Accurate Panel Ripping With Circular Saw

My shop is pretty small and often I need to rip a sheet of plywood or paneling. For years I have used a long straight edge and clamps to cut large sheets. One of the problems is my straight edge isn't really all that ridged, it's a two piece affair and it doesn't take much effort to flex it. Also, many times the "C" clamps were in the way. Then there was the problem of accurately figuring out where the cut would be made.

These are the materials I bought, much was made with things I had around the shop.

1. Main beam 1020 T-slotted profile 102 inches long.
2. Sliding part of the cutting guide 1050 T-slotted profile. 2 reqd, I used about 4 inches for each one.
3. Brass thread insert 2 reqd, although not absolutely necessary.
4. T slot knob kit I use these thing all around the shop.
5. Various pieces of hardwood. I use walnut because I have a lot of it.

Your main beam can be made from many things, as long as it is straight and ridged. I like the extruded aluminum, it is lightweight and incredibly strong for it's weight. This extrusion is 1 x 2 inches 102 inches long, I tried the 1 x 1 and felt it to be too flexible in 8 feet. I use the 1x1 when cutting across a full sheet of plywood. The T slots make it easy to clamp in place.

1. The first thing to be done is to set up the guides. Clamp the beam to a piece of wood and using the beam as a fence make a small test cut. I make my own T-bolt clamps out of hardwood. You can make a T-bolt by grinding a bit off of the sides of a carriage bolt head, just enough so that it slides easily in the slot.

2. Set up both cutting gauges to the side of the cut closest to the main beam, tighten wing nut on side. This only needs to be done once although, I recommend checking this setting if you change blades or use a different saw.

3. Place a guide at each end and lightly clamp them to the main beam. Clamp beam onto the piece with the gauge set to your cut line. Do not loosen the slide on the guide.

4. Remove the set up guides and make your cut keeping the saw snugly against the fence.

I only put the guide back on show that the cut is at the end of the setup guide.

These are the key to getting your cuts where you want them. Before I made them it took me forever to accurately get my beam in the right place by measuring and clamping with "C" clamps.

The dimensions depend on what you use as a main beam and your saw. Any nice hardwood should work. I made the notches with a dado blade on the table saw for the wide one and a router bit for the narrow one. If you don't have a those tools there are many ways of doing it. I made a fairly snug fit but, looking back they really don't need to be. The notches do need to be square with the piece and 90° with each other.

Make sure you have the grain length ways and have enough material above the wide slot for a bit of strength. If you have a drill press use it to make sure bolt holes are square with the piece. The end hole with the threads doesn't absolutely have to have the brass insert. I have had very good luck using a tap directly into the wood, there isn't much stress on it.

The side clamp must us a "T" bolt or it will split the side out of the groove.

Hope you enjoyed this and it will help you cut straight lines while making sawdust.