A panel saw is a useful tool when you need to cut large sheets of plywood or Sheetrock, however they can be several hundred dollars if you try to buy one from your local tool store. Luckily, you will learn today, how to make your own homemade panel saw.
To make this panel saw you will need a large sheet of plywood (2' x 4' should do the trick), two rails (closet rails will do), two sets of rollers for the rails, three 4 foot 2x4s, Five 4 foot 1x4s, a small sheet of plywood (1 square foot will work), a circular saw, a hinge, and several screws.
Start by laying the large sheet of plywood out. This will be the background for your panel saw. Fasten two 1x4s to the back of the large piece of plywood laterally with one 4 inches from the bottom and one 4 inches from the top. Now cut 45 degree angles on the ends of two of the 2x4s and and fasten them on either side of the large piece of plywood and to the top 1x4, the 45 degree cuts facing inward. Now fasten one of the 1x4s laterally 4 inches from the bottom on the front side to the large plywood on its side and to the two 2x4s. You will need to cut two notches long enough for the rails to fit in 12 inches apart. Fasten the other two vertically 6 inches on either side of the vertical middle of the piece of plywood, making sure that one end of both rest on the below 1x4. These will be used as foundations for the rails. Last, attach a hinge to the top 1x4 on the back horizontally and secure the last 2x4. This will act as a fold out leg making the panel a tripod construction.
Line the rails up with the two vertical 1x4s and and fasten at all four ends of the 1x4s. Use a level to make sure that the rails are perfectly parallel, as this is key to the saw's function. Next take the small piece of plywood and attach both sets of rollers on either side of the plywood, one on the left and one on the right. These rollers will go into the rails. Take your circular saw and cut out a hole in the small plywood, large enough so that the saw part sticks through and so that the saw is facing as if it will be moving toward the ceiling. Now fasten the four corners of the saw to the piece of plywood with the screws. You can now install the rollers into the track one side at a time.
Check the movement of the saw. If it moves freely, you are in business, if it doesn't you will probably need to adjust the angle of the rails to allow for free movement. take a spare piece of plywood and lay it against the bottom 1x4, it should fit under the rails and rest on the bottom 1x4, allowing the saw to cut it in half, without cutting through the back of the large sheet of plywood. The saw height may need to be adjusted to accommodate for this.