The stock rip fences that come with many table saws leave much to be desired, and there is a booming business in improved, after-market fences. One of the more popular fences is the Biesemeyer T-square® saw fence system, which provides an rugged, accurate, and reliable fence constructed from standard structural steel shapes, rather than from custom aluminum castings and extrusions. The simplicity of construction and the cost of over $300 for the commercial version of the fence convinced me to try to make my own.
This article describes a fence I built for my table saw. It resembles, and was based upon the Biesemeyer T-square® fence, and is thoroughly rigid and accurate to 1/64" using a vernier cursor. The fence angle can be easily adjusted parallel to the blade or to provide slight clearance past the blade. The fence has tapped holes to simplify mounting of auxiliary fences, and is sufficiently high to provide a place for push sticks and to hook extra fingers during narrow rips.
I built this fence about thirteen years ago, and I continued to refine it for a few years after that. Since then, Beisemeyer was bought by Delta, and I replaced the saw and fence with something I like better.
About four years ago I gave away my table saw and fence after I found an Inca model 250 tilting-table saw for a reasonable price. Since the table height-adjusting mechanism was broken and replacements were unavailable, I made a new mechanism out of solid aluminum, straightened a few bent castings, and I have been enjoying the exquisite precision of this Swiss beauty ever since.
The Inca has a completely different fence than the one descibed on this page; is lightweight, easily knocked off square, and has no builtin measuring scale but, when used with care, it can be very accurate. I sometimes miss the ruggedness and ease of setting rip widths that I enjoyed with my shop-built fence, but I have never missed the vibration, wandering settings, and general crappy construction of my old imported contractors saw.
Please note that I took no photographs of my old fence, nor did I make drawings, and my memory of it is beginning to fade, so this slightly-edited description is about all that I can provide for those who may want to try to build one, themselves. Those wanting more concrete illustrations are encouraged to examine the advertising literature from Delta, Jet, and other machine manufacturers.
A front angle supports the front rail and extension table. On the front of the saw is mounted a 3"x3"x.250" steel angle, with the corner down. Attachment uses 1/4-20 bolts on 10" centers, with holes drilled and tapped into the saw table top (alternatively, you could use any existing holes in the top). The top edge of the angle is flush with the top of the saw table, with cut-outs for the miter-slots.
A 2"x3"x.125" rectangular-section front rail rests horizontally on the front angle with a gap large enough for the fence cross angle to clear. The rail supports the fence cross angle, and has a Starrett stick-on measuring tape for the gauge. The rail extends past the front angle on the left and right ends to support the fence cross angle through the full range of fence positions. The front rail is attached to the front angle using 1/4-20 bolts from the bottom of front angle on 10" centers, into Thread-serts (made by Creative Engineering). The .125" rail thickness is needed to resist crushing from fence clamp. The front rail must be perpendicular to the miter slots, uniformly distant from the edge of the saw table top, and parallel to the top in the horizontal direction; shim and/or enlarge bolt-holes to adjust.
The fence cross angle is 2"x3"x.250", long leg horizontal, short leg dropping down between front angle and front rail. A 23" length is adequately rigid. Although I welded my fence bar to the cross angle, very-accurately drilled holes and bolts might be rigid enough. (A first attempt, using 4: 1/4-20 bolts in oversized holes failed because I could not tighten the bolts enough to prevent slipping during use.) The ends of the short leg are drilled and tapped for 1/4-20 short bolts with the heads on the front-rail side, and with jam nuts on the front angle side. The heads of the bolts need to be ground flat and a little thinner, as they are used to adjust fence squareness. Note that only slight adjustments are possible. These bolt heads are covered with flat springs made of 4.5" lengths of old hack-saw blades, mounted at the inboard ends using two 8-32 or 10-24 screws each. (To drill hacksaw blades see spot annealing. The ends of the springs over the bolt heads are covered with little pieces of Formica glued on with epoxy, to act as low-friction glides. The springs and glides also help keep the bolt heads from turning when sliding the fence.
Fence clamping uses a Destaco toggle clamp mounted on a piece of angle welded between cross angle and fence bar, hanging down to make a local U covering the front rail. A piece of brass is bolted between the front rail and hanging angle, and hangs down to the pressure point on front rail. This isolates the shearing forces from the clamping force produced by a bolt through the slot in the toggle clamp. The fence has 3-points of contact with front rail: the two ends of cross angle behind front rail and the bolt on the toggle clamp. Clamping pressure is adjusted by screwing the clamping bolt in or out. It is important to mask out any paint on the front and back of the front rail at the lines of contact to avoid chipping and wearing off paint and affecting accuracy.
Any fence length can be built, but don't forget to add half the sum of the widths of the fence bar and cross-angle to the desired maximum rip widths. For example, my fence bar is 4.5" wide and my cross-angle is 23.5" wide, so for a 50" right and 12" left rip capacity, my front rail must be 50 + 14 + 12 + 14 = 90" long.
As the stiffness of beams is proportional to the cube of the depth, and as the accuracy and stiffness of the T-square is linear with the width, be careful about reducing the width of the fence bar, front rail, or cross angle. It is essential that the cross-angle rests below the table top, so be careful about using too shallow a front angle.
Thick metal is required for the clamping surfaces; the original .080" front rail dented from repeated clamping. I found a steel supplier locally that caters to home builders and, although they charged a premium prices, their prices were lower and selection was much better than at the local home center or hardware store.
I used oversized bolt-holes and bolts to allow room for adjustment. In view of some of my errors, this was prudent, but a neater job would use counter-sunk, flat-head screws in accurately-drilled holes. The cast-iron table drilled and tapped nicely, although cutting, drilling and tapping the 1/4" steel was miserable. If you mount the front and rear angles first, you can easily clamp the front rail and fence pieces in place to check clearances, etc. You will want to build and fit everything together, then disassemble and paint. Zynolite Epoxy Rust Mate paint worked very well, and scotch tape did a fairly decent job of masking off the clamping lines on the front rail (it was hard to get off, though). Wax has prevented rust in these unpainted areas. If you paint the top of the front angle and the underside of the front rail, a piece of Mylar packing tape between them will allow adjusting the angle and spacing without the paint sticking (permanently) to itself.
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Building a Table Saw Fence / firstname.lastname@example.org / revised 2006 December 27