AW Extra – Adjustable Workbench

Adjustable Workbench

The coolest
bench ever:
It changes
size before
your eyes!

By Tom Caspar

My workbench has always been the heart of my small shop. When I made it years ago, I outfitted it with a good face vise, an innovative sliding tail-vise and a plain trestle base. But the bench’s height always bugged me. It was too low for some jobs and too high for others. 

I found a solution! I retrofitted my top with commercially-made adjustable legs (about $490, see Adjust-A-Bench Legs, below). I also built a new cabinet-style base for added storage space. 

Adjustability has saved a lot of strain on my back. When routing, I raise the bench; when sanding, I lower it. The bench has 12 different heights, from 28 to 44 in.

Buy the Hardware

Every experienced woodworker knows this rule, but
it bears repeating: Buy the hardware before you build.
With this bench, those critical parts are the adjustable
legs, the face vise and the tail vise. Check their dimensions
and the placement of their mounting holes, then
fine-tune the plans if necessary.

Build the Top

The top is fairly straightforward, but there are a
few things to consider as you’re building. The main
top (A1) may be composed of as many boards as you
want. Cut them 1 in. extra-long and rout slots for
splines (A8). You could alternatively use biscuits to
help with alignment. Glue the boards together, then
trim them all the same length (see Cutting List, page
53). Cut the dog board (A2) an extra inch long, too,
and drill the dog holes (Fig. H) before gluing the
dog board to the top, again using a spline or biscuits
for alignment. Trim the top and dog board to final
length using a router, straightedge and flush trim bit.

A solid wood top with a frame must be able to
shrink and swell with changes in humidity, or it will
crack. Rout spline slots in both ends of the top to
align it with the ends (A3). Don’t glue these splines or
the ends when you assemble the top. Use two lag bolts
to hold each end in place. Make an elongated hole
for the rear bolt (Fig. E), so the bolt can move with
the top. Drill extra-large diameter holes for the screws
that hold the tool tray (A6) to the top (Fig. D). They
allow the tray to remain fixed to the back (A4) and
the top free to move. Don’t glue the spacing cleat
(A7) under the top where it connects to the tray.

The tail vise is simplicity itself (Fig. F). Slide the dog
block (B1 and B2) along the guides (B3) before
attaching the right end (A3) to the top. The screw
mechanism for the vise comes with a loose plate that
fastens to the dog block and a threaded guide that fastens
to the bench’s end (see Photo, at right). After
drilling the hole for the threaded guide, rout the
inside of the hole with a 1/2 in. roundover bit to
accommodate the threaded guide’s curved shape (Fig.
E). Buy or make round bench dogs for the dog holes
(see Source, page 53). Finish the top with oil to keep
glue blobs from sticking.

Build the Cabinet

This cabinet is designed to be very rigid. Three
shelf dividers (C4) dadoed into the sides (Fig. J) prevent the cabinet from twisting. A double-thick top and a
stout base keep the cabinet box from bending. The cabinet’s
back (C6) prevents racking.

Here’s a few tips on making the base. Be sure to cut
two grooves in the top for the threaded rod before gluing
the top pieces (C1) together. Make the two top
pieces oversize before gluing. Place weights such as
bricks or sandbags on top of them to apply clamping
pressure. Glue on all the edging parts before you cut the
cabinet pieces to size (see Frameless Cabinet Joinery,
page 92), or cut and apply the parts one at a time after
you assemble the cabinet box. Using the latter method,
make the edging 1/16 in. extra wide and trim it flush to
the cabinet with a router.

Build the Drawers

The drawers are simple boxes with applied faces (Fig.
C). Loaded with tools, these drawers can get quite heavy.
Use half-blind or through dovetails for a strong joint
between the front and sides. Make the back of the drawer
boxes 1/16-in. narrower than the front, as specified in
the cutting list. A tapered drawer box is easier to slide. If
you use drawer slides, build the drawer boxes with parallel
sides.

To give each drawer maximum depth, glue the bottom
directly to the underside of the drawer box. Glue
plastic-laminate strips to the underside of the drawer
bottom and to the shelf dividers to additionally help the
drawers slide.

Fit the Base

The base and cabinet should be exactly the same
length because the adjustable legs fasten to both parts.
It’s best to build the cabinet first, then build the base and
adjust its length to fit the cabinet. To start, make the base
about 1/8 in. longer than the cabinet. After dry-fitting
the base, remove one of the short stretchers (D1, Fig. L)
and joint it a few times to fine-tune the base’s length.

Assemble the Bench

You’ll need a helper to put the bench together. First,
attach the base to the cabinet. Next, slide the threaded
rods through the holes in the base. Put on the adjustable
legs. One person must hold the nut on one end of each
threaded rod while the other tightens the nut on the
other end.

Raise the adjustable legs about halfway up to give you
clearance when attaching the top. Clamp together the
two telescoping parts of each end so the upper portions
are plumb. Place the top on the legs so the rear brackets
butt against the tool tray cleat (A7). Shift the top side to
side so the bracket on the left
end sits midway between the
face vise’s left rod and the
vise’s screw. Mark all the holes,
turn the top over, drill the
pilot holes and attach the top.

Sources

(Note: This information may have changed since this story's original publication date.)

Adjust-A-Bench, adjustabench.com, 609-882-3300, Adjust-A-Bench Leg Set, $430 plus $60 S&H.

Lee Valley, leevalley.com, 800-871-8158, Bench dog, #05G04.01, $15.50 ea.; Shoulder-Vise Screw (for the tail vise), #70G01.51, $29.50; Front Vise, #70G08.01, $57.50; Vise Handle, #05G12.03, $6.50 (2 required).

Horton Brasses, hortonbrasses.com, 800-754-9127, Shaker Style Cherry Cabinet Knob, #WK-7, $2 ea. (9 required).

Cutting List

This story originally appeared in American Woodworker September 2007, Issue #130.

September 2007, Issue #130

Purchase this back issue.

Click on any image to view a larger version.

Adjustable
metal legs
allow you
to raise or
lower the
bench to a
variety of
working
heights. Set
low, it’s an
excellent
assembly
table.

Raise the
top all the
way for
detail work.
A tall bench
is a wonderful
luxury.
It’s perfect
for drawing
sketches,
routing
inlay, sawing
dovetails
and
many more
jobs.

Fig. A: Exploded View

Fig. B: Door

Fig. C: Drawer

Fig. D: Cross Section of Top

Fig. E: End View of Top

Fig. F: Cross Section of End Vise

Sliding Tail Vise

The sliding tail vise
allows you to
clamp a workpiece
between
two bench
dogs.

Fig. G: Face Vice Mounting Holes

Fig. H: Bench Dog Hole Spacing

Fig. J: Cabinet Rabbet and Dado Layout

Fig. K: Plywood Cutting Diagram

Fig. L: Base Stretcher

Adjust-A-Bench Legs

Cabinetmaker Geoffrey Noden first
designed these legs for his own
shop. Their operation is very simple.
Each end is composed of two
heavy-gauge metal panels. The
adjustable panel has a series of
notches that engage a rod in the
fixed panel. Depressing a pedal
rotates the rod out of a notch,
allowing you to lower the bench. To
raise the bench, you just lift its top.

The whole system is so robust
that it can take an enormous
amount of weight. Its simplicity
ensures that it will work for many
years, even in a dusty shop. You’ll
find much more information,alternative
bench plans and castor sets
at www.adjustabench.com or by
calling (609) 882-3300.