Miter saw acting weird (re-titled thread)

[KingwoodFan1989]

Very strange................we'll get it.

Meaning "we get it" or "we'll get to the bottom of it"? 

If it's the second and nobody has a solution before Monday, I'll call DeWalt about it. Again, it shouldn't be physically possible for this to happen. I did read on another forum that a guy tried changing out the blade and it helped with the same issue, but wouldn't an out-of-flat blade affect BOTH sides? I got one De-Walt blade before that was a hair out of flat, so I guess this stock blade (a 32 toother) could have the same issue, but I feel like I'm in an episode of the Twilight Zone with this.

[Handplanesandmore]

I checked both before I bought them. With this type of straight edge, I held a couple of them edge to edge and flipped each several times to make sure they weren't out. I used it to check my jointer for coplanar tables (which it confirmed it had), and that machine works perfectly. With the square, I checked it by drawing a square line on a board, flipping the square, and verifying it was perfectly parallel, which it was and still is.

Not saying your square is not square, but the method you used (drawing lines) -- good for combo or engineer squares -- is not necessarily a reliable one in your case, because the top part of the plastic base which registered against the board when you drew might not be parallel to the bottom. You were checking your saw using the base of the square as the reference point.

As for the straight edge, do you have a reliable journeyman level to check against your aluminum ruler?

While your reference tools might not be the cause for your out-of-square cuts, verifying your set-up should begin with tools that you are sure about their reliability.

Assuming the measuring tools are as good as you thought, could you check the saw blade with a straight edge for his flatness and wind to rule out wobbling. Also unplug the saw, spin the blade by hand, and sight from the front to scan for any wobbliness.

One last thing to check: Examine your test piece -- is it true, flat and out of wind? If in doubt, use quality plywood as test pieces.

I understand your frustrations...brand new machines should not require a user to go through such frustrating set-up process.

By the way, no matter what you get from this forum, you shouldn't hesitate calling Dewalt for help. They may know a quick fix!

Edit: Do you know the tolerance of your saw? Is the out-of-squareness within the tolerance limit given for your mchine?
Simon

[KingwoodFan1989]

Not saying your square is not square, but the method you used (drawing lines) -- good for combo or engineer squares -- is not necessarily a reliable one in your case, because the top part of the plastic base which registered against the board when you drew might not be parallel to the bottom. You were checking your saw using the base of the square as the reference point.

As for the straight edge, do you have a reliable journeyman level to check against your aluminum ruler?

While your reference tools might not be the cause for your out-of-square cuts, verifying your set-up should begin with tools that you are sure about their reliability.

Assuming the measuring tools are as good as you thought, could you check the saw blade with a straight edge for his flatness and wind to rule out wobbling. Also unplug the saw, spin the blade by hand, and sight from the front to scan for any wobbliness.

One last thing to check: Examine your test piece -- is it true, flat and out of wind? If in doubt, use quality plywood as test pieces.

I understand your frustrations...brand new machines should not require a user to go through such frustrating set-up process.

By the way, no matter what you get from this forum, you shouldn't hesitate calling Dewalt for help. They may know a quick fix!

Edit: Do you know the tolerance of your saw? Is the out-of-squareness within the tolerance limit given for your mchine?
Simon

That piece of MDF was definitely not out of flat, and although the edge wasn't jointed (not gonna run MDF through my steel knives, lol), it was pretty much perfectly straight. I'm not sure of the tolerances of the saw, but it's been pretty consistent with both sides, so I'd assume if it can cut perfectly square on one side it should be physically capable of doing it on the other side. To be honest, I'm more frustrated due to that one bolt being in so tight that it caused the end of a torx wrench to have pieces crack off of it! Squaring the machine up on that one side was an absolute breeze and almost therapeutic compared to how I had to square up my old miter saw, so that function gets an easy A+ from me!

