Over time you might notice that your miter saw isn’t working quite like it used to, back when it was fresh out of the box. Time takes its toll, also the years of blaming your miter saw for your bad cuts might have finally hurt its feelings. I kid, however, it’s likely that after 5-10 years of regular use you might have your miter saw brake stop working.

You’ll know this happens as your miter saw blade keeps spinning after you finish the cut. Usually the blade stops after a second or two once you release the trigger. Over time you might notice that it takes a little longer to stop, or doesn’t stop at all and you’re waiting for the blade to stop on its own.

A Miter saw blade that keeps spinning after the cut means that your electric brake is faulty. Don’t fret, this isn’t a hard problem to fix. A simple brush replacement is typically more than enough to get your miter saw back in tip top condition.

How does a miter saw brake work

Some older miter saws (pre 1990s, roughly) used to have little brake pads that would get pushed into the blade once the trigger was released. This stopped the blade from spinning. This was safer than letting the blade spin, but not great as the pads would need to be replaced and could also get stuck against the blade. 

Over time, motors with brushes became popular and major power tool brands realized they could simply reverse the power to the miter saw, making the blade want to spin in the opposite direction for long enough to stop it. This method is far better. Over time you will need to replace your miter saw’s brushes, as it can lead to more problems than just the brake malfunctioning.

Here’s a quick video about power saw electric brakes, the video is about circular saws, but it’s the same function for a miter saw.

Why is my miter saw brake not working?

Basically, miter saw brushes send power to your miter saw, and spin the blade. The electric brake works by reversing the power after the cut is made and the trigger released. These brushes wear out over time.

Brushes are little carbon blocks on springs, then need to make contact with the spinning axle that the blade is attached to. This contact of course wears the brushes down over time. Once worn down enough they you will see a loss in performance. The brake isn’t the only thing bad brushes can affect.

Miter saw electric brake repair process

Most miter saws will need a brush replacement around the 10 year mark, depending on how much use your saw sees. However, this is definitely one of those maintenance items that if you can do before you run into issues you’ll save yourself a lot of problems.

A miter saw brush replacement is fairly simple and cheap. If you’re handy it can take you about 20 minutes and about $15-$30 depending on how easy it is to get replacement parts near you. 

You can check out my miter saw brush replacement guide to see how this is done.

Bad brushes can cause sparking, grinding and shaking that can affect the quality and precision of your cuts. So as soon as you notice a loss in performance I highly recommend getting this done.

You might be tempted to just ignore this altogether, and I don’t blame you, I’ve certainly put this type of thing off before. It is sort of a safety issue, as the blade spins for longer than it normally does.

However, if you’re putting your material or hand anywhere near the blade ten seconds after making a cut you need to seriously rethink your habits. The main reason I argue for not putting this repair off is because the problem will only get worse, you’re sure to see sparks in the near future, and the less stress put on your saw the longer it will last after you make the replacement.

Why your miter saw keeps tripping the breaker

Your miter saw trips the breaker or dims the lights during a cut, because power saws draw high levels of power, quickly. Many homes cannot handle a sudden surge in demand, resulting in the breaker tripping. A soft start adapter can help this issue.

Miter saw trips GFCI or AFCI

This is most commonly a problem in older homes with less capable power outlets and circuits. However, newly built homes or poorly wired homes can also have this occur. If you’ve ever noticed your lights flicker or quickly dim when your washing machine changes cycles or someone turns on a hair dryer, it’s likely a miter saw will trip the breaker.

Whether you have GFCI or AFCI installed in your house, your miter saw can keep tripping the breaker. These types of safety features are more designed to protect your home from fire, and users from electrical shock.

In other words your miter saw will continue to trip the breaker even with these types of receptacles installed in your home.

Chop saw keeps tripping breaker, same problem

In the eyes of your home’s breaker, chop saws and miter saws are the same. They run at about the same RPM and draw a similar level of power in order to reach top speed. 

You might be wondering at this point, “why aren’t power saw manufacturers doing something about this?”. In fact, some are! Some major brands like Bosch sell models of miters saws that have a “soft start” feature. This means that the saw slowly speeds up over the course of about 5 seconds. This is much easier on your breaker and these miter saws don’t trip the breaker at all. 

The trouble is, is that adding a soft start feature to a saw is pricey. You’re looking at about an extra $80-$150 for a miter saw with a soft start vs one without. This is why soft start is not a standard feature. It isn’t necessary for most users, however, for the users who need it, it’s vital.

What is a soft start for a miter saw?

So what’s the easiest and cheapest solution for keeping your miter saw from tripping the breaker? Adding a soft start adapter is both the cheapest and easiest solution. These adapters plug into the outlet, and then have a plug for your miter saw. This way your power saw isn’t directly connected to the outlet, but has to pass through the adapter first. These are just as good as a soft start feature.

Here’s a great video explaining soft start adapters:

I want to mention a couple important things about using soft start features with your miter saw. First, is a safety precaution. Miter saws without a soft start feature reach full RPM very quickly and you don’t really have to allow the blade to speed up, because it happens usually in under a second. This speed is why it’s tripping the breaker in the first place.

With a soft start, you must allow the miter saw to reach its full speed before making the cut. If you don’t you can cause your miter saw to bind, this can damage the material, the miter saw blade and the internals of your saw. Give it at least 3-5 seconds to reach full speed.

The next point is that soft start adapters aren’t cheap. They start at $80 and can easily reach $200 for home use soft start adapters. Not cheap for an addon feature I know. However, if you’re having this problem with your miter saw, you’ll likely see the same problem in other applications in your home.