Free Circular Saw Cross Cut Jig Plan
Vinyl Siding Cutting Jig

This circular saw cross cut jig is so easy to make and so easy and accurate to use, you will be kicking yourself for not thinking of doing this sooner!  This is the jig you need to turn your circular saw into an accurate cross cut saw.  If you are cross cutting wide boards such as 1 x 12's, vinyl siding, or soffit pieces, this is the portable jig you want to have on site.

Materials:

One, 3/4" x 24" x 48" Plywood Panel used for the base.

Two, 2 x 2 x 48" used for the material guide rails.

One, 1/4" x 6" x 24" Plywood Panel used for the guide brace.

One, 1 x 2 x 24" Pine or any hardwood used for the guide fence.

24, 1 5/8" Wood Screws.

Step 1 - Select 3/4" x 24" x 48" Base Panel; Select the two,  2" x 2" x 48" rails; attach the rails to the panel with the screws; ensure the rails are straight, parallel, and equal distance along each edge.

Step 2 - Select the 1/4" x 6" x 24" Plywood; select the 1 x 2 x 24" hardwood, straight board fence; attach the fence to the plywood to form the saw guide fence assembly; ensure it is applied straight and square; use a speed square or carpenter's square to ensure accurate placement.

Step 3 - Select the Fence assembly and attach it about mid-point to the 2 x 2's of the base; use your squares to ensure the guide is perpendicular and equal distance to the 2 x 2 rails. 

Step 4 - Select your circular saw; place it on the guide, against the fence; set the depth to cut about 1/8" into the base panel.  Make a pass, a groove  through the 2 x 2 rails into the plywood base; this groove becomes the measuring point for cross cutting all future accurate, straight cuts.

Recommendation:  When cutting multiple pieces to a similar length, clamp a stopping block at a given point as shown above; make your cut and remove the measured piece; advance the material to the block and make another cut; another identical measured piece.  This procedure is ideal for cutting soffit pieces (be sure to use a metal cutting blade and/or reverse an all-purpose blade).

This crosscut jig is great for cutting vinyl siding.  Another recommendation when cutting vinyl siding, reverse your blade or use a special vinyl cutting blade.