Question regarding cutting with a circular saw

[jeff hanaoka]

Hi all - I'm new to the forums (and to woodworking in general). I have a question I'm hoping someone can help me with. I just got a new Dewalt DWE575SB circular saw and have made a few cuts with it. However, for the life of me, I can't seem to make a perfectly square cut (square to the face). I've checked to make sure the base of the saw is absolutely square to the blade. I've also tried two different blades, with the same result. Here's the strange part: when I inspect the board I've cut, the beginning of the cut is absolutely square; however, the end of the cut looks like it has flared to about 95 degrees. Is the saw defective, or am I doing something wrong? Any advice would be greatly appreciated. Thanks!

[Lee Schierer]

What size and type of wood are you cutting?

Not to be disrespectful, but is the blade installed so it rotates in the correct direction? The trick with circular saws is to let the saw cut at its own rate, don't force it.

[Jim Rimmer]

You might try a guide to run the saw against. Something like this speed square would work.

http://media.popularmechanics.com/images/speedsquare_430_0209.jpg

[jeff hanaoka]

Hi Lee - thanks for the quick reply. Yes, I'm sure the blade is installed correctly. The wood is 5/8" plywood. I've also tried setting the blade at different depths to see if that would make any difference, and it didn't seem to.

[jeff hanaoka]

Thanks for the quick reply, Jim. I actually did clamp a straight edge to the board. It is cutting straight on my line down the face of the wood, the problem is with the face of the cut - it is slightly greater than 90 degrees to the face of the wood. Sorry if I'm not explaining this well - my woodworking vocabulary is very limited.

[Alan Schwabacher]

Because your saw is following a straightedge, that should rule out the possibility of pushing the saw sideways so as to deflect the blade from a square cut. That needed to be ruled out because you said the cut was square at first, then changed. Anything that might make you push too hard (like a blade reversed) could encourage that.

So if your saw is moving in a straight line, what could cause the blade to deflect? One possibility is if the edge of the saw base that runs against the straightedge is not parallel to the blade. Then the straight line of the cut would not be aligned with the direction the blade wants to cut, and sideways force would be put on the blade. If this is the problem, frequently one edge of the cut is cleaner than the other. To check for misalignment, measure very carefully to see how far the edge of the base is from one tooth of the blade in front, then rotate that tooth to the back, and measure as precisely as you can from the base edge to the same tooth. If the measurements are not the same, some adjustment should be made.

[Kyle Iwamoto]

Is the wide part of the saw's shoe on the keeper part of the plywood? If the angle changes, I would have to say operator error. No offense.......

[Steve Baumgartner]

As Kyle said, no offense intended but this sounds like operator error. Do you have the wood well supported on both sides? If the side that the saw is resting on sags or flexes upward when it is nearing cutoff, that would do it.

[Keith Hankins]

Have you looked to see that the blade and base are parallel to one another. If it's off a hair, she will never track true. Back in the day when I got my PC it was reviewed to be true, and was set distance from the edge, so clamping a straitedge from a cut line was a lot easier. I used that setup with a forrest WWII 7.25 blade for a long time till I bought the tracksaw. Good luck.

[jeff hanaoka]

Because your saw is following a straightedge, that should rule out the possibility of pushing the saw sideways so as to deflect the blade from a square cut. That needed to be ruled out because you said the cut was square at first, then changed. Anything that might make you push too hard (like a blade reversed) could encourage that.

So if your saw is moving in a straight line, what could cause the blade to deflect? One possibility is if the edge of the saw base that runs against the straightedge is not parallel to the blade. Then the straight line of the cut would not be aligned with the direction the blade wants to cut, and sideways force would be put on the blade. If this is the problem, frequently one edge of the cut is cleaner than the other. To check for misalignment, measure very carefully to see how far the edge of the base is from one tooth of the blade in front, then rotate that tooth to the back, and measure as precisely as you can from the base edge to the same tooth. If the measurements are not the same, some adjustment should be made.

Thanks for the advice. I measured and it looks like the blade is perfectly parallel to the base edge. Is it possible that the blade could measure parallel while still, but be thrown out of line once it starts spinning?

[jeff hanaoka]

Is the wide part of the saw's shoe on the keeper part of the plywood? If the angle changes, I would have to say operator error. No offense.......

None taken - wouldn't be the first time! Yes, the wide part is on the keeper part of the board. I will go run a few more cuts on different boards to see if I can figure out what's going on.

[George Bokros]

I believe you are saying the cut edge is not square to the face of the plywood. If I am correct then that would mean the blade is not square (90*) to the saw base. Have you checked the blade to the saw base with a good square?

