Precise 45-degree cuts are nothing easy with a tracksaw.

But the scale is not the critical piece. Way more critical is that the track is (and has to be) slightly elastic. While desirable for clamp-free vertical cuts. The flex from the rubber strips affects angle repeatability and means that while one definitely needs to clamp, clamping too much is bad as the rail bends and is not 100% co-planar with the material where the clamp is.


Based on your out-of-square comment at 90° from factory /did not hear of that for Festool/, I suspect you apply sufficient pressure to change the rail position. This can affect 90° but even more so the 45° cuts "position" on the scale.

I would advise to try below:

- place the rail and clamp it, but only so much the rubber strips touch the material and only slight pressure is applied, the metal ribs around them must not touch the material where clamped - i.e., the rail must not be bent at the clamp
- when riding the saw, use your left hand placed on the saw base, ensuring it does not flip BUT putting only minimal pressure by the saw on the rail, the rail must be absolutely flat on the surface, but must not be pushed "into" the material with your right hand either. Any vertical pressure applied causes angle change as it forces the rail to flex. You have to use screw clamps for this, fast clamps don't work here as they are too "rough".

Do a couple cuts like this - testing repeatability and, when you check the angle:
 - make sure you have a precision 45° square, not just estimating it
 - check the angle on multiple points of the cut to ensure consistency
 - if you are checking using 2 pieces against a 90° square, just a reminder, the material is slightly mushy, so 45° may not look like 45° ...

It is very very easy to "align/tune" the saw to the "beginning part" of an angle cut which can be skewed from a too-tight clamped rail and mess the rest of the cut by it. And it is even easier to push the saw too much, causing the angle to change sufficiently to be an issue during the cut.


Secondarily, for 45°, the scale is really only orientational. That is not about the accuracy of the scale though.

The mechanics of the rail-saw combo during an angle cut heavily depend on how the rail is attached/fixed AND even more so on the pressure (and the angle of the pressure) applied. This means that the same saw in two different hands can make slightly different angle cuts. All the way +/- 1° difference.

How would I know ?
Well, I managed even a 2° difference when first using my TSC 55 ... 

Eventually, I ended up dedicating one Makita 1500 rail with the anti-slip strips removed for angle cuts. That makes that rail useless for vertical cuts but being "hard" it does not flex on the angle cuts. Also the Makita anti-splinter is soft, this makes it crappy for its official fucntion, but it is very good at "giving way" at low saw pressure and not compressing afterwards.

if i bought a new festool tracksaw and 90 was not perfect out of the factory i would exchange it immediately and not be doing any calibrations to begin with

also chat with the people at the store. since you're new with the saw it's also possible you are doing something non-obvious while using it