[3D Grandpa]

I'm having an issue cutting with my miter saw. I'm trying to cut angles, but then they don't match up. I thought my blade was flexing, but doesn't matter what brand of blade, or how expensive it is. I've started a little side business making custom benches and this is driving me crazy. The only cut that is dead on is a straight cut. Could the markings on my saw be off??? Is there something I'm doing wrong?? Any help or insight would be greatly appreciated!!!

 

[Woodworker171]

When you say the angles are off what do you mean?

 

[JohnnyG73]

I'm no expert but I have heard that you really shouldn't trust the factory degrees of a saw...90, 45, or whatever. I'm not sure if your "tilting" or "turning" your miter saw. If you're tilting it you can use one of those magnetic angle finders to check the angle. If you're turning it you should check the angle of the blade to the fence.

One last thing I can think of...the miter saw should have some kind of stop that prevents the blade from cutting the saw itself in half when you bring it down. If that stop happens to be at an angle it could be causing the blade to shift when it bottoms out.

Again, I'm no expert and I'm sure there are people here that can give you a better idea what's wrong.

 

[Noek]

You should list brand, manufacturer, etc of the saw and blade to give people a better idea of what you are dealing with. Perhaps someone has a similar saw/issue that you are dealing with.

Just for kicks, I would run through the whole setup of the saw again from start to finish.

 

[GoNavy429]

You'll have to give us a little more info, like what kind of saw, maybe a picture of the box or frame or what it is your making, are you end cutting, or trying to make a frame, compound angle cut etc...just saying you angle don't match doesn't give us much to go on...:laughing:

 

[3D Grandpa]

When you say the angles are off what do you mean?

If I cut some 45 degree angles, when I match them up, there is always a gap. An example of this is if I'm doing trim.

 

[Gene Howe]

You can use a draftsman's plastic triangle to adjust your saw to 45 deg.
One other tip: Cut on one side of the blade for one 45 and cut on the other side for the mate. Guaranteed to fit as they are complimentary angles. Even a degree or two off won't matter.

 

[GoNavy429]

If I cut some 45 degree angles, when I match them up, there is always a gap. An example of this is if I'm doing trim.

So are you saying when you put the two boards together it does not make a 90 degree angle unless you open up the inside/outside portion causing a gap. Is it less then 90 or more then 90 when you push them together or is the gap in the middle of the miter. A picture sure would help.

Most saws have a stop for 45 degrees, if it is off there, it is most likely off when set to zero. Are you sure that the straight cuts are indeed 90 degree cuts. You may need to re-align your saw to square then your miter will come out correctly.

 

[Oneal-Woodworking]

So are you saying when you put the two boards together it does not make a 90 degree angle unless you open up the inside/outside portion causing a gap. Is it less then 90 or more then 90 when you push them together or is the gap in the middle of the miter. A picture sure would help.

Most saws have a stop for 45 degrees, if it is off there, it is most likely off when set to zero. Are you sure that the straight cuts are indeed 90 degree cuts. You may need to re-align your saw to square then your miter will come out correctly.

When I am doing doors or something (LOTS of 45 deg cuts) that are mitred - I will use two saws and lock each down once set up correctly.

One for the left 45 and one for the right... :yes:

 

[GeorgeC]

I'm having an issue cutting with my miter saw. I'm trying to cut angles, but then they don't match up. I thought my blade was flexing, but doesn't matter what brand of blade, or how expensive it is. I've started a little side business making custom benches and this is driving me crazy. The only cut that is dead on is a straight cut. Could the markings on my saw be off??? Is there something I'm doing wrong?? Any help or insight would be greatly appreciated!!!

Do not trust the angles marked on the saw. As the saw (regardless of brand) comes from the factory these could be off.

Get a known angle to measure against. One of the best and cheapest is a set of draftsman triangles. These are relatively cheap (made of plastic) and accurate.

