I recently had to change an o-ring on one of my microscopes (~1 year old, some 50 - 100h of use) after noticing that the mobility on the x-axis was not quite proportionate. At first I did not think it was an o-ring issue since the o-ring was still intact.
After cutting off and replacing the o-ring, proportionate x-axis mobility was restored. When comparing the old o-ring with a fresh one, the malfunctioning o-ring had gotten ~2cm longer.
This extension leads to a loss in “pulling”-power would explain the lack of mobility in that direction (compressed actuator, negative x-axis movement), if I understand everything correctly.
This made me think. To minimize tear and extension of the o-rings, would the optimal resting-position of the microscope (when not in use) be when there is the least tension on the o-rings? This would then be when the actuators are compressed (negative direction). Until now, I try to leave my microscopes in a middle position (leveled actuators), to minimize tear on the plastic. But this might be completely unnecessary and also seems to be sub-optimal with regards to the o-rings.
So I wonder, is there a recommended position for when leaving the microscope resting taking both plastic and o-ring tear in consideration? Excuse me if I have overlooked some existing recommendations in the documentation or here in the forums.