Leigh D4R Pro User manual

For the
Leigh D4R Pro Dovetail Jig
DEDICATED CUSTOMER SUPPORT
1-800-663-8932

CONTENTS AND STANDARDS
ii
D4R Pro User Guide
Contents and Standards........................................................ii
Chapter 1 Jig Assembly, Mounting, and Using The Clamps .................1
Chapter 2 Adjusting the Finger Assembly.............................................7
Chapter 3 How Routers with Guidebushes Work.................................9
Chapter 4 Basic Jig Functions and Scale Modes ..................................11
Chapter 5 Using Your Jig Safely ...........................................................13
Chapter 6 Wood Preparation ...............................................................15
Chapter 7 Router Preparation ..............................................................17
Chapter 8 Through Dovetails ...............................................................19
Chapter 9 Large and Small Through Dovetails....................................29
Chapter 10 Variably Spaced Half-Blind Dovetails .................................31
Chapter 11 Single Pass Half-Blind Dovetails .........................................39
Chapter 12 Rabbeted Half-Blind Dovetails............................................45
Chapter 13 End-on-End Dovetails..........................................................47
Chapter 14 Asymmetric Dovetails .........................................................49
Chapter 15 Box Joints .............................................................................53
Chapter 16 Sliding Dovetails..................................................................59
Chapter 17 Hints & Tips ..........................................................................65
Appendix I Attaching the Leigh e-Bush to the Router..........................69
Appendix II Bit Selection .........................................................................71
Appendix III Jig Parts ................................................................................79
Appendix IV Customer Support ...............................................................83

iii
CONTENTS AND STANDARDS D4R Pro User Guide
Your New Leigh D4R Pro Dovetail Jig
Congratulations! You now own the world’s most useful and versatile dovetailing tool. The Leigh D4R Pro Dovetail
Jig will help you rout an infinite variety of joints, and all of its major functions are described in detail in this guide.
A very helpful DVD is also included, but the guide is essential reading.
Important! Inches and Millimetres
The D4R Pro jig can be ordered in inch or metric versions.
They're identical except for the calibration scales. This Leigh
English-language user guide shows measurements in both inches
and millimetres, with “inches” first, followed by “millimetres”
in square brackets.
Example:
3⁄4”x 51⁄2”x8” [20x140x200mm]
Do not be concerned if the inch/millimetre equivalents are not
exact. Just use the dimensions which apply to your jig.
To simplify the instructions, most jig illustrations show a jig
considerably shorter than the standard 24"[610mm].
Where finger assembly scales overlay an illustration, the “inches”
scale will be at the top, and “millimetres” scale at the bot-
tom. Only the right hand “active” half of the scales are illustrated.
For clarity, setting positions are indicated with a red line in the
guide only. On the jig, the lines are black.
1
2
We recommend that you first assemble and mount the jig,
carefully following the instructions in the first section of the
guide. Then read the rest of the guide, following along with the
basic functions and principles of operation, before you try to
do any actual joinery routing. By all means, rout a few practice
joints in scrap boards before you use the jig to rout a precious
hardwood work piece!
If you have any questions that are not answered in this guide,
please contact Leigh customer support:
Tel: [phone] email: [email protected]
But remember: “If at first you don’t succeed, read the instruc-
tions!”
*See Appendix IV – Customer Support

CONTENTS AND STANDARDS
iv
D4R Pro User Guide
Glossary of Symbols
To help you understand the instructions and illustrations in this
manual, we have used a number of international symbols, plus
a few special ones of our own.They are all explained below. You
needn’t worry about memorizing these symbols now, because
they are repeated quite frequently in this user guide, and you
will soon get used to them.
The Leigh jig’s guidefinger assembly can be in any one of four
joint modes, depending on what type of joint and which part
of the joint you are routing. Each finger assembly scale has it’s
own mode icon , identifying the joint part being routed.
You will also find the joint mode icon in the top left corner of
most illustrations, indicating which finger assembly mode
to use.
Sometimes a joint mode icon will be used to identify a
board.
These are the four joint mode icons:
TD Tails
(tails for through dovetail joints)
TD Pins
(pins for through dovetail joints)
HB Tails
(tails for half-blind dovetail joints)
HB Pins
(pins for half-blind dovetail joints)
2
3

