When cutting sheet goods (like plywood and MDF) down to manageable pieces for projects, nothing beats a shop-built straightedge guide and circular saw. The guide I built is easy to make and use. The great part is it’s a dual-purpose guide. It can also be used with a router to cut dadoes and grooves, for example.
The guide starts with an extra-wide hardboard base. The base will be trimmed to final width by your circular saw on one edge and your router on the opposite edge. But first, attach a hardwood guide strip centered on the base to serve as the straightedge for clean, straight cuts.
Before using the guide, you’ll need to trim the edges with your saw and router. This will leave reference edges you can align with your cut marks on the workpiece. Just remember to use the same bit and blade so the edge remains accurate.
Finally, add the cleat to hang the guide on the workpiece and make square cuts.
You can find step-by-step plans to build a the Low-Profile seen below from WoodsmithPlans.com.
