: I have been contemplating using a circular saw on my next project, I had
: thought of building a table to cut strips of plywood with a fence the same
: height as the boards I am cutting, a second adjustable fence on top of the
: first would serve as a guide for the saw. The circular saw would be set to
: cut just below the depth of the lumber, and in time the plywood table
: surface may have to be replaced. This way I would also be able to cut the
: gunwales on the same setup. I believe the table would not have to be more
: than 12 feet long as this would support 2/3 of a 18 foot peice of lumber.
: Anything has to be better than ripping on the Shopsmith I used on my first
: project.

I use a similar technique, here are the details. I use a finishing quality blade with a thin kerf to minimise waste. The saw is fitted with a ply sole which clips on the metal sole using mirror clips. I attached the ply sole to the saw then lowered the blade while running through the ply to create a zero-clearance slot, this gives very clean cuts. I use a guide about three times the length of the sole. I scribed several accurate lines on the sole at 1/8 intervals which helps me get the guide in the correct position and parallel to the blade. Finally, I use minimum cutting depth and place the wood on a table which has a sheet of insulating foam on top; this protects the table and reduces blade wear and force.

Typically, I get variation along a 12 foot cut of about 0.010 inch, which is close enough for most purposes. I usually cut a dozen or more strips before I have to plane the edge of the plank straight. I cut a point on the leading edge of the guide which improved the cut accuracy as wood dust was getting trapped under the guide. The guide must be absolutely straight too.

The hardest part is controlling the cord and vac hose: I now have overhead vac and power outlets in my workshop which helps a lot.