Miter saw tolerance

[Tim Sherwood]

What kind of tolerance do you get from your miter saw? I have a new Makita sliding compound saw. I have been trying to adjust it to make a 90 degree cut. But, the best I can get is .005 from one side of the blade, and .010 from the other. The cuts are less than 90 , from both sides , so I can't average them out. My test board is 11" wide and I jointed the side that is against the fence.

I know that table saws can cut better than this. Are miter saws less accurate?

 

[Joe Scharle]

I have a 15+ y/o Ridgid that cuts on the money. Yesterday, I made a pair of picture frames and never doubted the miters.
The trick is: good blade, never force a cut, rotate/tilt slowly so as not to bend or wear the detents, avoid lazy pulls. IOW, pull the blade in the same line as the angle is set.

When I bought the saw, I could not get a perfect left miter and a right miter w/o adjusting the fence. Since a new fence cost $85.00, and no guarantee it would be plumb, I carefully broke mine and epoxied it straight.

 

[Tim Sherwood]

I agree with your advise Joe . The factory blade on this saw is the best I have ever used. Some of the test cuts have been paper thin and glass smooth. I just can't get a 90 degree cut. I think the design of the fence has a problem. It is a large cast aluminum yoke with two adjustable wings. The wings are machined flat. You can slide them left and right to adjust the width of the throat. Then you lock them down with a knob and screw. But this arrangement means there is a lot of slop in the sliding mechanism. I can easily align these wings with the blade when they are not locked into position. But when the locking screw is tightened, they shift out of line.

I have a call in to the factory techies. Let's see if they agree that a miter saw should be able to cut dead on .

 

[Tim Sherwood]

I have had several discussions with Makita over the past week. I determined that the sliding wings of the fence were not flat. One was out of flat .005,and the other was out by .010. They both sag inwards at the center of the cut line. I asked the rep what they considered an acceptable tolerance. He checked with their product manager and was told that my saw was within specs.

This deviation would double itself when you try to fit a miter joint. That may be OK for job site carpentry. But it leaves a sloppy gap for hardwood furniture.

I thought that would be the end of the discussion. Much to my surprise, the customer service department decided that they did not want an unhappy customer. They said there would be no point in my taking the saw to their nearest service center. They would only be authorized to quote the Company line ; that it's within specs. Instead, they are shipping me a new fence this week. That's how customers should be handled! I'll let you know if that solves the issue.