gimbals?

^^^^^^^^^^^^^^^^^^^^^ Close, Bill, but no cigar. It is not necessary for the attached bar to be at exactly right angles to the level. The level is going to hang with the center of gravity of the assembly directly below the point of support. The attachment must be such that the laser beam is level while it is hanging. The easiest way to achieve this is to make the attachment adjustable (slide fore and aft.) The advantage of making the vertical bar long is that it cuts down the time that it swings or rocks before coming to rest, and reduces the effect of breezes.

good catch - I meant to say "and centered over the center of mass of the level" but forgot to say that - in fact, there is no reason for the perpendicuarity prescription except for ease of visualization - so long as the attachment point for the monofilament is precisely above the center of mass.

The longer distance reduces not only the "pendulum" effect but also any potential angular displacement caused thereby

The leveling mechanism on a surveyors tripod is functionally a plate loosely bolted down in the middle with four knurled adjusting screws around the outside, bearing on another plate below. You adjust the tilt by loosening the adjuster on one side while tightening the other, keeping both in contact by feel.

Self-levelling laser levels are actually quite reasonably priced . Check at your local lumberyard or builder's supply .

Ball joint for a camera tripod? Should be able to pick up just the swivel for $5-10 from any camera store, maybe even walmart... --Glenn Lyford