Miter Saw Upgrade With a New Blade and Laser

I did my first miter saw upgrade by replacing the stock blade with a high quality finishing blade and then installing a third party laser.

My miter saw is a 12″ DeWalt DW715. It is overall a very nice miter saw (highly recommended) but I wanted it to be even better. This article is pretty specific to that particular saw, but the general concepts on why to do this as well as the end results will be applicable to most miter saws.

As usual, if you are a moving pictures type of person, then I have a video for you:

Note that my conclusions in the video don’t completely match the conclusions in this article because I had not yet nailed down exactly how to use the laser by the time I finished the filming.

Visually Why

The first issue is lining up where to cut. If you don’t have a laser, then the standard method is to strike your cut line on the piece and then (with the saw off!) lower the blade down so that one of the teeth is touching exactly where you want it to cut.

A blade will often have teeth that either go more to the left or more to the right. I try to pick a tooth that is aimed at the non-waste side of the board and place it so it just kisses the layout line. This cuts directly on the line.

This is a relatively quick and accurate way to line up the cuts on a flat and square piece. It becomes quite a bit harder if the piece is in any way irregular. Compound cuts on an angled piece of molding, for instance, are no fun at all using this method.

Also, having to strike a perpendicular layout line can add an addition step that can introduce its own possibility of inaccuracy.

Most miter saws come with a general purpose construction blade and the DW715 is no exception. It’s a 32 teeth GP blade and while it’s not terrible, it doesn’t cut cleanly at all.

Here it is on a piece of plywood:

Note, too, the row of lifted shards on the length of the piece:

This is very typical for a cut with a GP blade. It is almost never better than this and it can certainly be far worse.

The Upgrade Plan

Based on this, I decided I wanted to upgrade the saw in two ways. The first was to replace the blade with a “finish” blade. I chose the Freud Diablo D12100X which is a 100 tooth “ultimate finish blade”. For 12″ blades, anything above 60 teeth is considered a finish blade. I chose this blade in particular since it was a good combination of a trusted brand (Freud) and price (substantially less than some of its competitors).

The second was to add a laser. I didn’t even know that it was possible to add a third-party laser until relatively recently. The one I chose was the Oshlun LG-M01 based primarily on the reviews plus the price.

It is possible to add a second laser to the other side that should show precisely the area that the blade will cut. I’ll consider doing that in a future upgrade… maybe.

Step One: Raise the Lower Guard

The lower guard needs to be moved up and out of the way since it defaults to shrouding the blade screw entirely in its installed state. That is, you cannot access the blade screw to remove the blade until the lower guard is moved!

To do this, you must loosen (but not remove) the lower guard screw. You can find the screw by just moving the primary “upper” blade guard up and out of the way. It’s right there on the left side of the blade. It kind of looks like it could accept a flat headed screwdriver, but when I tried using one, it proved to be an odd enough size and tightly enough in there to discourage such use. Instead, the intended use is the torx head that’s on the back of the included blade wrench.

The wrench primarily has a socket head that fits the blade screw but, yeah, it’s also intended to be used on the lower guard screw. Not sure why the manual says nothing about that. The torx bit fits perfectly into the lower guard screw and it doesn’t take much effort to loosen it. A little WD-40 or similar can help persuade it, if necessary.

Here’s an important bit of (missing) information — the amount that you loosen the screw does matter!

You need to loosen it enough so that a curled flange on the guard can pass underneath it. You’ll note that if you loosen it just a little, that the guard won’t more more than a millimeter or so. That’s because that piece of the guard that is sticking up is hitting the head of the screw.

You’ll now that the screw is advanced enough if the upper blade guard rests on it when you let go. The picture shows both the upper guard resting on the screw and the lower guard’s flange passing underneath the screw head. If the upper guard still closes all the way then you haven’t loosened the screw enough.

After the screw is loosened, just push the lower guard up and out of the way. It should move reasonably easy. It’s moved enough when you can see the blade screw in the center of the blade.

Step Two: Remove the Existing Blade

The blade will spin freely normally so it won’t stay still when you try to unscrew it. That’s where the spindle lock comes into play. This is a button located on the main housing just to the right of the blade and underneath the handle.

Press that down and give the blade a spin. It will eventually “catch” and you’ll feel the spindle lock drop down a bit. That locks the blade into place. Note that it is spring loaded or something so if you let go of the spindle lock button and remove any pressure on the lock with the blade, then the lock will spring back and the blade will spin again. You can let go of the button as long as you maintain constant pressure on the lock, but it’s probably easier to just keep it pressed down with one hand.

Next up is unscrewing the blade screw using the included wrench. You will likely want to spray some lubricant on it first as it might be a bit sticky.

This part is extremely important: the screws are left-handed threads or “backwards” threads! You may have learned the old adage of “lefty-loosey; righty-tighty” or “clockwise-lockwise” or similar. Well, forget that entirely. To loosen the blade screw, you need to turn right or clockwise and essentially pretend that you are tightening it.

Left-handed threads always feel so wrong when you’re using them.

Anyway, if it’s properly lubed then it shouldn’t take too much effort to remove the screw. If it’s taking a lot of effort, then make sure you aren’t turning the wrench counter-clockwise (or anti-clockwise).

Remove the outer blade clamp and set it aside. This allows you to remove the old blade.

Note that there is a washer on the arbor. That’s because the arbor is 5/8″ but most 12″ blades have a 1″ arbor hole. The washer is a spacer to make those fit. If your replacement blade has a 1″ arbor, then just keep it there. If, however, you have a blade that has a 5/8″ hole… then just remove the washer and set it aside somewhere where you won’t forget it.

