This page illustrates one of the ways to make automate motion of a lens nount. I came up with this idea, when I learned that very shortly I would need to perform a large number of measurements, where precise changing of a position of the lens was needed. We couldn't buy any motorised mount that fast, so I designed the parts and had them made for me on our faculty's mechanical workshop.

The mount was very usefull: by changing the the lens position I was able to change a place on the sample, that was placed in a liquid helium cryostat, where I performed photoluminescence measurements in function of a magnetic field and a detuning (something dependent of the place on the sample, and therefore lens position).

The mount was made of aluminium and I purposefully used rather small stepper motors, so that they would not be attracted by cryostat's magnetic field (which otherwise could result in slight bending of the mount and therefore affecting lens possition and orientation). Other than aluminum chasis, the mount requires the shaft connecting stepper motors with the precision screw driving the lens. It is needed to make up for any misalignment of the screw and the stepper motor. This part was custom made out of teflon, and worked like a charm.