The key to accurate right-angle cuts is to square up the miter gauge to the saw blade. Don't trust the angle indicators on the gauge; they're far too sloppy. Instead, go to an art supply or woodworking store and buy a 45-degree drafting triangle. Set one side against the blade and align the gauge to the other side (Photo 1).
Be sure the side of the triangle against the blade falls between the teeth tight to the blade “plate.” For greater accuracy, have the blade cranked all the way up so you're squaring to the widest part of the blade. Choose a straight 1x2 or 1x3 board at least 12 in. long for the extension fence (Photo 2).
Sometimes you'll need a longer fence, but more on this later. Screw the fence to the miter gauge with the right side projecting a few inches past the saw blade. All miter gauges have a pair of screw holes or slots for this purpose. Choose screws short enough so they don't penetrate all the way through the wood.
Photos 4 and 5 show you how to test the accuracy of and fine-tune your miter gauge setting. You'll find that even tiny adjustments have a big effect.
Raise the blade all the way and hold a combination square vertically against the blade and the saw table. Adjust the blade tilt as necessary. Don’t trust the saw's tilt angle indicator. Ours was off by two full degrees.
To make precise square cuts, start by rough-cutting long boards a few inches longer than the final length, with either a circular or a miter saw. (Boards longer than 4 ft. are awkward to cut on a table saw.) Then raise or lower the blade so it’s about 1/8 in. higher than the board's thickness.
Position the factory end of the board just past the end of the extension fence so the blade will just shave it, and then start the saw. Always recut factory ends; they're rarely perfectly square. Hold the board snug against the fence and slowly push it through the blade. After each cut, slide the board away from the blade and turn off the saw before you remove cutoff pieces.
Now mark the exact length at the other end and align that mark with the end of the extension fence (Photo 1). Then make the final cut.
Perfect miters are almost as easy as crosscuts. Start by setting the miter gauge to 45 degrees (Photo 1).
Mount an extension fence, moving it toward the blade far enough to cut the end at a 45-degree angle (Photo 2). Then make the fine cuts on your material. Hold your material very tight; the saw blade will try to pull it off line. In general, it's best to make all your miter cuts first, and then any square cuts at the opposite end, where it's easier to be accurate.
For the kind of extreme accuracy needed for complete squares such as picture frames, cut two test boards, push the miters tightly together and check the assembly with a drafting square. If it's not perfect, adjust the miter gauge and repeat. Again, it only takes very small adjustments to make big differences.
Any board much over 4 ft. long is tougher to cut accurately because the table on the saw will no longer support it. As you struggle to keep it flat on the table, it often binds in the blade. Clamp a piece of plywood or closet shelving (the slippery edge helps the wood slide) to the top of a sawhorse.
To adjust the height of the support board, hold a level or a straightedge flat to the table until the board is even with the table top. Resist the temptation to have a buddy support the other end while you push it through the blade. That's dangerous. Avoid that dicey human element.
Cutting newel posts, table legs or other thick stock to length has to be done in two steps. Set up your fence exactly as before. A higher fence, at least two-thirds the thickness of the wood, gives better support. Then the trick is to make a first cut halfway through and flip the wood over to finish the cut.
With this technique, the blade guard will block the wood from going all the way through the blade. You'll have to remove it for this task, so cut with caution. Be sure to keep your fingers well away from the blade while you make the cuts.
Portable Table Saws
You don't need to use a stationary table saw like we show in this article to make nice crosscuts. An ordinary portable table saw will do just fine for most cuts. The size of the material you can cut will be limited by the size of the table and the distance from the saw blade to the miter gauge. However, make sure to anchor the saw securely when you're cutting long or heavy material.
When you're building a cabinet, a piece of furniture or nearly any other project, just about every component will need a matching partner (or several partners) of identical length. The trick is to cut the first board at exactly the right length and then use it to establish a stop block to cut all the others. Here are two techniques for that process, one for short boards and the other for long ones.
If boards will be shorter than 18 in. or so, it's best to use a slightly longer extension fence and clamp a stop block to the fence (Photo 1). Cut a slight angle on the stop block. That'll keep saw dust from accumulating between the block and the board. Sawdust buildup will result in boards that are just a wee bit on the short side.
It's impractical to have an unwieldy extra-long fence to cut long identical boards. Instead, clamp a secondary fence above the boards and clamp a stop block on the end of that fence as shown in Photo 2. Select extension fence stock that's tall enough to handle both the thickness of the board and the clamp for the secondary fence. A 1-1/2-in. x 3/4-in. board works well for the secondary fence.
The table saw is arguably the most dangerous power tool in the shop even when you're using it for crosscutting. Here are a few tips to keep you as safe as possible.
- Always unplug the saw when you're squaring up the blade with a drafting square.
- Make sure the safety guard support lines up with the blade. There are adjustments on all guards. If it's not lined up, boards can get hung up on the support right in the middle of a cut.
- It's OK to just shave a little from the end of a board. But avoid cutoffs that are shorter than 2 in. The blade will often catch shorter cutoffs and send them flying.
- Never use the table saw rip fence as a guide for cutting wood to length. The wood will become trapped between the fence and the saw blade and pose a serious kickback hazard.