Step Three: Installing the New Blade and Laser

To install the new blade, just insert it onto the arbor from whence you removed the old blade. Simple.

If you are not installing a laser, then at this point you just replace the outer blade clamp and screw it back into place.

I did install a laser, though, so that’s next.

The laser is almost exactly the same size as the original outer blade clamp. It’s exactly the same diameter and almost exactly the same thickness.

The LG-M01 already has its three batteries installed and does come with three spares. The batteries activate when the laser is spinning rapidly, so there is no off/on switch.

Since it’s exactly the same dimensions as the outer blade clamp, we shall simply use it in place of the clamp during the reinstallation. Store the blade clamp somewhere safe.

That’s pretty much it. Make sure the writing on the laser is on the outside. You might also verify that the path of the laser isn’t being blocked by a carbide tooth… but in the case of the 100 tooth blade, that’s pretty tricky to do and so I didn’t think it was worth the effort.

Tighten the blade screw by turning it to the left or counter-clockwise or anti-clockwise. “Lefty-tighty” in this case. So so wrong feeling.

Step Three: Lower the Lower Guard

You’d think that lowering the lower blade guard back into place would be trivial and it may well be for some of you. It wasn’t for me, though. I couldn’t get enough leverage on it and for a bit, it just refused to move past a certain point. I tried various tools and all failed until I finally just grabbed the flange that sticks out with some pliers (linemen pliers) and pulled down with a pretty decent amount of force. That finally worked!

After the guard is down, just tighten the screw using the torx end of the wrench until it’s snug. It has standard thread orientation so there’s no need to think backwards.

The After Test

Now for the after tests!

First up, I strike my normal layout line and line up the blade using my normal method. Then I turn on the saw to start the laser and view where it shows up.

Basically, it hugs the layout line so closely that it’s difficult to see the line anymore. It technically cuts just to the left of the blade so it would be just to the left of the line. In practice, I found it difficult to line it up quite that precisely.

Moving on to the cut quality, though, we find this:

Wow! I’d need a zero-clearance insert to get a cleaner cut than that. And the face of the cut is actually smoother than the factory edge, even. Very impressive!

But let’s go back to the laser. One of the big advantages of using a laser is that you don’t need a full layout line nor are you restricted to flat and square pieces. A far more precise way of marking the location of a cut is to make a “triangle” mark with the point of the triangle right at the desired measure point. This is more precise because you don’t care about the width of the pencil line nor do you introduce a separate step for striking a line that bisects the measured point. If you cut right at the triangle bisection then you’re guaranteed a super precise cut.

So I did a cut on a test piece that has some funky angles and I just did the triangle method to mark the location of the cut. This cut would be difficult to do accurately using my old method. I lined up the laser just to the left of the bisection point, so that none of the laser was on the right side of the triangle.

The result is a night-and-day difference. My cut was so close to my measurement that I would likely need a micrometer to tell the difference.

Final Impressions

Upgrading the blade is a no-brainer. It did cost me $60, but it’s worth every penny of that. With a blade like that, I can make cross cuts that rival the smoothness of my table saw. Plus, doing the swap is pretty darn easy. Yes, I had a few issues as I went since the manual proved to be almost worthless, but after I figured out what to do, it was all straightforward. I can likely change out the blade in a minute or two, going forward.

The laser is a curious one in that it’s not so immediately obviously awesome. It was only after playing around with it for awhile that I discovered how useful it could really be.

See, there’s the first major drawback to all third party lasers in that they only work when the saw blade is spinning. That’s because there is one laser on the device that is pointing straight forward. It needs to spin in order to create a line. They all have internal sensors which activate only when it is spinning so that they don’t waste any battery. I’m not a huge fan of having to start up the saw just to make the final adjustments for the positioning of my piece, though! I’m going to think about my possibilities of maybe adding some kind of external switch to the outside of the device that will allow me to turn it on even when the blade is still.

My original tests (and those that I talk about in the video) were all at least a little disappointing since they didn’t increase my precision or accuracy over the manual method of lining up the cut. This was because I was using the less-accurate way of marking the cut line, though. It was a revelation when I switched to using the triangle style method! Now I’m finding that my precision is approaching table saw levels. That’s pretty darn impressive.

I’ve mentioned my table saw twice so far and said that this upgrade makes the miter saw competitive. The table saw does still have to big advantages. One is that it has a zero clearance insert that allows for completely chip free cuts. My miter saw with the new blade comes close to that, but not exactly. Well, one of my future plans is to make a miter saw station that will include a removable zero clearance insert. I suspect that I’ll have identical cuts after that.

The second advantage of the table saw is with repeatable cuts. That is, when using a fence or using a stop block on a cross cutting sled, I can cut piece after piece that are perfectly identical in size. No amount of measurement will get you that same repeatability. That’s where my future miter saw station comes into play. That will have an integrated ruler and stop block system that will get me my repeatable cuts.

One final advantage of using a crosscut sled on a table saw is that I can visually see just how wide my cut is going to be, based on the zero clearance opening on the sled. With my laser, I only have one side marked. It turns out that if I care enough that I could do something about that. It’s possible to get a laser made for a radial arm saw that is slightly thinner and install it on the right side of the blade. This would give me a laser line on both sides of the blade that are separated exactly by the blade kerf. It would also allow me to place my finished side on either side of the blade instead of always on the left, as with my current laser. I’ll consider doing that.

But for $25, that laser is already worth the money for what it does as-is.

All told, this was an $85 upgrade and I could scarcely be happier with the results.