Try This: Laser Cut and Engrave an LED-Lit Acrylic and Plywood Sign

This project overview walks through the process of constructing an LED-lit sign, from how to cut and engrave the acrylic to laser cutting a sheet of plywood.

Materials Needed

• 1/4″ (6.35mm) Plywood – 24″ X 48″ (609.6 mm X 1219.2mm) sheet
• 1/4″ (6.35mm) Acrylic – 12″ X 24″ (304.8mm X 609.6mm) sheet
• Foil tape
• Machine screws & nuts
• Wood glue
• Spray paint
• Cuttable LED light strip with adhesive
• USB extension cord (optional)
• USB wall adapter (optional)
• Laser System

For this project, Epilog used a Fusion Pro 48 120w.

Plywood

• Vector – Speed: 25% // Power: 100% // Frequency: 10%

Acrylic

• Vector – Speed: 10% // Power: 100% // Frequency: 100%
• Engraving – Speed: 100% // Power: 50% // Resolution: 500 DPI

Step No. 1: Prepare acrylic

Spray paint the backside of a 12″ X 24″ acrylic sheet. Use any color paint for this (black gives it a sharp contrast. If your acrylic is pre-masked, be sure to unmask one side before painting.

Step No. 2: Cut plywood

While the paint is drying, cut out the wooden components of the sign. Load the plywood sheet into the machine. If you’re using a smaller device, just be sure to use a sheet of wood that fits and possibly cut out the components in multiple batches.

You can use any wood or other laser-safe material you’d like. It will just affect the weight of your finished sign and the settings you need to use when cutting with the laser. Always refer to your laser manual’s list of recommended materials settings to figure out where to start with speed and power.

In actuality, this 1/4″ plywood is close to 0.2 inches in thickness, which was accounted for in the finger joints of the design file. If you’re working with thicker material, adjust the artwork accordingly.

All of these pieces fit nicely into about two-thirds of the plywood sheet, so we applied the settings of 25% speed, 100% power, and 10 frequency, and send it to the laser to cut them out.

Step No. 3: Paint plywood components

Once you have your plywood pieces, take the parts that will be exposed to the outside of the sign and spray paint them black. This includes the front frame, the side faces, and the back panel. Painting them black will help the rest of the sign blend together, leaving the focus on the sign’s graphics. Once again, you can paint, stain, or otherwise finish the components however you like.

Step No. 4: Engrave acrylic

While the painted pieces dry, engrave the painted acrylic with your chosen graphic. We used a 12″ x 24″ sheet and cut out a rectangle slightly smaller than that. We also made sure the acrylic has rounded corners. These corners will be covered by the front frame of the sign and ensure no issues come up from the fit being too snug.

Engrave on the backside of the acrylic. You want to mirror the graphic to make sure it reads correctly when viewed from the front. Print the graphic to the laser and let the machine go to work.

Adjust your settings appropriately. For this, we used 100% speed, 50% power, and a resolution of 500 DPI for the engraving, and 10% speed, 100% power, and 100% frequency for the cutting.

Step No. 5: Assemble sign

Start with creating the inner frame by gluing together the corners, using some 1-2-3 blocks to help make sure we’re achieving right angles. Also, glue in the corner faces (it provides a surface for mounting).

Then attach the side faces of the outer frame. Be sure to flip the inner frame over so the flat corner faces are on the ground. This ensures a lip is created on the inside of the outer frame. This lip is where you’ll insert the acrylic front.

Once that’s done, apply foil tape to the inner surfaces of the frame. Cover the inside of the box with reflective material. This material will allow the light from the LEDs to bounce around and evenly illuminate. Apply the tape to the frame, and then apply it to the interior side of our back panel.
Go back with a precision blade and a screwdriver to make sure the various mounting holes are not blocked.

Secure the back panel with a few nuts and bolts. Then it’s time to add the adhesive LED light strips.

Next, lay the frame on its back and lay the acrylic sheet onto the lip created by the inner frame.

Test the LEDs to make sure everything’s working correctly. Then glue on the front frame. Then, plug the sign in, and you’re set.

Hopefully, this project inspires you to think about how a laser machine can be used to engrave detailed graphics and be used in the production of parts and pieces.