So I had my original 6mm belt on my x axis break. So I decided to go with the 3GT (GT2-3M) Timing Belt from open build parts and the 20t timing pulleys. Will there be any major recalibration? Or just some fine tuning?
3mm pitch and 20 teeth is 60mm per rev (200 steps before microstepping) so your theoretical steps/mm changes (assuming 8X microstepping) to around 26.667 steps/mm from the 40ish.
Definitely need to fine tune that but it gives you the ballpark starting point.