Dado not lining up

[Alex Bowler]

Hi

I have a problem when i do units involving dados, they all ways seem to be a little bit out. At first thought this was
due to the fixture offset not being set correctly but i have since dialed it in and the dado are not constantly off in on direction.
Sometimes they are perfect sometimes they are 0.3mm out at worse they are about 0.5mm out.

I have set the timing feature to trim 5mm off to ensure board is square, I have also ensured my tool dia is correct.

I am running e cabinets and THM desktop in metric mode and i was wondering if that might be the problem
as it is only out by so little. Has any one else experience this or have any idea why?