How to Cut Clean Openings in Plywood and Cabinet Panels
Whether you're building an entertainment center, a cabinet, or a workshop storage project, there are times when you need to cut a large opening in a plywood panel.
These cutouts might provide clearance for electrical cords, allow air to circulate around electronic equipment, or create access to the inside of a cabinet.
The challenge is making an opening with straight, smooth edges and neatly rounded corners.
A jigsaw can remove the waste quickly, but it can be difficult to follow a layout line perfectly. And trying to cut the entire opening with a router can be unnecessarily time-consuming.
Instead, I use a simple three-step method that combines a drill, jigsaw, and router.
Step 1: Drill the Rounded Corners
Start by laying out the opening on the plywood panel.
For the cable and ventilation openings in an entertainment center I built, I wanted rounded corners rather than sharp inside corners.
To create them, I drilled a 2"-diameter hole at each corner of the opening.
The holes establish the corner radii and provide a convenient starting point for removing the waste.
Position the holes so their edges meet the straight layout lines of the opening.
Although the openings in my project varied in size, I used the same basic method for each one.
Step 2: Remove the Waste with a Jigsaw
With the corner holes drilled, the next step is to remove the material inside the opening.
A jigsaw makes quick work of this task.
The key is to cut close to the layout line without cutting into it.
Keep the blade on the waste side of the line, leaving a small amount of material for the router to remove.
There's no need to make the jigsaw cut perfectly straight. At this stage, you're simply removing most of the waste so the router can make the final cleanup pass.
Support the panel securely while cutting, and make sure the waste piece can't fall or bind the blade as the cut is completed.
Step 3: Smooth the Edges with a Router
After removing the waste, the opening will have the basic shape you want, but the edges may still be rough or slightly uneven.
That's where the router comes in.
Clamp a straight piece of hardboard along one of the layout lines to serve as a guide.
Then use a pattern bit with a guide bearing to trim the remaining waste flush with the straightedge.
Repeat the process along the remaining straight edges of the opening.
The router removes the uneven material left by the jigsaw, producing smooth, straight sides.
The drilled corner holes provide the rounded corners, giving the completed opening a clean, consistent appearance.
WOODSMITH TIP: Make a Test Cut First. Before routing the finished panel, test your setup on a piece of scrap plywood.
Check that the guide is positioned correctly for the router bit's bearing and cutting diameter. Make sure the bearing rides against the guide and that the cutter removes material only on the waste side of the layout line.
If the panel is thick, take multiple shallow passes rather than removing all the remaining waste at once. Keep the guide securely clamped and follow the proper feed direction.
Clean Openings Without Complicated Jigs
The beauty of this method is that it doesn't require a special template or complicated jig.
The drill establishes the rounded corners, the jigsaw removes the bulk of the waste, and the router produces the finished edges.
It's a practical technique for cutting openings in cabinet backs, plywood panels, entertainment centers, and other furniture projects.
And once you've used it a few times, you'll find it's an easy way to get consistent results on openings of different sizes.
Get More from Your Router
A router is one of the most versatile tools in the woodworking shop. With the right bit and a simple guide, you can make accurate cuts, smooth edges, and create openings that would be difficult to produce with other tools.
Explore more Woodsmith router tips, jigs, and techniques for improving your woodworking projects.
EXPLORE ROUTER TIPS & TECHNIQUES → Simple Router Techniques for Cleaner Cuts
