What am I doing wrong!?!

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Forum topic by surfnsd posted 02-24-2016 03:33 AM 1463 views 0 times favorited 35 replies Add to Favorites Watch
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7 posts in 247 days

02-24-2016 03:33 AM

Topic tags/keywords: question help milling square

In my last few projects Ive encountered this problem and its driving me crazy because I cant seem to figure it out. I’ll try to explain it as best I can but Im not even sure I can explain this. I use the standard method of milling my boards by using my jointer, then table saw. After jointing a side I take it to the table saw and rip the board making sure to keep my jointed edge against the fence. I then use a crosscut sled to square one side, then I flip the board keeping the same edge against the fence of the sled and crosscut the other end of the board. I do this mainly because I don’t have a decent miter saw. But then this always happens. When I go to cut a tenon I find that the board is not square to the fence when I flip it upside down, and thus the cuts are off. Refer to the pictures, but when I have the jointed edge down the board is square to the fence and I make a nice straight square cut. When I flip the board over to cut the other side all the sudden im about 1/32 off square and the cut isn’t parallel. Sorry if this is confusing, but Im trying to explain it the best I can. What am I doing wrong!?

Ive checked everything possible. The blade, fence, and crosscut fence are all square and parallel to each other. I have no clue whats causing this but its obviously something Im doing wrong. Any help or advice would be greatly appreciated.

This is with my jointed edge against the sled. As you can see the board is square with my fence.

I then flip the board and I get this gap which obviously isnt square, and then makes the cut off.

This is the result.

35 replies so far

View Woodchuck2010's profile


465 posts in 281 days

#1 posted 02-24-2016 03:38 AM

I’m not positive, but it seems as though your blade isn’t parallel to the table.

-- Chuck, Michigan,

View DirtyMike's profile


384 posts in 325 days

#2 posted 02-24-2016 03:52 AM

have you used a dial indicator to check all of your tolerances? I am with woodchuck on the blade not being parallel ,

View MadMark's profile


970 posts in 876 days

#3 posted 02-24-2016 04:08 AM

That looks ike an Incra miter gauge. If your rip fence is out you can wind up with a nice taper. Get rid of the sled and see if that clears up the issue.


-- Madmark -

View mahdee's profile


3465 posts in 1190 days

#4 posted 02-24-2016 04:33 AM

Your saw blade is not at a 90 degree to the board although it might be at a 90 degree to the table’s surface. To test this, make a full cut on a scrap 2×4 on the sled, flip it over and raise the blade all the way up a see if the cut you made is at 90 degrees to the blade.


View bandit571's profile


14084 posts in 2106 days

#5 posted 02-24-2016 04:42 AM

Actually… the crosscut to make the end square…..blade has a very slight tilt to it. like maybe 2 degrees, maybe.

So, one face would be tight against the fence, but, when you flip it over, you will get that gap.

As said above, run the blade all the way up. Take a GOOD square, sit the fat side on the table’s top. slide the square over to the blade. DO NOT touch the teeth. Touch only the “plate” of the blade. Have a light shining from behind the square. Look along side the saw plate, see IF there is a gap. Adjust the saw’s bevel until the gap is gone.
Then try the same cuts, using some scrap wood. See IF the cut has improved.

-- A Planer? I'M the planer, this is what I use

View Rick M.'s profile (online now)

Rick M.

7727 posts in 1803 days

#6 posted 02-24-2016 06:49 AM

2 things come to mind, 1) the fence is not parallel to the blade so opposite sides are not parallel. or 2) You have a saw with the alignment problem (4512, etc.)


View Slemi's profile


102 posts in 964 days

#7 posted 02-24-2016 09:49 AM

100% sure the blade isn’t the problem. If the blade would not be in line with cut the cut would still be square, just a little wider.

The problem is the fence, You have to adjust the fence to be in line with the miter slot!!! This is the first thing to do, before adjusting blade or miter fence!!!

After You correct the fence, then get the miter fence square to the fence.

