DeWalt 12 inch miter saw miter cuts are off.

[ABBEY thomas]

When cutting 6 inch wide boards for a jewelry box, my miters are off almost 0.025 thousands. Replace trunion and pin to no avail.. Armature bearings are tight and can't figure whats wrong. Saw is set at 90 degrees ( motor unplugged) and slowly bring the arm down, it goes off about 0.06 degrees. Not good for miters.
Dewalt says take to their repair shop. Has anyone had this problem? Thanks.

[Patrick Walsh]

It’s a miter saw and a 12” blade at that. If you can get dead nuts miters off any 12” mitersaw well you a wizard.

[Richard Coers]

Agree with Patrick, 12" miter saws are for building decks and not precision joinery. I use a tablesaw sled for box making. Could be your blade is dull too. Switch to a new blade and see what happens.

[Frederick Skelly]

Is this a new problem? Did it ever cut better than this? If not, taking it in for service may not help.

It doesnt fix your saw, but it would fix your miters - you could cut the miter on your cms, then use a hand plane and homemade shooting board to dial-in the miter. I have a 12" cms and routinely do it this way.

Hope you get it solved.
Fred

[Zachary Hoyt]

I cut miters on the bandsaw mostly, but it's the same principle. I always seem to have to do a little extra work to fit them exactly, and I use the 12" disc sander on a Shopsmith for the job.

[Bill Dufour]

I pull the handle to one side as I cut otherwise it can go either way a fraction. If it is consistent you need to adjust the angle stop and/or clean the mating surfaces. They often get gunked up or rusted.
Bil lD.

[Edwin Santos]

I was using my 12" DeWalt CMS for picture framing and needed the cuts to be accurate and they were not. What I did was take a scrap piece of 1/4" MDF and hot glued it to the table and adhered sandpaper strips to it, clear of the blade, under where the workpiece would be. Problem solved.
It appears that what was happening to me was slight movement of the workpiece affecting the cut accuracy. The sandpaper sub-top firmly held the workpiece from moving. When done, just pop off the sub-top and remove any hot glue with denatured alcohol.
Hope this helps you, but if it's a dead end, at least it will be a cheap and quick one.
Edwin

[Clifford McGuire]

I've gotten in the habit of touching up my CMS cuts with a shooting board. It takes an extra couple minutes, but they are dead on.

[Ray Newman]

"I've gotten in the habit of touching up my CMS cuts with a shooting board."
--C. McGuire

BINGO!

[glenn bradley]

This is a common problem. There are some folks who claim suitable accuracy from a chop saw. I use one every couple of years to trim out a bathroom or kitchen and they are great for that. A well aligned, good quality tablesaw is king for accuracy IMHO.

[Patrick Walsh]

I agree with a tablesaw sled.

However I’m curious. I have run into a number of occasions where I shoot board seems appropriate.

My question is how do you get exact length matching parts as to obtain perfectly square. All I can figure is count cut everything together with a scale on whatever saw them count your strokes. Or get one end good then like any other saw make or set a stop for and or on the shoot board..

I’m talking like exact as if off a machine calibrated properly. Not good enough for for exact..

[Mel Fulks]

I've had good luck using coarser saw,slowly. Helps make up for the fact that one side of saw is cutting with grain, while
other side is cutting against.

[Alex Zeller]

I've never got accurate cuts on my DeWalt. I now use an Incra 1000HD to cut shorter pieces. Since it has a stop I can cut the exact same length pieces easily. If I have to use my CMS I make a full length line and Just apply sideways pressure to get the saw to follow the line. Years ago I had a 15" Makita non compound or sliding miter saw that was extremely accurate. But it was mostly steel and weighed a ton. Setting it up to use was more of a pain so I gave it away. I do miss it.

[Doug Dawson]

It’s a miter saw and a 12” blade at that. If you can get dead nuts miters off any 12” mitersaw well you a wizard.

