In OpenFlexure Connect, I understand that each increment in the x, y, and z directions correspond to a movement in the respective stepper motors. I was wondering for the Delta Stage, would anyone happen to know the approximate dimensions that the arbitrary units in the OpenFlexure software correspond to in micrometers?
There are approximately 4096 steps per revolution of the small gear connected to the stepper motor. 2:1 gearing gives about 8200 steps per revolution of the M3 drive screw in the actuator, which has a pitch of 0.5mm. So about 60nm travel in the actuator per step. This is the same for all of the different versions of the OpenFlexure stages. Then there is a lever ratio on the stage motion. This I don’t know exactly, I think the vertical, z, motion has a ratio a bit less than 1, so a bit less than 60nm per step in z. In x,y the stage the gear ratio is more than one (1.5 or 2?) so maybe 100nm per step?
I feel that I have missed a factor of 2 in here, because the microscope is quoted as 70nm in x and y.
The microscope moves with accuracy 70\: \text{nm} in x and y direction and 50\: \text{nm} in z direction. To convert pretty accurate micron to step I use formula (u \cdot 1000 )/62, where 62 \:\text{nm} / \text{step} is very good approximation.