The Ultimate Table Saw Crosscut Jig

Author: Rob Brown
Photos: Rob Brown
Illustration: Len Churchill
Published: June July 2021
table saw crosscut jig
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A quality table saw crosscut jig will help you make accurate, repeatable crosscuts every time.

  • DIFFICULTY
    3/5
  • LENGTH/TIME
    2/5
  • COST
    2/5
crosscut sled material list

Mitre saws are versatile, as they can cut your workpieces at a wide range of angles and are portable, but I find there’s something very pleasing about a table saw crosscut jig. Maybe it’s the fact that I can see the line I’m cutting to clearly. Being able to quickly and easily change blades on my table saw, depending on the material I’m cutting, is also help­ful. For some of us, the extra space needed for a mitre saw (that are only growing in size) is a luxury we don’t have. For a jobsite, the mitre saw is king, but I find I’m using mine less often these days, and I don’t want to dedicate the space for one. But keeping my mitre saw tucked away raises an important question: How will I cut narrow pieces like trim, door frames, etc. to length, and possibly at an angle? Making my own versatile crosscut jig was the obvious answer.

A Third, Partial Layer
Once the first two layers of plywood are glued together and trimmed flush, Brown added a third layer of plywood. This third layer was cut 6" short, and doesn’t extend to the far end of the jig. The 6" wide cavity created will be filled with a removable zero-clearance insert.

Mark Screw Locations
With the jig positioned properly against the mitre gauge, mark the locations of the holes that will secure the jig to the mitre gauge. Brown made sure the groove he machined after this step didn’t extend up to this line.

A Pair of Rabbets
With the extension bar groove complete, Brown used a rabbet router bit to machine the two rabbets on either side of the groove. He then glued a strip of solid wood into these two rabbets.

T-Nut Cavities
After marking the locations on the back of the jig, Brown bored four holes that allowed him to hammer in T-nuts. Bolts holding the replaceable zero-clearance insert in place will thread into these T-nuts. If the T-nuts aren’t set below the jig’s rear face the entire jig won’t sit flat on the mitre gauge.

All the Way Through
With the insert taped in place, 1/4" diameter holes are drilled through the jig and insert.

Hammer it Home
Use a piece of hardwood to hammer the T-nut below the outer surface of the jig.

Recess for the Bolt Head
Usually a Forstner bit’s center spur keeps the bit from wandering or the piece from shifting, but in this case holes have already been drilled in this zero-clearance insert. As long as the bit is advanced slowly and the piece is held securely, things will work out fine. If you’re unsure, drill a slightly oversized hole.

Tape is Temporary
The extension bar pressure cleat is fixed to the jig with double-sided tape, then a hole is drilled through the cleat and jig into the extension bar cavity.

Bore for a T-Nut
A T-nut needs to be installed in the rear side of the extension bar pressure cleat. Bore the holes, then hammer in the T-nuts.

Carve a Glue Trough
With care usually reserved for a fine piece of furniture, Brown added a groove around the perimeter of the face of the cleat that gets glued to the jig. This minimizes glue squeeze-out from happening.

Shapely Handles
After routing rough cavities for the heads of the T-bolts, Brown used epoxy to securely adhere the T-bolts to the wood. When dry, he shaped the handles.

Wooden Stop Block
Brown marked, then cut a dado to help position the extension bar stop block in place. It gets clamped to the extension bar with a 2" lightweight C-clamp.

What’s the function?

Before making a shop fixture like this I want to be sure I know what the main functions are. To crosscut a single piece of wood, I can just grab my standard mitre gauge and make the cut to a marked line, but I needed something for cutting multiple parts to the same length, and potentially at an angle. This was my main focus. Many of the parts I work with are shorter, as I’m not cutting baseboard or crown. But having said that, I don’t want to have a huge jig to store when not in use. The ability to add an extension to this crosscut jig when needed is critical.

Materials

Many commercial crosscut jigs and mitre gauges are made mostly, or even entirely, of metal. This was an option, but I’m a woodworker, not a metal worker, and wood offcuts are just hang­ing around my shop waiting to be used, and I have the tools and machines to do that.

