Mitre saw cutting path

[Lol999]

Hi, got a slightly curious one. I have a Metabo 216mm sliding mitre saw. Apart from the fact it needs regular adjustment to stay true it cuts well, all except when on a 45degree cut.
Cut a 45 degree mitre on some 6" skirting board and there's a pronounced arc of the path before it straightens out.

Everything seems tight and secure so I'm a bit lost as to where to start.

Suggestions?

 

[Deleted member 174758]

Is your skirting cupped? (common flaw especially with softwood) Are you supporting the full length of the skirting properly?

 

[catlad]

A spinning blade can't cut curves

 

[Deleted member 174758]

Nice theory. On that basis a saw blade on a table saw would never be able to hit the blade opening insert. Buy they can, and on the odd occasion, do just that. Worst offenders (in mitre saws) are the big 12in saws where the blade can visibly flex if making a cut where one side of the blade is in the material and the other isn't (e.g. a dust cut). The other thing you can get, especially if bevel cutting is flexing or bowing in the arm of the saw as the head moves outwards

 

[catlad]

Ok well I have 4 mitre saws and 3 circular saws and I have yet to come across any of my saws cutting curves, Although I don't own a 12" saw.

 

[johnny2007]

Don't press the blade on the wood.
Let the blade cut slowly so it doesn't flex.