George

 

[Bonka]

Angles

When I do miters, e.g. 45d, I always use my 45d shooting board. If I cut a 90d I use my 90d shooting board.
This has saved me untold time & frustration in trying to set a SCMS to be exact no matter how I fret over its adjustment.
I have a reasonable good DeWalt 12'' SCMS that I bought many years ago and have had no trouble with it. I often times get perfect cuts from it. It seems, to me, that wide swings in temperatures have an effect on precise accuracy.
I have never had a problem with fit ups when fine tuning with one of my shooting boards,

 

[GoNavy429]

When I am doing doors or something (LOTS of 45 deg cuts) that are mitred - I will use two saws and lock each down once set up correctly.

One for the left 45 and one for the right... :yes:

Before you do anything else you will need to find which saw is off, the easiest way I know is to take a piece of flat stock like 1x2 or 1x4 make a 45 degree cut, take the remaining piece and flip it over,then put the two pieces together and check it with a framing square to make sure you have a 90 degrees. If you don't that saw needs to be aligned. One or both might be off. What type of trim are you cutting, because if it's crown there is a bit more complexity to this then just making a 45 degree cut. For crown you will need to make a compound bevel cut.

edit: Man I need to start paying attention to who the OP is...lol...just ignore this OnealWoodworking, 3D Grandpayou can do this on your saw to check for square

 

[3D Grandpa]

Thanks for everyone's input. The saw I have is a 10" Delta. I'll do some playing around and try some of these suggestions.

 

[3D Grandpa]

When I do miters, e.g. 45d, I always use my 45d shooting board. If I cut a 90d I use my 90d shooting board.
This has saved me untold time & frustration in trying to set a SCMS to be exact no matter how I fret over its adjustment.
I have a reasonable good DeWalt 12'' SCMS that I bought many years ago and have had no trouble with it. I often times get perfect cuts from it. It seems, to me, that wide swings in temperatures have an effect on precise accuracy.
I have never had a problem with fit ups when fine tuning with one of my shooting boards,

What's a shooting board????

 

[amckenzie4]

What's a shooting board????

A shooting board is a device for truing up miter cuts using a hand plane. It generally consists of two boards and a fence: one board sits flat on the bench. The second is glued to the top of it, lined up so that it's flush on three sides, but leaving three or four inches of the first board visible on the right side (left side if you're a lefty). The fence makes a 90 or 45 degree angle to the first two. To use it, the plane is set on its side, running along the edge of the second board, with the workpiece set against the fence.

There's a good video

, and a much longer one

.

I've finally gotten my bench hook squared up enough that I can use it as a simple 90 degree shooting board, and it's amazing the difference it makes. I cut as close as I reasonably can, and take a few passes (or more than a few, if my cut is way off...) after which I have a perfectly square end on my board, and cut remarkably smooth.

 

[GoNavy429]

A shooting board is a device for truing up miter cuts using a hand plane. It generally consists of two boards and a fence: one board sits flat on the bench. The second is glued to the top of it, lined up so that it's flush on three sides, but leaving three or four inches of the first board visible on the right side (left side if you're a lefty). The fence makes a 90 or 45 degree angle to the first two. To use it, the plane is set on its side, running along the edge of the second board, with the workpiece set against the fence.

There's a good video here, and a much longer one here.

I've finally gotten my bench hook squared up enough that I can use it as a simple 90 degree shooting board, and it's amazing the difference it makes. I cut as close as I reasonably can, and take a few passes (or more than a few, if my cut is way off...) after which I have a perfectly square end on my board, and cut remarkably smooth.

What stops the bottom of the plane from planing off the shooting board, seems like after awhile it would be off, or is there a special plane used, maybe I am missing something, looked like a normal plane. I have never used one, looks interesting. I have a plate sander on my shopsmith, and have always sanded miters off a jig I made butted up again the fence, my plate sander moves like a horizontal drill press to the work piece.

edit: Never mind, watched the second video, I see how it works now. Little shoulder stops it from eating away the shooter board. Very cool may have to make one of these.

 

[johnnie52]

A 10" Delta is a great saw and mine always made dead on accurate cuts no matter the angle. I miss it every time I try to use the new Kobalt saw I bought to replace it when it finally gave up and died.

There is one other thing that will cause your corners to have a gap. The boards absolutely must be perfectly equal in length. Even having one board less than 1/32" longer or shorter than its opposing board will cause a gap at the corners.