I did use some metal in this jig, though. Metal is the perfect mate­rial for a lot of the hardware that will keep a jig like this working for years to come. A standard mitre gauge forms the foundation for my jig. It fits in my table saw’s mitre slot, allows me to angle the jig in relation to my blade and is super durable. T-track allows me a lot of options for making wood stops that will give me the repeatabil­ity I need. That, coupled with T-bolts, makes for a sleek solution. Some additional miscellaneous 1/4-20 hardware helps bring this jig together in a clean, strong and lasting manner.

Baltic birch plywood 3/4″ thick and solid hard maple will pro­vide a dense, smooth surface for years of use.

The build

The overall dimensions of this jig aren’t critical. Everyone has different requirements. You can adjust the overall length or height of the jig to meet your needs.

Start by cutting and laminating two pieces of plywood together. The pieces should be at least 4″ wide and an inch longer than you want to make your crosscut jig. When you’re gluing the two pieces together, make sure they’re flat. I glued them on the sur­face of my table saw. An accurate crosscut jig needs to be dead straight. When dry, trim it to 3-3/4″ wide, but don’t worry about the length yet.

Cut a third layer to the same width and length of the 1-1/2″ thick assembly, then trim 6″ off one end. The longer piece will be glued to the 1-1/2″ thick assembly, while the offcut will be used as a removable zero-clearance insert. Glue the longer piece to the other two, flush with one end, yet keep one long edge about 1/16″ inside the other during glue-up. When dry, rip the edges straight and even, then trim the ends smooth.

A groove and two rabbets

Cut a 1-3/8″ deep × 5/8″ wide stopped groove somewhere vaguely close to the center of the 2-1/4″ wide edge. Stop the groove before the future location of the screws that will attach the cross­cut jig to your mitre gauge, as the screws will need the material to bite into, and the screws will interfere with the solid wood extension that will fit into this groove. I set up a stop to limit travel and made this groove with mul­tiple passes, though a router and straight bit (also with multiple passes) would also work nicely.

Once the large groove is done, run a router equipped with a rabbeting bit along both inner edges of the groove. The resulting rabbets should be about 1/4″ high and 3/8″ wide. The exact mea­surements aren’t critical, as you’ll be machining the strip of wood to fit into these rabbets, so you can size it accord­ingly. Next, machine and install the solid hardwood base strip in those two rabbets. I machined this piece about 1/32″ thicker than needed. When dry, I trimmed the strip of solid wood to the end of the jig, then I laid the jig on its side and ripped about 1/16″ off its height to create a flat, even bot­tom. The exact finished height of the jig when complete isn’t overly important.

Rabbet track

The aluminum T-track needs a rabbet to recess it into the upper front edge of the jig. It’s not the end of the world if the top of the T-track sits slightly proud or below the top of the jig, but when machining the depth of the rabbet, take a bit more care to get it very close. If anything, you want the face of your T-track to sit ever so slightly back from the face of the jig. Machine the rabbet, then drill screw clearance holes in the track and install it with #6 screws.

Zero-clearance plywood inserts

These inserts will support the tail end of the cut and reduce tear-out as the workpiece exits the blade. You should make a few now, and even label these inserts depending on the width of the blade. These inserts were 6″ wide, and the jig was screwed to the mitre gauge so the blade is centered on the inserts. There will be about 3″ of jig extending beyond the blade.

Cut the inserts to fit the area, then tape one insert in place. Put your mitre gauge in the table saw slot, position the jig against the mitre gauge and screw it to the mitre gauge.

Mark the locations of the four holes needed to bolt the insert to the jig and drill 3/4″ diameter holes, about 1/4″ deep, in the rear face of the jig in these four spots. This will recess the T-nuts into the surface of the jig. This step is necessary so the bolts will be able to engage with the threads on the T-nuts without extending past the rear surface of the jig and without butting into the mitre gauge. Next, drill a 1/4″ diameter hole through both the insert and the jig.

