Yes, in looking at optical point-track system stability in an aircraft external pod rocking-mode situation. It was easier to design a fixture with a pivot at one end and a pivot over the shaker head. Then translational shaker motion creates uniaxial rotary random motion, which input into the optical system stresses the stability control algorithms/hardware. To prevent simultaneous correlated translation (if desired) you have to mount the payload at the stationary hinge. Note all this was done in the preliminary design phases on paper/computer sim. What was ACTUALLY done and the experience was the province of the engineers who stayed with the program.