Just slide the fence on the miter slot and see how out of line it is.

View Tony_S's profile


598 posts in 2506 days

#8 posted 02-24-2016 11:01 AM

If the ripped board has perfectly parallel edges, the only issue I can see would be your crosscut sled. It’s not truly 90 degree’s to the blade or fence.(assuming the blade and fence are parallel to each other, and the miter slots)

Is the gap always at the rear of the cut once you flip the board? If so….your sled is effed.

Test for you to confirm without a square(squares aren’t always square)
Take a piece of scrap your sure has parallel edges and mark a pencil line all the way across one edge, and crosscut with your sled. Take the two pieces and place one on the tablesaw top,pencil edge down. Rotate the other piece so the pencil edge is up. Butt the two cut ends together….is there a gap top or bottom? If so…your sled is effed.

-- It is the mark of an educated mind to be able to entertain a thought without accepting it. Aristotle

View surfnsd's profile


7 posts in 247 days

#9 posted 02-25-2016 03:40 PM

The saw s a brand new SawStop cabinet saw. I bought a needle gauge today and will check all my specs. I checked the fence last night with the little time I had. I zeroed the needle at the rear of the fence and it measured 0.00 at the far end of the fence from the miter slot. There was about a +0.06 change at the worst at some parts of the fence along the way, but I was told that as long as the rear and far edges measure 0.00 on the gauge then you should be good to go?

Also I made a few cuts with the miter gauge that came with the saw and got the same problem.

View Slemi's profile


102 posts in 964 days

#10 posted 02-25-2016 04:57 PM

Today I took another look at your photos. It looks like the miter fence is not square.
Try this:
1. Check the board has parallel sides (equal width along board).
2. Cut the board “square” with miter gauge.
3. Flip the board along the side (not sure how to explain, just put the opposite side of the board against the miter fence).
4. Cut some piece from the end of the board 1 inch would be good.
5. Measure “front” and “back” of the cutoff and see if they are the same. Here You will see the difference and while there is difference here, the miter fence isn’t square to the slots/rip fence.

View MrUnix's profile


4039 posts in 1622 days

#11 posted 02-25-2016 04:57 PM

Also I made a few cuts with the miter gauge that came with the saw and got the same problem.

Sounds like you need to align the table to the blade. The fence can be dead nuts parallel with the miter slot, but if the miter slot isn’t parallel to the blade, it will always be off.


-- Brad in FL - To be old and wise, you must first be young and stupid

View bearkatwood's profile


1173 posts in 434 days

#12 posted 02-25-2016 06:19 PM

The table top is on crooked most likely.

-- Brian Noel

View bandit571's profile


14084 posts in 2106 days

#13 posted 02-25-2016 06:30 PM

Sooo, have you at least checked the blade to see iF it is a perfect 90 degrees to the top’s surface?

Start with that, sometimes, a simple fix is all that is needed…

-- A Planer? I'M the planer, this is what I use

View Slemi's profile


102 posts in 964 days

#14 posted 02-25-2016 06:38 PM

...if the miter slot isn t parallel to the blade, it will always be off.

- MrUnix

This is right

View Marlow's profile


116 posts in 2094 days

#15 posted 02-25-2016 06:53 PM

I wrote a short blurb for Fine Woodworking about this issue a few years back. Using the miter gauge, a square cut depends on the relation of the miter gauge fence to the line of travel of that fence. If your miter gauge bar is straight, and lets say references off the right side of the miter slot, the miter fence needs to be square to the right side of the miter bar. The miter gauge calibration could be off, and you could play with adjusting it to see if you can eliminate the problem. I have also found that some PSA backed abrasive paper stuck to the miter fence helps hold the work against the fence while eliminating the possibility of the work sliding along the fence as you make the cut. You may want to try that as well. An out of square blade could certainly impact the quality of the cut, but all else being equal, it should not impact the squareness of the cut. Your rip fence should not even be part of the discussion, since you are performing a cross-cutting operation.

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