v
CONTENTS AND STANDARDS D4R Pro User Guide
Which Way Round Should the Board Go?
As virtually all dovetail joinery is used to make boxes,
drawers and chests etc., we devised these simple (and
hopefully intuitive) icons to indicate which side of a
board faces inwards or outwards on the finished “box”,
and which side of the board faces outward (toward
you, the operator), when it is clamped in the jig.
The following symbols indicate:
This edge against sidestop
This edge against sidestop
Sawcut allowance
฀Caution: use special care for this
operation
Numbered References in text
฀This icon indicates the
“outside” of a board. All
through dovetail pin boards
are mounted in the jig with
this “outside” face away
from the jig (toward you, the
operator).
฀This icon indicates the
“inside” of a board. All half-
blind pin and half-blind tail
boards, and through dovetail
tail boards, are mounted in the
jig with the “inside” face away
from the jig toward you, the
operator.
฀This icon indicates boards
that are mounted both ways
e.g. sliding dovetails and end-
on-end dovetails.
Dotted line icons indicate
the “other” side of the board
in the illustrations.
Centreline of board or layout
Equals
Does not equal
Approximately

CONTENTS AND STANDARDS
vi
D4R Pro User Guide
Contact your dealer for more details
Add Leigh Accessories to make your jig even more versatile.
Leigh Brand Bit Sets Offer Great
Savings...and the Box Is Free!
Save over individual bit prices. Each top quality
bit set includes a box with foam insert that
accepts all shank sizes, and a handy bit chart in
the lid to list out all the bit specs. Choose from
7-piece, 10-piece, 12-piece or 16-piece Bit Sets.
Combine the VRS with a Bit Set
for Exceptional Savings!
The D4R Pro Accessory Kit is the best deal going.
Enjoy great savings on the 12-piece Bit Set and
even greater savings when you combine it with
the VRSD24 Vacuum & Router Support.
Finally, Dust-Free Routing
and Superb Router Support!
A must-have!
The VRS Vacuum & Router Support is the ul-
timate dust and chip collector. As an added
bonus, the VRS provides full width router sup-
port to your D4R Pro. It’s simple to attach and
the collector adapts to most popular vacuum
hose sizes.

vii
CONTENTS AND STANDARDS D4R Pro User Guide
Contact your dealer for more details
Optional Leigh Templates and Attachments
Super Precise, Super Easy
Finger Joints
Finger joints are very strong, aesthetically
pleasing and easy to produce. Add a Finger
Joint Template to your D4R Pro Jig and rout
perfect finger joints in minutes.
Six Unique Isoloc Joints,
Only from Leigh
The patented Isoloc joint gives any corner
joint a very unique look. These one-of-a-kind
patterns will really set your woodworking
pieces apart from the rest. Great savings
when you buy all three templates.
Classic Multiple Mortise
and Tenon Joints that Last
The Leigh M2 Attachment is the only one of
its kind. The multiple mortise and tenon joint
is ideal for “shelf to upright” construction
and produces extremely strong joints that
stand the test of time.
Need a Helping Hand?
Use Leigh Hold-Down Clamps
Leigh Hold-Down Clamps are tough, versatile and
immensely strong! They employ proven cam-action
technology developed for the award-winning Leigh
jigs, the D4R Pro and FMT. Bench clamps can be used
in any size hole and surface clamps can be mounted
on any flat surface, both on any angle. You can never
have too many clamps!

CONTENTS AND STANDARDS
viii
D4R Pro User Guide

10
1 2 3 4
5 6 7 8
9
Jig Assembly, Mounting,
and Using the Clamps
D4R Pro - CHAPTER 1
Make Sure You Have All the Parts.
Before you start to assemble your Leigh D4R Pro, check to make sure you have received all the required parts.
The small carton you removed from the end of the main
carton contains:
1. 1 Leigh e7 Elliptical Guidebush & Pin Wrench
2 Spacers
2. 2 Dovetail bits, 1 straight bit, 1 Collet Reducer,
3. 2 scale assemblies with 5⁄64" hex key
4. 2 support brackets
5. 2 support bracket knobs
6. Square-head guidefinger screwdriver
7. 4 clamp springs
4 clamp T-bolts
4 flat washers
4 T-bolt nuts
2 square nuts
1 flat head machine screw
1 Leigh wrench/gauge
4 Jig Hold-down Nuts & Machine Screws 1⁄4"-20
8. 4 cam-action speed clamps
4 cam clamp step washers
…and any other small optional items you may have
ordered with your new jig. Check the packing slip for this
information.
The main carton contains:
9. 1 main jig body
1 Leigh jig User Guide
Warranty/Registration Card
DVD instructional video (English only)
The large inner box contains:
10.1 finger assembly on 2 bars
D4R Pro has 26 guidefingers (13 pairs)
2 lengths bridge extrusion
1 cross cut fence
1 nylon Stop Rod
2 clamp bars
If any items are missing from your jig, contact your supplier
or Leigh Industries immediately.
See Appendix IV - Customer Support.
Important Note
Mount your jig securely and assemble it completely before you try to
use it.
Make sure you have read and understood all the material in the Safety
section of this user guide before using the jig.
1