If the blade is 90* to the saw base then I would say it could be operator error in that you are tilting the saw left or right off the face of the plywood. The saw base must stay flat against the surface of the material you are cutting.

George

[Andrew Pitonyak]

As Kyle said, no offense intended but this sounds like operator error. Do you have the wood well supported on both sides? If the side that the saw is resting on sags or flexes upward when it is nearing cutoff, that would do it.

Going even further... can you try a cut where the board that you are cutting is sitting on something that you can cut into? For example, some sort of foam insulation so that you know for certain that the board does not flex while you are cutting it.

Also, do you still see this behavior if you make a cut such that the cut-off portion is very very narrow (like say 1/16" or less)?

[Matt Day]

First check that your square is indeed square. Put it against a known flat surface, draw a line, flip it and draw the line again and see if the lines match up.

What are you using to confirm the blade is parallel to the shoe? Tape measure? I would plunge the blade all the way down, measure the forward most tooth on the blade using an adjustable square so that the ruler just touches the tooth, take note of that tooth and rotate the blade so that tooth is all the way back, and see if it touches the same amount.

[Joe A Faulkner]

First check that your square is indeed square. Put it against a known flat surface, draw a line, flip it and draw the line again and see if the lines match up.

What are you using to confirm the blade is parallel to the shoe? Tape measure? I would plunge the blade all the way down, measure the forward most tooth on the blade using an adjustable square so that the ruler just touches the tooth, take note of that tooth and rotate the blade so that tooth is all the way back, and see if it touches the same amount.

And after doing this, rotate the blade 90 degrees and check again. And repeat one more time. It could be that you have a bent arbor - defective saw.

[Don Roberson II]

I have had a couple of Dewalt circular saws that the the blade was not set true perpendicular to the base. Some of them have adjustment for this & some do not. Check to see if the miter on the front of the saw is set at 0(if not place it at 0) & then check with a square on the base in reference to the blade to see if it is square

[Pat Barry]

Hi all - I'm new to the forums (and to woodworking in general). I have a question I'm hoping someone can help me with. I just got a new Dewalt DWE575SB circular saw and have made a few cuts with it. However, for the life of me, I can't seem to make a perfectly square cut (square to the face). I've checked to make sure the base of the saw is absolutely square to the blade. I've also tried two different blades, with the same result. Here's the strange part: when I inspect the board I've cut, the beginning of the cut is absolutely square; however, the end of the cut looks like it has flared to about 95 degrees. Is the saw defective, or am I doing something wrong? Any advice would be greatly appreciated. Thanks!
Based on your description it seems to me that a possible explanation is that the base plate may not be flat. Lets say the front edge is flat across and square to the blade such that when you start the cut and reference off the front edge of the base, the cut is square. If the plate was not flat over its entire length and width however, as you transfer the cutting pressure naturally from the front edge of the base plate to the rear, the saw may be torqued and result in a cut as you describe. Try making a cut, keeping pressure on the leading edge of the base plate. CHeck to see if the back left or right corner of the base plate is lifted off the plywood midway though the cut. If it is, my bet is the base plate is warped or twisted.

[Dennis McDonaugh]

You should make sure the saw is capable of cutting square. Here's what I would do, put two pieces of 3/4 ply or solid lumber together (one on top of the other) and clamp them down to your work bench. Adjust the depth of cut to just slightly more than 3/4 inches, then cut the top board without a guide. The saw is supported on both sides of the cut and there should be no deflection so if the saw is square, the cut should be square.

[Steve Rozmiarek]

The edge of your saw base that you are running against the straight edge may not be parallel to the blade. If the saw steers in a cut, you get the effect you describe. Your blade may also need replaced, a few bad teeth can steer the blade.

[Perry Holbrook]

Just for kicks, change the blade and see if it still happens.

[jeff hanaoka]

Just wanted to thank everyone for their advice. After following many of your recommendations on tests to perform, I've come to the conclusion that - as some here have suggested - the blade is not perfectly parallel to the base plate's edge. Most likely, the arbor is slightly misaligned. In any case, I have returned the saw. Now I need to decide if I should try my luck with another dewalt (I really liked the electric brake), or go with a milwaukee or makita at a higher price! Anyways, thank you all for your great advice!

[Tom M King]

That's what I did with a Dewalt bench grinder I recently bought-sent it back.

[johnny means]

Drink the Kool Ade:D. It's everything you'll ever need.

[Steve Rozmiarek]

Drink the Kool Ade:D. It's everything you'll ever need.

Johnny, I think that's enabling....

Would fix the problem for sure though!