The OP doesn’t say _which_ miter saw it is. The cuts from my DW780 are dead nuts square, as far as the eye can see without a loupe. So the saw is capable of that with proper setup, and I don’t think I’m a wizard, last time I checked (although doors still do open before me sometimes if I hold my hand out.)

[Patrick Walsh]

Saiz right in the title “Dewalt 12” mitersaw”.....
Or maybe I have lost my mind.

But if you wanna argue I got time today.

I’m kidding but,

I’ve been building crap with miter saws for 20-25 years. I’ve never gotten reliable repeatable cuts at 90% both plumb and cross in any material I throw at the saw ever on either side of the fence.

Here and there maybe, but if you did or do great, but it has not been my experience and it’s pretty much common knowledge of anyone who builds stuff for a living that chop/miter saws are notoriously unreliable for reliable perfect cuts at any angle.

But again if you are doing it my opinion would be Your one of the lucky ones. Or you got bad eyes or low expectations or you dropped your square one to many times...


The OP doesn’t say _which_ miter saw it is. The cuts from my DW780 are dead nuts square, as far as the eye can see without a loupe. So the saw is capable of that with proper setup, and I don’t think I’m a wizard, last time I checked (although doors still do open before me sometimes if I hold my hand out.)

[Robert Hazelwood]

I agree with a tablesaw sled.

However I’m curious. I have run into a number of occasions where I shoot board seems appropriate.

My question is how do you get exact length matching parts as to obtain perfectly square. All I can figure is count cut everything together with a scale on whatever saw them count your strokes. Or get one end good then like any other saw make or set a stop for and or on the shoot board..

I’m talking like exact as if off a machine calibrated properly. Not good enough for for exact..

I suppose you could use stops on a shooting board. But mostly, once you are close, you just take a shaving or two and then compare the two pieces. If one is longer take a few more shavings on it. Your fingertips can tell a 0.001" difference in length. Each stroke is removing only a thou or two so it's not too difficult to get it right, just slow.

[Robert Hazelwood]

With mitersaws one thing to always check is the reference surfaces (table wings, center insert, and fence). If these are not flat/coplaner you cannot count on consistent results. Different size parts will behave differently with respect to the blade.

Miter saws may not be the ultimate in precision cutting but I think most can get considerably better than 25 thou out over a fairly small workpiece.

[Doug Dawson]

Saiz right in the title “Dewalt 12” mitersaw”.....
Or maybe I have lost my mind.

But if you wanna argue I got time today.

Um, they make more than one. The one I have meets expectations for a “fine-woodworking-grade” crosscut, that rivals what you could expect from a decent table saw. That’s not something I’m going to argue, it’s an observed fact (and I probably have better measuring tools than you do. :^)

It’s up to you to “argue” that it’s impossible, and you can do so til you’re blue in the face, because it’s not. :^b

Yours in bemusement...

[Anuj Prateek]

When cutting 6 inch wide boards for a jewelry box, my miters are off almost 0.025 thousands. Replace trunion and pin to no avail.. Armature bearings are tight and can't figure whats wrong. Saw is set at 90 degrees ( motor unplugged) and slowly bring the arm down, it goes off about 0.06 degrees. Not good for miters.
Dewalt says take to their repair shop. Has anyone had this problem? Thanks.

I have a DW716. Cuts used to be way off before I squared it. Incidentally, I changed the blade today and resquared it. Well to the best of my ability, using a machinist square and feeler gauges.

Tried some 90° and 45° cuts and they came out pretty accurate. I would say 1/64" over 4". I don't expect it to do any better. Keeping the wood rock solid so that it does not creep during the cut is difficult. And then there is blade deflection towards end of cut. Or, some dust that gets trapped between wood and platform.

I prefer to tune up the cut using shooting board now. I find it simple compared to chasing the accuracy on the saw.

If not once in a while 4x4 and 2xX lumber, I would sell it off. Takes too much space and serves too little purpose, for me.