Workshop Projects. Jeff Jacobson
Now, for the T-slot system. The efficient use of this bench really revolves around jigs made with a T-bolt and a knob clamp. The T-bolt slides in a metal track that’s secured to the bench with screws, and then the knob on the bolt is tightened to hold the jig in place. The track will last through a lifetime of use.
Installing the metal track requires a simple 13/16"-wide x 3/8"-deep groove. Make sure the groove depth is accurate: If it’s too shallow, the track will stick up into the work surface, and if it’s too deep, the accessories will pull the track out of the groove. Lay out the track grooves on the maple rails, as shown in the end view detail on page 4. Then, chuck a ½" straight bit in your router, and attach a straightedge guide. Now, rout one 3/8"-deep pass for each track, and then reset the edge guide to make a second pass, widening the grooves to 13/16".
Since the track comes in 40" lengths, this bench requires four pieces to make up the two parallel slots. To secure the tracks, set them into the grooves, and drill 5/32"-diameter holes every 6". Next, drive a #6-1" panhead screw (pieces 16) into each hole. If the track overhangs the end of the bench, cut the excess off with a hacksaw.
Figure 3: A drilling jig ensures accurate dog holes; just be sure to switch the fence for each row.
Bench Top Details
Drilling dog holes in the bench top requires a great deal of accuracy, so it helps to use a jig for this operation (see Figure 3). The idea behind the jig is to use one dog hole to establish the position of the next hole. To ensure accuracy, I incorporated a portable drilling guide into my jig. Since the jig is guided by the maple rails, you’ll have two fence positions: one for the right-hand row of holes and one for the left-hand row.
Build the jig, and then set it against the bench top to drill the first hole, referring to the dog hole locations drawing on page 2. Drill the hole, and then use a center punch and the forward hole on the jig to locate the next hole. Now, move the jig forward until you can slip a 1" dowel through the rear jig hole and into the first bench hole. Lower the drill bit to the second hole location to make sure the bit spur goes right into the punch mark. Drill the second hole, and use the center punch to mark the third hole. Continue this procedure for the rest of the dog holes. When you’re done with the right-hand row, switch the fence, and then drill the left-hand row of holes. The more accurate your dog holes are, the better off you’ll be when using your bench jigs.
On the back end of the bench top, the T-slots are left exposed so you can slip your fixtures and jigs in and out. On the front end, however, you must install an endcap. Cut the endcap (piece 12) and the vise jaws (pieces 13 and 14) to size, and then follow the exploded view detail on page 5 to drill their mounting and vise screw holes. Clamp the endcap into position against the bench top, and extend the pilot holes into the maple rails and the plywood lamination. Now, secure the endcap to the bench with glue and screws (pieces 18), extend the pilot holes for the inside vise jaw, and secure it with lag bolts and washers (pieces 17).
At this point, the bench top and the base are ready for assembly. Square the top on the base, and then clamp the two together. Now, reach under the bench to extend the pilot holes in the aprons and supports. Use #12-2½" screws (pieces 18) to secure the assembly.
Quick Tip
Flip Boards in a Panel Glue-Up for Tighter Joints
You can significantly improve the quality of a rubbed glue joint (two boards joined on edge) by putting a pencil mark on the top of each board and then running them through the jointer. Keep one board’s mark against the fence and the other’s mark away from it. Then, if the jointer is even the tiniest bit out of alignment, the two cuts will compensate each other. Turn one board end-for-end, apply glue, and press them together—this will spread the glue more evenly. Then, realign the boards correctly before clamping.
Material List – Workbench Cabinet
| T x W x L | ||
| 1 | Sides (2) | ¾" x 8¾" x 21⅝" |
| 2 | Top (1) | ¾" x 22⅜" x 47" |
| 3 | Bottom (1) | ¾" x 22⅜" x 47" |
| 4 | Back (1) | ¾" x 8¾" x 47" |
| 5 | Dividers (2) | ¾" x 8¾" x 21⅝" |
| 6 | Drawer Sides (6) | ¾" x 7" x 21¼" |
| 7 | Drawer Backs (3) | ¾" x 7" x 12⅞" |
| 8 | Drawer Fronts (3) | ¾" x 7" x 12⅞" |
| 9 | Drawer Faces (3) | ¾" x 8¼" x 15⅛" |
| 10 | Drawer Bottoms (3) | ¼" x 12¾" x 20¼" |
| 11 | Slides (3 Sets) | 20" Blum Side Mount |
| 12 | Knobs (3) | 1½" Dia. |
Some Final Thoughts
Next, make the bench dogs (pieces 19 and 20), as shown in the dog detail drawing on page 5. If you don’t plan to build the drawer cabinet,