Most Unifence owners love the flexibility and accuracy of Delta's
innovative fence. But many of us bemoan the inability to use
simple sleds and jigs because of it's unique shape.
One of my primary design goals was an add-on that would not prohibit
the use of the built-in ruler. I have become accustomed to the
accuracy it provides and do not want to lose that feature.
Additionally, I would like to avoid drilling or cutting the
fence. Lastly, I would like it to be easily removed (i.e. not
I spent a lot of time working out designs and had a lot of good ideas -
but a method of securing it easily to the fence eluded me. One
day I discovered that the head of a 3/8" carriage bolt fits nicely into
the two slots that are used to secure the fence to the carriage. Then
came a sudden epiphany: with the fence horizontal (instead of the usual
vertical position), one of the slots was available for securing add-ons
to the Unifence! In
hindsight, it's really pretty obvious. The resulting design is simple
to construct, install and remove. It provides a 3.5x6"
rectangular shape that easily accepts sleds and jigs.
Building the fence
Construction of the fence is relatively
simple, as seen in the diagram, below. However, there are a few
things about this fence that are
critical to get right:
1. The front face the fence (A) must be perfectly even with the front
edge of the
Unifence (U). If it is not, then readings on the Unifence rule
2. The front face must be 90 degrees to the table.
3. The top face must be parallel to the table (if you intend to build
jigs to ride on the top of the fence).
1. Cut your 3/4" stock to size for parts A-D. I used MDF...the
Bigafence is much more useful if it is straight.
2. Cut the dadoes and rabbets in A-D, except for the tiny rabbet at the
bottom of A. Note that the exposed dadoes on A and C are optional
- cut them only if you intend to intall t-track.
3. Note the bevel on B. This is required to clear the edge of the
Unifence carriage...it may not be necessary on all models.
4. Next, drill holes in C and D for the mounting hardware (H1 and
H2). Countersink the holes in C for H2. I located them 8"
from the ends.
Now, dry-fit the parts with some clamps - it's time to start the
adjustment phase. I considered listing the exact sizes of the
remaining parts and cuts, but I do not know if the Unifence has varied
over the years. I think it is better to describe the steps that
helped me get a very precise fit.
5. Cut the final rabbet at the bottom of A a little at a time.
Gradually increase the depth of the rabbet until the left face of A is
even with the left edge of the fence.
6. Once the face is even, we need to work on the angle of the fence
face to the table. You can adjust it two ways, by increasing the width
of the rabbet
in face A or knocking a little off the bottom of B. The goal is to get
the face 90 degrees to the table.
7. Now that the face is even with the left edge of the fence and
perpendicular to the table, we are ready to adjust part E. The purpose
of E is to prevent the Bigafence
from sliding to the right on the fence. We should not rely on the
force of the bolts to keep it in place - movement during a cut could be
very dangerous! Slowly adjust the width of E until it fits snugly
in place and the Bigafence
cannot move left or right on the Unifence.
8. You're ready for the glue-up. I recommend gluing the parts and
clamping it while installed in position on the Unifence - and ensuring
that the face is perpendicular to the table.
9. Finally, to make the top perpendicular to the face, run face C
across the jointer. Make sure face A is firmly against the jointer
10. Install the t-track in the dadoes in A and C (optional).
11. For a finish, I simply waxed the visible surfaces.