JIG ASSEMBLY, MOUNTING, AND USING THE CLAMPS
2
Chapter 1 D4R Pro User Guide
35/16"[84mm]
6"[150mm]+
295/16"[745mm]
37"[940mm]+
1"[24mm]
1
2
4
3
1-1 Prepare a flat board at least 3⁄4"[20mm] thick, and a mini-
mum of 37"x6"[940x150mm]. Drill four 9⁄32"[7mm] holes on
29
5⁄16"x 3 5⁄16"[755x84,2mm] centres, 1"[24mm} in from the front
edge of the board . Countersink or counterbore the under-
side if the board is thicker, so that the four 1⁄4-20x1" long machine
screws will project above the top surface by 3⁄8"[9,5mm] .
1-2 Turn the jig body upside-down on two blocks (to protect
the side stops). Using the four nuts and four countersunk machine
screws, bolt the base board to the jig using the two nut recesses in
each end housing. Holes drilled 1"[24mm] from the front edge
of the board go to the front of the jig. Now you can clamp your
D4R to any bench.
1
1-3 With the jig right side up, insert one square nut (part #284)
into each of the channels in the main extrusion. These nuts are
for possible future attachment of accessories.
1-4 Insert the four clamp T-bolts into the T-slots (two at each
end of the jig). Position so that the washers seat into the round
milled recesses. Tighten the four clamp bolt nuts with the Leigh
wrench.
1-5 Place four springs and two clamp bars on the T-bolts.
Make sure the clamp bars move freely on the T-bolts.
1-6 Place one black step washer ฀on each T-bolt with the
flat side against the clamp bar. Screw a clamp lever assembly onto
each T-bolt, making sure the cam lobes are between the step
washer sidewalls.
1

3
JIG ASSEMBLY, MOUNTING, AND USING THE CLAMPS Chapter 1D4R Pro User Guide
1-7 Insert the right and left support brackets. Attach the
knobs, raise to full height and tighten. Note: For clarity, the set
line is drawn in red. The actual lines are black.
1
1-8 Place the fingerassemblyon yourbenchwiththe guidefinger
screws ฀on top and the pointed ends of the guidefingers away
from you. Fit the scales onto the finger assembly, placing the
HB TAILS scale ฀to the right at both ends. Do not tighten
the scale set screws ฀yet.
2
3
1
2
3
1-9 Slide the complete finger assembly with loose scales onto
the support brackets. Set the bracket index line at 3⁄4 "[20mm] on
the HB TAILS scale and tighten the thumb screws . Tighten
the scale screws ฀firmly with the hex key provided. If the scales
are removed from the finger bar for any reason, follow this
procedure to re-attach them.
1
2
1-10 Loosen the thumbscrews and make sure the finger assembly
slides on and off the support brackets smoothly, in both the tail
and pin modes. Move the outermost guidefinger at each end of
the finger assembly outward to touch the scales, and tighten. This
finger acts as an end support for the router and is not generally
used as a guide.
1-11 You will operate the cam-action speed-clamps every time
you use the jig, so get used to the feel of the clamps first. Use
some square ended boards for practice. Make sure the end of the
board is touching the underside of the guidefingers. Then slide
the board over against the side stop.
90˚
1-12 Do Not force the cam-action speed-clamp. It has great
leverage, and excessive force may damage the workpiece or the
jig.