I guess I set my expectations a bit too high (I was expecting everything to be perfect right out of the box), and I like having tools that I can recommend wholeheartedly to others (and let them use) with no reservations. The way I see it ending up is that by the time I end up writing a review for this saw, I might have to end up giving it four stars instead of five, much like I did with my $220 Bosch ROS (due to the first friction ring not working as well as I felt it should have). I can tell this saw will be a big help, and I'm sure I'll find some way out of this issue. I certainly hope it's not "just the nature of the beast" (as someone on another forum put it) to only be square on one side, as I love everything else about this machine. Still, no matter how easily this gets resolved, I'm gonna have to put some kind of disclaimer in my review about possibly having to do some careful setting up before the tool is accurate enough for furniture building.

[jasfrank]

What do you mean by “pretty much perfectly straight”? Either it is or it isn’t. Get some wood and joint it perfectly straight and check your results with that. Also set your blade up so you arent cutting all the way down through your wood and make a pass. Is the kerf same as blade width? That will tell you if its the blade. My gut instinct tells me its either a piece of stock that doesn’t have a straight edge or else your blade has teeth hanging out to just one side.

[KingwoodFan1989]

What do you mean by “pretty much perfectly straight”? Either it is or it isn’t. Get some wood and joint it perfectly straight and check your results with that. Also set your blade up so you arent cutting all the way down through your wood and make a pass. Is the kerf same as blade width? That will tell you if its the blade. My gut instinct tells me its either a piece of stock that doesn’t have a straight edge or else your blade has teeth hanging out to just one side.

I mean it was sitting evenly all the way across when I put it to the fence (on either side). It's just not as clean as a jointed edge. Either way, I tested several pieces of different things and got the same results.  And don't forget that my measurements showed the same thing. Blade is out of square on one side but not the other, but the fences are within a few thousandths at worst (same with the table). I'm getting a bit tired, so I'll try cutting only partially into a board tomorrow to check the kerf. Still, why would a blade with uneven teeth result in an out of square cut? All the teeth contact the board at some point or another, so wouldn't it even out?

[KyleD]

Different sides of the fence require different handholds to hold the stock while cutting it. This is a long shot but are you sure the stock is not slipping into or away from the blade by a small bit as the cut is happening? The vibration of the saw can mask this; I have had similar erratic problems using a jig for 45s on the table saw. I could swear I was holding the stock stationary to the fence while cutting but still had small weird errors. My fix was to install some self sticking sandpaper to the fence. Problem solved.

[daddo]

At this point, throw away the devices you are using to calculate if it is square. Make a cut on the left side and calculate how far off you are and make adjustments 1/2 that much and try it again. Do it over and over and shim until it cuts true. One side of your fence or table is off- there is no; "It's impossible".
If you bolt the saw down, be sure the surface is flat. Check all the slides and saw for play- if you use a different hand when cutting, you may be pulling on the saw differently.

[tomsteve]

i had the problem with my DW. pulled the fence off, gave it to my nephew (machinist) to take to work and see what his measuring machines showed.
it was .032 out from end to end of the fence. he took .040 off on whatever machine he used but now i have perfect miters using either side of the fence.

[Roly]

Different sides of the fence require different handholds to hold the stock while cutting it. This is a long shot but are you sure the stock is not slipping into or away from the blade by a small bit as the cut is happening? The vibration of the saw can mask this; I have had similar erratic problems using a jig for 45s on the table saw. I could swear I was holding the stock stationary to the fence while cutting but still had small weird errors. My fix was to install some self sticking sandpaper to the fence. Problem solved.

This was my first thought also.   Try clamping the piece and check results.   Roly Also is the blade square to the fence (the side of the blade) If you place a straight edge on the side of the blade is that at 90 degrees to the fence, not just the saw cut.

[museumguy]

We have at least a dozen Dewalt miter saws at work, all of various vintage and type. At least 8 of them have the same problem. We have yet to figure out why or how to fix them. Those in charge at work, swear by Dewalt. Those of us that use them, swear at Dewalt. Unfortunately, Dewalt seems to be the most readily available saw near us hence why there are so many sold. It's also the reason I have a Hitachi 10" and a Bosch 12" glide.

I'll be following this thread for a possible solution.