This is a vacuum base for my Quick Adjust Vise, but I've also included the STEP file for the ball & socket part on top so that you can adapt it for other applications. Just press the vise against a smooth surface, lift the lever, and slide the handle latch into the notch on the base. The TPU bottom membrane, printed in TPU (I used 95A durometer Ninjaflex), sticks really well to smooth surfaces like glass, but can lose suction more quickly on textured surfaces. Softer TPU would be more conformal, but more difficult to print.

Pro tip: I stuck a soft rubber sheet to the bottom of the membrane with double-sided tape, which improves the suction duration.

Printing
The bottom membrane is printed in TPU. I used 95A durometer, but softer might work better. All the other pieces are printed in PLA. No supports are needed. Note that the ball and nut print together as one piece. Also note that the base has a built-in break-away support underneath the cross-beam. Pro tip: In PrusaSlicer, break the base into 2 objects and then print the support object with only 1 wall, and 0 top & bottom layers. This will help it break away more easily.

Assembly
The slider piece has a little locking nub on the end of a flexible arm. You first need to gently break this arm free so that the nub can flex in and out. Then slide the slider over the end of the lever so that the nub presses into the slot in the side of the lever. Work the slider back & forth until it is smooth.

Next, insert the leaver through the slot in the side of the base and onto the hole in the TPU part, as shown in the next to last photo. The tricky part now is to flex the membrane in so that you can hook the end of the leaver over the cross-beam, as shown in the last photo. Finally, press the rim of the membrane over the edge of the base.