JIG ASSEMBLY, MOUNTING, AND USING THE CLAMPS
4
Chapter 1 D4R Pro User Guide
1-13 A smooth, firm action is enough to engage the clamp.
Rule of thumb: If you can’t throw the lever comfortably by pressing
the end of it with your thumb, reduce the tension. A few minutes
of trial and error will help you feel the right clamp tension. Firm
thumb pressure is about right.
1-15 When engaged, the front clamp levers should point down
and the rear clamp levers should point away from the operator.
1-16 If the lever is badly positioned at the correct clamping
pressure...
1-17 Release the clamp, remove the board and turn the step
washer a quarter turn (the step height inside the step washer is
one quarter of the thread pitch).
1-18 Then adjust the clamp until the clamp lever is in the right
position at the right pressure.
1-14 Do Not use the lever as a torque arm. Adjust the clamp
tension only with the clamp disengaged.

5
JIG ASSEMBLY, MOUNTING, AND USING THE CLAMPS Chapter 1D4R Pro User Guide
1-19 For all but the wider workpieces, you need only operate
the clamp on the workpiece end ฀of the jig to release the board.
For narrower boards, the clamp at the free end ฀should be just
tight enough to bow the clamp bar about 1⁄8"[3mm] greatly
exaggerated in this view.
1
2
3
1-20 Make up a spacer board. This board will be used to support
the finger assembly in all front-clamping vertical board modes.
The spacer board should be flat, straight and of even thickness.
We suggest 3⁄4 "x6"[20x150mm] by approximately 23" [580mm]
long. Note: the thickness of the spacer board has no relationship
to the thickness of the vertical board being routed.
1-21 After you have assembled and mounted the jig, you will
have some items left over:
1 straight router bit Leigh No.140-8
1 dovetail router bit Leigh No.80-8
1 dovetail router bit Leigh No.120-8
1 collet reducer
1 Leigh wrench
1 accessory attachment screw
1 hex key (allen wrench)
1 Leigh e7 elliptical guidebush
1 pin wrench
1 Leigh guidefinger adjustment screwdriver
2 Spacers, one for single pass dovetails, one for box joints
2 lengths of bridge piece extrusion
1 Cross cut fence
1 Instructional DVD, and this user guide.
Please keep all these items for ready use.
1 Warranty Card. *Please register your warranty. You will automati-
cally be entered in Leigh's Warranty Registration Contest.
1-22 To gain height for a more comfortable working position
or for routing longer boards, mount the jig to a box that can be
bolted securely to a bench.
See also fig.17-15 
1"[24mm]

JIG ASSEMBLY, MOUNTING, AND USING THE CLAMPS
6
Chapter 1 D4R Pro User Guide

7
2-1 Practice adjusting the finger assembly height. Loosen the
support bracket knobs and hold them firmly. Raise and lower the
assembly evenly, keeping it level, and tighten the knobs to lock it
at various heights.
2-2 Do Not raise or lower one end of the finger assembly at a
time.
2-3 To practice adjusting the guidefingers, put a board in the
front clamp. Always raise the finger assembly slightly, approxi-
mately 1⁄8"[2mm] above the spacer board and/or workpiece .
This is essential to allow the guidefingers to move freely on the
guidefinger bar and ensures that the fingers will be level and
flush when locked up. Move the guidefingers by pushing on the
middle to slide them along the guidefinger bar.
1
1
2-4 Loosen about half the guidefingers and practice unlocking,
moving, positioning and re-locking them. Always press down
lightly on the centre of each guidefinger when tightening the
screws.
If after loosening a finger it "sticks" and doesn't slide, see header note
above.
1
Adjusting the Finger Assembly
D4R Pro - CHAPTER 2
THE FINGER ASSEMBLY IS THE HEART OF THE LEIGH JIG.
Spend a few minutes now to familiarize yourself with these simple adjustments.
NOTE: The first few times you use your jig, some fingers may "stick". This is normal. To "unstick", loosen the finger
screw approximately 3/4 of a turn, and with the screwdriver still in the screw, press down firmly (on the screwdriver).
This will loosen the finger locking wedge (you should feel a click). The finger will now move freely.
7

ADJUSTING THE FINGER ASSEMBLY
8
Chapter 2 D4R Pro User Guide
2-5 Do not over-tighten the guidefinger locking screws. The
Leigh screwdriver provided will give ample torque for easy lock-up
without strain.
2-6 Always tighten unused guidefingers before routing, as router
vibration will cause loose screws and wedge nuts to fall out and
be lost.
2-7 You can adjust the guidefingers by eye, or by measurement
to suit a set of plans.
Note: Always lower the finger assembly down onto the workpiece
before routing. 

