can use in a design
depending on the gear ratio and the size of
the bit (or a portion of a bit) you use.
SINGLE
SPIRAL
PATTERN
FOUR
COMPLETE
SPIRAL
PATTERNS
{ Spiral Pattern. Each specific gear setup results in a particular
spiral spacing (left example). The indexing wheel ensures that spirals are
evenly spaced for a consistent look once they’re complete (right example).
10-20
GEAR
INSIDE END VIEW
A
1-8 GEAR
RATIO
1%/8
OUTSIDE END VIEW
10-30
GEAR
B
1-12 GEAR
RATIO
2#/8
ShopNotes No. 115 Page 6 of 7 ©2010 August Home Publishing. All rights reserved.

10-40
GEAR
INSIDE END VIEW
C
1-16 GEAR
RATIO
3#/16
OUTSIDE END VIEW
10-20
GEAR
10-30
GEAR
3
1-24 GEAR
RATIO
D
4!#/16
10-20
GEAR
10-40
GEAR
2
1-32 GEAR
RATIO
D
6#/8
10-30
GEAR
10-40
GEAR
1
1-48 GEAR
RATIO
D
9%/8
ShopNotes No. 115 Page 7 of 7 ©2010 August Home Publishing. All rights reserved.