Mitre cuts (also spelled miter) are the only way to cut across the grain of solid wood, and makes use of mitre tracks in the table saw top to guide the wood into the cutting blade. Mitre operations do not use the fence, which would cause kickback if used in conjunction with the mitre gauge.
When cutting against the grain the fence will not be used, and needs to be moved completely away from the blade.
Mitre gauges are great for squaring cuts at the end of wood, or making angled cuts. There's lots of fancy jigs that can slide in the mitre track, but for this introductory class we'll focus on using the mitre gauge that's included with most table saws.
To make basic mitre cuts you'll need:
Calibrate Mitre Gauge
All mitre gauges are a little different, but most will have a method to calibrate for squareness and setting a few other commonly used angles.
This mitre gauge has a set screw that allows you to calibrate the indicator to 0°, and two more set screws at the 45° limit.
The standard for mitre gauge track is ¾" wide x ⅜" deep, however there are some models that have odd-sized tracks. If you're getting a new mitre gauge for your saw it's best to check the track dimensions to ensure your gauge will fit correctly.
Mitre Gauge Action
The mitre gauge can fit into either mitre track, depending on the cut. The material to be cut sits in front of the gauge and the mitre gauge slides along the track until the material makes contact with the blade, pushing through past the blade to complete the cut.
Before making any cuts it's a good idea to try sliding the mitre gauge along the entirety of the track to make sure there's no snags. The gauge should fit snugly and slide smoothly, with no slop between the mitre and the track.
Clean the mitre track from any debris, and if there are any sticking spots try adding a little paste wax in the mitre track to lubricate. You only need a very small amount of wax to lubricate, you shouldn't be able to see the wax if applied properly.
0° Mitre Cut
With the mitre gauge properly calibrated you're ready to begin cutting. Like ripping wood, the blade needs to be set to a height slightly higher than the thickness of the wood.
Start with the saw off. Set the blade height for your cut. Slide the mitre gauge into the track and ensure the mitre is set to 0°.
Place the material to cut in front of the mitre gauge and align the portion to cut with the blade, taking into account the blade kerf so you don't cut off more than you measured.
Turn on the saw and position your hands so they firmly hold the material against the mitre gauge, but safely away from the blade. In a confident and smooth motion move the mitre gauge towards the blade and push the material completely through the blade to make the cut.
Modified Mitre Gauge
After a few cuts with the mitre gauge you might notice that while it does a good job with smaller material, it can be a little more difficult to use with longer materials that require more support when cutting.
Almost every mitre gauge will have pre-drilled openings along the vertical portion that allows sacrificial boards to be mounted, allowing the mitre gauge to have a longer reach which can extend over the saw blade. These modifications to the mitre are a good way to keep your work tidy and precise, without sacrificing a finger.
The mitre gauge is great for making cuts perpendicular to the blade, but is really useful when it makes a cut angled to the blade.
There's a track on either side of the blade which allows the mitre gauge to change places, depending on the angle of the cut you want to make. When setting up your mitre to make a cut, pay attention to how your piece rests on the gauge. You want to have your work trailing the mitre, not leading it.
Take a look at the picture above - the wood is angled so that the material is trailing the mitre. Now take a look at the picture below, the wood is angled to lead the mitre gauge.
Don't lead with the material, lead with the mitre gauge.
Once you understand how the mitre gauge works you can combine the mitre with an angled blade and make a compound mitre cut. A compound cut is a cut that has two or more separate faces, in this case the angle of the wood approaching the blade and the angle of the blade.
Using the same precautions as when making both an angled cut and a mitre cut, a compound cut can be a great way to make some very tricky geometry easy with one cut.
Remember when I said to never use the fence when making mitre cuts? Well, this is the only time you're allowed to break that rule. The fence can be an incredibly helpful measurement tool when making repetitive cuts with the mitre gauge, but not how you're used to using it when ripping wood.
A scrap, square piece of wood can be clamped to the fence and used as a stopping block a measured distance away from the blade. What's important is that the stop block be set far enough back so that it doesn't interfere with the saw blade or fence when the mitre gauge is moved forward.
In the above image the top arrow shows the desired length I want my cuts to be, from the stop block to the saw blade is 5½". The lower arrow shows that the mitre gauge can move freely and not get caught up with the stop block. Also note, the stop block is set back enough to allow the wood being cut an unencumbered path during and after the cut. This will prevent any kickback from occurring.
Place the wood in the mitre gauge and slide it to the stop block. Turn on saw and firmly hold the wood to the mitre gauge and slide the wood through the blade completely to make the cut.
Once you have your stop block and fence dialed in, you can easily make many repetitive cuts with the mitre gauge. This is much faster than measuring each cut and accounting for kerf, especially if you have lots of the same cut to make.
Identical length cuts, thanks to a stop block and the mitre gauge.
Once you have the skill of making mitre cuts, a whole world of project possibilities opens up. Probably the most common application of mitres you see everyday are picture frames. Take a peek at the angled cuts at corners of picture frames; chances are it's a mitre cut. And now you know how to do it, too!
Making your own picture frame is a fun and easy project and can encompass a beveled edge, which we learned about in the Ripping Wood Lesson.
The last skills we'll tackle in this class are making dadoes and rabbets, which are partial depth cuts along the length of the wood. Let's go!