9
3-1 Traditionally, guiding routers on almost all dovetail jigs is
achieved by using a fixed, cylindrical template guidebush fitted to
the router base. A round 7/16"[11,1mm] guidebush (min. depth
1/4" see page 69) will allow for routing of through, half-blind,
and sliding dovetails on the D4R Pro. Here are some examples of
Leigh’s system of fixed guidebushes.
1
1
1
3-2 Your D4R Pro is supplied with the unique Leigh e7-Bush*,
a template guidebush that is adjustable in size. Unlike regular
circular template guidebushes , the e7-Bush is slightly elliptical
in cross section . This simple innovation effectively changes the
guidebush “diameter active size” when it's rotated, and provides
benefits not possible with a standard round guidebush.
1
2
3-3 The e7-Bush (or 7/16") fits to the router base or to a guidebush
adaptor in the base, See 3-1. The ellipse or oval shape major axis 
is ~7/16"[~11mm], its minor axis is ~.020"less[~10,5mm].
Rotating the bush 90 degrees in the router base changes the effective
guide size by .020"[,50mm]. This provides repeatable adjustment
settings for perfectly fitting box joints.
1
21
2
~7⁄16"[~11mm] ~27⁄64"[~10,5mm]
~.020"[,5mm]
adjustment
3-4 Here’s how it works. In normal use on a dovetail jig, the
operator does not rotate the router more than a few degrees either
way . In fact, because of potential bit-to-bush eccentricity prob-
lems it is advisable to minimize router rotation on jigs .
1 2
How Routers with
Guidebushes Work
D4R Pro - CHAPTER 3
THE GUIDEBUSH IS THE VITAL LINK BETWEEN ROUTER AND JIG.
Here's how it works.
9

HOW ROUTERS WITH GUIDEBUSHES WORK
10
Chapter 3 D4R Pro User Guide
1
3-5 Establish the orientation in which you normally hold and
operate the router on the jig. Now, up-end the router in the same
orientation. Make a small scratch line or permanent ink mark on
the router base or e-Bush adaptor at the 12 o’clock position .
3-6 Fit the e7-Bush to the router and align No.10 to the scratch
mark. Note: Some Leigh guidebush adaptors may need modifying to
allow the e7 to rotate in the base, see Appendix I.The No.10 setting
is used for all through and variably spaced half-blind dovetails
on D4R Pro. Settings for single pass half-blinds, box joints and
sliding dovetails are described in applicable chapters.
3-7 The bit goes through the guidebush and fits in the router
collet or chuck.
3-8 The projecting part of the guidebush runs along the side
edge of the guide finger. The rotating bit cuts the wood only, and
touches neither the guidebush nor the guide surface. 

Basic Jig Functions and Scale Modes
D4R Pro CHAPTER 4
11
Here are the very basics for understanding the different D4R Pro dovetail modes and settings.
2. TD PINS
3. HB TAILS
4. HB PINS
1. TD TAILS
THE FOUR SCALE MODES
The Finger Assembly attaches to the support brackets in four
different modes to match the type of joint you are cutting.
Note: Inch scales are shown
here. Millimetre scales have
identical layout.
The active scale is always
on the right of each scale
assembly.
The inactive scale is always on
the left of each scale assembly
and is upside-down.
Scales are colour coded.
Silver background for
Through Dovetails.
Green background for Half-
Blind Dovetails.
The specific settings for each
scale are fully described in
the appropriate chapters.
Each scale has its own mode
icon (a drawing of the joint
part made in that mode).
This index line is used when setting the finger assembly
scales. The line is illustrated in red for clarity, but is black
on the jig.
Always read scales from
directly overhead to avoid
parallax problems.
All D4R Pro jigs are shipped
with "short" support brack-
ets.

BASIC JIG FUNCTIONS AND SCALE MODES
12
Chapter 4 D4R Pro User Guide
4-1 The two clamp bars hold workpieces horizontally or verti-
cally. The side stops align the boards in the correct position each
time.
4-2 The guidefinger assembly slides on to the support brackets
above the workpiece. The finger assembly is adjusted in or out
using calibrated scales on each end to suit different thicknesses of
vertical boards.
4-3 The finger assembly is raised or lowered using the support
brackets to suit different thicknesses of horizontal boards. 