Not another "which tile cutter" but...

[monkey3]

They're a pain in the back side when they don't cut straight.

That they certainly are!!!

Lift the blade right up if you can and just cut into a tile about 1mm to 2mm deep... then take measurements from tile edge to see how straight a line it has cut... if this is true then you have blade or head unit wander when cutting full depth.. a thicker blade can combat this but some times it is the flange holding the blade that allows the blade to wander.

Unfortunately there's no ability to lift the blade on this tool. But I did run the blade along the a known straight edge which I used to adjust the back stop and it was pretty much bang on. Then when I cut through the tile, in the space of a 400mm tile, it ends up anywhere between 4 and 8 mm off.

It's going back tomorrow anyway, I think I'm going for the Rubi ND200.