TS 55 multi-material mitre cut quandary

[Alt]

Hello,

I have reasonably well (-0.01 degrees) squared MFT/3 fence to rail setup.

A mitre cut of a 3/4" birch plywood panel (13" wide including 1" solid birch lippings on each side) shows a strange phenomenon.
The near side (front of the MFT) up to the beginning of far-side lipping is perfect; the far side lipping only, sticks out over 0.5 mm. Needless to say, this becomes a problem over 13".

Interestingly enough, when I cut a panel of the same width, without any lippings, the mitre cut is perfect.
Please see attached picture that shows the far end of the cut with the solid lipping material sticking out!

[attachimg=1]

I'd appreciate any ideas on how to address this issue!

Thank you

 

[Bohdan]

Your blade is blunt. It is compressing the different timbers at different rates producing the step.

 

[Alt]

Thank you for your note!
The saw is barely 6 months old and it has had little use (may 200-300 cuts in all).
These are the first mitre cuts I am trying.
Is it possible that the blade may be have been damaged to begin with?

 

[Bohdan]

Another possibility is that your whole saw it deflecting slightly in a mitre cut because your gibs are not tightened enough onto your track.

This would not be seen in a square cut but as you are cutting the trim at an angle it may appear.

 

[Alt]

The saw is rock steady on the track, both front and back.

 

[Bohdan]

In that case I am running out of ideas.

 

[Roseland]

A couple of years ago I had the same problem, although my wood was not lipped.  I was driven to despair, and tried a new blade and countless adjustments, none of which made any difference.

I thought it might be the saw toe out, such that if I stopped the cut as soon as the cut was complete the back of the blade nearest me hadn’t shaved the cut square.  But continuing the cut until the whole blade had passed the wood showed that wasn’t the problem.

The MFT top showed some slight signs of sagging, so slight it could only be seen with a long straightedge.  I flipped the top over, so that it was if anything slightly crowned.

The problem went away, but I cannot for the life of me understand why or if it was a coincidence.

I would be interested to hear if it works for you.

Andrew