Looking at my servo’s when I manually run pan(90) then pan(-90) or tilt(90) then tilt(-90) its not 180 degree’s.
Its Chinese servo specs as the pulse width 400 to 2800 just doesn’t equate to what is stated as a full travel of 180 degrees.
From reading the tinternet what would seem to be strange is that not all TowerPro SG90’s are equal.
So if you would run a little program.
from pantilthat import *
pan(90) #Next run change to -90
tilt(90) #Next run change to -90
Out of interest what real travel are you getting I haven’t physically measured the angle but it isn’t 180 and its not gimbal limits or stops.
At a guess I am getting 145 but wondered how much difference we all have or are we all getting approx that?
Same out on the web where they seem to be getting more, but still not 180.