Remove the insert, tape it to the other inserts, and bore all the 1/4″ holes through the rest of the inserts. At this point I marked the bottom edge of the inserts so they would be easier to install down the road.
Bore a 5/16″ diameter hole about 3/8″ deep on the back face of the jig. This hole will accept the center threaded section of the T-nuts.

The last series of holes to be bored were in the faces of the inserts to allow the four bolt heads to sit below the surface of the insert’s face. It’s not easy to drill a hole with a Forstner bit centered over another hole because the center point of the Forstner bit isn’t engaged in wood, but using a drill press and clamping the work­piece to the drill press table so it doesn’t move should work quite well. You could also use a slightly larger Forstner bit and just hold the insert with your hand and not need to worry if it slides around a bit while drilling. Drill slowly and there should be no problem. Repeat this for all the inserts.

Extension bar pressure cleat

A block of wood, fitted with a pair of T-nuts on its inner surface, needs to be attached to the rear face of the jig so an extension arm can be secured in place. Machine the block to size, temporarily affix the block to the rear face of the jig with double-sided tape, then drill a 1/16″ diameter hole where the two T-nuts are to be located. This hole should extend to the center groove in the jig.

Remove the block and bore a 3/4″ diameter hole in its inner face, about 1/8″ deep. This hole will allow the T-nuts to be recessed below the inner face of the block so the block can be glued to the jig. Finally, bore 5/16″ diameter holes through both the block and the jig so a T-bolt can be threaded through the T-nuts and used to apply pressure to the extension bar.

Install two T-nuts in the inner face of the block, then glue it to the rear face of the jig, making sure the center of the T-nuts are cen­tered over the center of the two holes in the rear face of the jig.

Extension bars

You could just make one long extension bar that would allow you to cut workpieces to any length required, but I find most of the work I do isn’t overly long, and it’s more difficult to work with a long extension bar when a much shorter one will usually do. I opted to make two extension bars; one about 32″ long and the other about 72″ long. The 72″ long extension bar will allow me to cut multiple parts up to about 96″ long. It’s rare that I need to cut pieces longer than that. These extension bars are also very easy to make. Dress clear hardwood stock to fit in the cavity, break the sharp edges, drill a hole in one end and hang it on your shop wall near your table saw.

Wood knobs

Although there’s likely hardware that could be purchased, I opted for a shop-made solution here. One word of caution: If you pur­chase knobs, most jig hardware handles are about 2″ wide, and might come into contact with the table saw’s table while in use.

I had extra T-bolts, so I traced their heads onto the edge of some hardwood, free-hand routed a 3/16″ deep cavity with a 1/4″ diam­eter straight bit, then epoxied the T-bolts in place. When they were dry, I shaped the handles to size, making sure their heads weren’t too large.

Stop blocks

At least two stop blocks needed to be made. One for clamping to the T-track in the jig; the second for clamping to the extension bars.

The stop block for attaching directly to the jig uses a bit of 1/4-20 hardware to promote easy clamping and quick adjustment, while the block for the extension bar is very simple, and just gets clamped in place. I’m sure there are many options for creating a sleek clamp­ing system to secure the second block to the extension bar, but I didn’t feel I needed to get that fancy.

To make the first block, I cut some solid maple about 1/16″ nar­rower than the height of the jig and 3″ long. The 1/16″ gap at the bottom of the stop will allow sawdust to slide under the stop block and not interfere with cutting parts to the proper length. I drilled a clearance hole 3/8″ from its upper edge so a bolt could extend through the block and engage with the T-track. To ensure the stop block always sits square I added a small strip of wood to the top of the block. This strip of wood will rest on top of the T-track and help with alignment.
After marking the location of the dado, the stop block for the extension arm was dadoed to mate with the underside of the exten­sion arm, then it was sawn to shape. This stop block finished at 7/8″ thick and 2-1/2″ square. The dado was cut 3/8″ deep. Ensure the stop block will actually allow a workpiece to butt up against it, rather than passing very closely past it, when the block is clamped in place.


Rob Brown - [email protected]

Rob is a studio furniture maker and the editor at Canadian Woodworking & Home Improvement.

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