Didn't have a circular saw for this one either, so I set up a guide fence to use with the jig saw and got reasonable results. Also made use of the square edges of the board purchased (I had about a 1 inch by 3 inch piece left over from a 16 inch by 72 inch board). I managed to get the support length and position accurate enough that the motion of the tabletop is smooth. As an experiment, it worked pretty well, and fit the space i had for it. Were I to build a larger coffee table with this device, I would make it wider so that more extension of the top could be gotten from it. I'd also like to use welded metal struts to make it sturdier and more compact.
(finished around winter 2004)