[Daniel, Torrey]

We tested an alternate way to hold the piezo in place for the cavity. We glued a mirror to a piezo to a 1/4" thick, 1" diameter spacer (the spacer is required to hold the assembly, the thorlabs piezo is too small). The spacer is then held in place by 3 set screws with nylon tips. See pics below. After realigning the cavity we noticed the quality of the lock is arguably worse (the alignment was much farther off compared to just replacing the piezo). Additionally, the 3.3 kHz resonance is more pronounced. 

In the previous set up, where the SM1 ring and viton o-ring are used to tighten, we found some metal shavings on the viton o-ring. Potentially concerning down the road.