I have an after-market "Kreg style" pocket hole jig that uses a thumbscrew to secure the board into the jig. One of the things I liked with the Kreg was the toggle clamp to hold the board. I designed this clamp to upgrade my pocket hole jig. You could use this clamp for any light-duty push-pull clamping solution.

The barrel is tapped with a 1/4" - 20 thread to fit the carriage bolt shown. The rest of the nuts and bolts are #6-32.

Here is a production version of a similar style clamp made of metal:
http://industrialcomponentsgroup.com/toggle-clamps-push-pull/push-pull-toggle-clamps

Print all the plastic parts, I used ABS plastic.

Sand mating surfaces for tight, clean fit.

Tap barrel with 1/4-20 tap.

Finish (I used acetone vapor method)

Insert barrel in clamp then glue into square base with cyanoacrylate (super glue).

Bolt remaining parts together

Insert 1/4-20 carriage bolt with adjustment nut into barrel.

Enjoy.

Comments and remixes welcome.