Weird issue squaring mitre saw

[solexious]

I'm trying to square the bevel on my mitre saw, but rather than any slant being mirrored on both sides of the cut like \\ or //, when I get as close to 90 as I can, I end up with a slight /\ cut. I've marked an exaggerated version of what I'm seeing on the cut:

So far I've checked the blade is tight and not wobbling, that my square is square I'm checking with, tried with different wood to check its not some oddness with that.

Any idea whats going on?

Cheers

Sol

 

[Kayen]

It sounds like the bed of the saw isn't flat - it's probably angling down from the middle. Put a straight edge across it to check. You should be able to fix it using a packed, flat over-base.

 

[solexious]

It sounds like the bed of the saw isn't flat - it's probably angling down from the middle. Put a straight edge across it to check. You should be able to fix it using a packed, flat over-base.

I've checked the metal bed and it seems to be flat, I can't see any light coming through, but the plastic insert in the center does sit slightly lower than the metal, could that be it? If so should I pack up the insert from below with washers or something?

 

[johnnyb]

You find with these saws occasionally the head travel and the blade aren't properly aligned. When a blade is forced into a piece of wood slightly skewed it can still cut ok but it does lead to odd cut effects. To check take a widish plank and plunge in like a non slider. Then without moving cut the outside to 5 or 10mm of the first cut. These should be perfectly in line.

 

[johnnyb]

And just to say when there perfect everything seems to cut easier and safer. Even with non sliders. Of course some saws just won't align...