DeWalt 12 inch miter saw miter cuts are off.

[ABBEY thomas]

I have a DW 716 , 12 inch double bevel miter saw. I am losing around a 0.5 degrees on my cuts. I can't make small boxes due to the angle is off. On a 6 inch wide piece the cut is off around 0.030 inch. I replaced the pivot pin, trunion housing and the table nylon bearing and cut is still off. checked for play in the motor and appears good.
Has anyone else have this kind of problem? I know of another craftsman with it. Any help or suggestions will be greatly appreciated. Dewalt only says to take it to a repair shop, what for another $150.00.
Thanks, Abbey Thomas

[Robert Hazelwood]

If the cuts are inconsistent check fence and table for flatness. In particular the plastic blade insert which is often a bit low. On my 716 I replaced that with an MDF insert adjusted so that it was coplanar with the table on either side of the turret.

If those surfaces are not flat/coplanar then parts will sit at different angles to the blade depending on their length or where you are applying pressure.

If the registration surfaces are flat and the cuts are consistent, but consistently off, then it seems you just need to bring it into square. There are little microadjusters near the turret locking lever, and the bevel angle can be fine tuned by adjusting the stop screws.

Unless there is a lot of slop in the pivot arm or table I'm not sure what needs to be repaired. There will always be a little play in these lightweight saws, but mine is on the order of 0.005 to 0.010 when trying to move it side to side with moderate pressure, registering a dial indicator on the blade. It's less in use when I'm not trying to make it move side to side.

[Eric Schmid]

If you are making these cuts with the face of the board flat on the table as opposed to standing up against the fence, you’re working against physics. The angle of approach and diameter of the blade lead to deflection in the cut.

There are better ways to get perfect miter cuts in wide material. Standing material up against the fence and using the carousel to miter is one, but limited to the capacity of the blade. Bevel on the table saw for similar reasons works very well and can be used for long miter cuts. This angle of approach causes much less deflection.

Your saw can be adjusted and tuned. When I tune my saws I do so to within 0.002. I do not expect any of these 10”-14” blades to give that kind of accuracy with the head tilted at 45 degrees. The approach angle of a sliding saw is also better when cutting on the flat, but it’s still asking a lot of a job site machine.

A few things you can do to mitigate. Start your saw tuning from the beginning. For me that’s flat table, zero clearance insert, flat fence square to the table, sharp full kerf crosscut blade. Now you can measure for adjustment of bevel and miter.

A shooting board and hand plane can be very helpful in final adjustment of angles.

[Zachary Hoyt]

I've yet to see a miter saw that has seen much use that has a perfectly straight fence. They all seem to be a bit (or substantially in some cases) dished in in the middle, so that the two halves of the fence are not quite parallel.

[Mike Cutler]

How are you setting your saw up for the angles? Did it used to work doing this type of cut?
Are you using the built in protractor, or an angle gauge?
I have always found the OEM protractor, with locking detents to be "close", but not perfect. I typically use a good Angle gauge to check at 90,60,45 and 30 degrees.
Generally I can get things pretty darn good, but it takes some time.