I use a lot of plywood for making cores for the veneering I do, and needed a way to cut the plywood accurately with­out breaking the bank on manufactured guides. These guides allow me to easily cut parallel to the factory edge. Even when the factory edge isn’t perfect, I can set these jigs slightly wider and then come back and clean up that not-so-perfect side. Other times, I need several pieces all the same size and these guides make quick work of that, too.

Accuracy breeds accuracy

Any jig that needs setting to a dimension needs to be made accu­rately. In this case, the ends of the rails need to be square and the measurement setting guide accurate to transfer the proper width of cut. This isn’t difficult using well-made plywood such as Baltic birch.

Start by gathering your hardware; T-bolts, washers, nuts, knobs and aluminum T-tracks. I chose the 24″ length as this is the most useful size for my work. You could make these as long as you’d like, depending on your shop needs. While the measurement set­ting guide isn’t absolutely necessary, I feel for the small amount of extra work it takes to make, you get an accurate way of setting the guides. You could also make this jig without the aluminum tracks, but I think they add a level of accuracy, give the guides a clean look and makes them easier to use.

Time for some milling

All the pieces are cut from a small section of 9/16″ or 14mm Baltic birch. You could get away by using 3/4″ or 19mm thick ply­wood, as that would leave much more material under the T-track to work with. Cut the pieces for guides, adjusting the length to make the rails longer if you’d prefer.

The T-tracks fit in slots cut into the rails. A router works nicely for this task. Use a 3/4″ router bit and cut to slightly over 3/8″ deep in a few passes. I cut the slots to a length of 25-1/2″ which gave me 3/4″ on each end to slide the T-bolt into the rail once assembly started. Also, the routed slot starts 1″ from one end of the ply­wood rail. The slot for the measurement setting guide rail is just as long and deep, however, increase the width to 1-7/16″ to accept the wider T-track. I used the same 3/4″ bit and adjusted the fence after the first pass to make up the difference. All of these grooves are machined so they’re centred on the plywood rails. I also chose to square the top and bottom of the slot in the measurement setting guide rail for a cleaner look. You could do the same for the main rails but I liked the rounded look on them.

Getting sticky

I used an epoxy with a 20-minute set time to fix all three tracks into their respective slots. Since they sit slightly below the surface of the rails, I cut some narrow strips of MDF to fit into the slot in the track to help apply pressure and ensure the track was fully seated in the groove. I applied the epoxy and clamped the tracks while the epoxy set. For the wider measure­ment setting guide, I used a wider piece of MDF to better spread the clamping force. Have some rubbing alcohol and shop towels ready to clean any epoxy squeeze-out before it hardens.

Slip and slide

Use more of the same plywood to make the sliding assemblies. Cut the pieces to size, according to the cut list. I added an angle to the side of the wings. Since the wings are small, I cut them on the bandsaw and cleaned them up with a block plane and some sand­ing. They don’t need to be perfect. These relief cuts provide a good visual indication of which side to register the guides to the track.

To assemble the sliders, first take a small piece of wax paper and slip it over the rail and under the wings. Use a clamp to hold the wings tight to the rail. Next, place the top flush with the sides and front of the wings. Apply glue to the bottom of the slider top, then use a pin nailer to attach it to the wings. Avoid placing glue where it contacts the rail, and as an added bit of security countersink a #8 × 1″ flat head wood screw on each side of the top into the wings.

Next, I set the bottom registration piece back from the front equal to the width of an engineer’s square blade (3/4″) and secured it to the rest of the assembly with two #8 × 1″ flat head wood screws. Don’t use glue here, as the bottom needs to be removed for final assembly.

Drill, drill & drill

Repeat the steps above two more times. Once the assemblies have been made, fine tune their movement by sanding the rails. It shouldn’t take much, and a small amount of wax will also help them move. It’s now time to drill holes into the tops to allow the T-bolt to pass through. Mark the location of each hole over the cen­tre of the T-track and in the middle of the top. Using a sacrificial piece between the wings and a 1/4″ brad point drill bit, drill these through holes.

Final Assembly

Once all the pieces have been drilled and sanded it’s time for final assembly. Slip a T-bolt into the T-track and place the top half of the sliding assembly onto the rails, capturing the bolt. Place a washer on top, then the knob and tighten it down. Screw the registering bar back onto the bottom.

In order to install the measuring tape onto the measurement set­ting guide, cut a shallow 1/32″ deep groove into the top of the rail, in line with where the tape is located on the T-track. This groove will just be the extension of where the measuring tape is located in the T-track. Line this up and use a router to cut this groove. In order to accurately stick the tape, measure and lock in the slider 5″ away from the top. You’ll also have to adjust for the kerf of the saw, as the saw will cut about 1/8″ into where the guide rails were. Make sure this measurement is to the bottom registration bar. Next, peel and stick the tape, keeping the correct distance from the mark at the front of the slider’s top.

Using the guides

The guides are easy to use. To set them for a specific cut – let’s say 6″ – slide the assembly to the 6″ mark. Next, take one of the guides, loosen the knob and register them bottom to bottom. Slide the assembly up and tighten the knob. You can set the second guide in the same manner, or register it against the other guide.

Clamp the guide rails to the workpiece, butt the cut-side of the track against the end of the rails, clamp it in place, remove the guides and make your cut.

Using a track saw with jigs makes it not only easier, but also more accurate. These guides are easy to make, won’t break any budgets and don’t take long to make. Now you can make parallel cuts all day long.

Illustration

Material and Hardware List