CNC Backlit LED Sign

See the whole build here:

Step 1: Design the Sign and Backer

I designed my sign in Fusion 360. I started by importing vector art for the sign as a DXF in Fusion360. This will create a new sketch that you can use to build a 3D part. I scaled the drawing up so that it was approximately 28" x 17.5". You can select the coordinate space origin as the scaling point.

Next, I extruded the outline of the shape to 0.75". It's always best to extrude down so that your other operations (such as insetting the letters) can start at the top of the model.

To finish the sign, I inset the letters and outline by creating another extrude operation and insetting a negative.25". Make sure to set the operation to "cut".

For the backer, I made a sketch with a simple square and two ovals for the screw mounting points. I created another circle and a smaller oval to slot the screw in place to prevent the sign from falling off the wall.

I used the same extrude / cut operations to create this part. This time, I extruded up so that I could make the small 0.125" slot.

Step 2: Toolpaths

Toolpaths tell the CNC how to cut the part out of raw stock. First, I created a setup and configured my machine and the stock. I used the fixed size feature to set the stock to 30" x 18" and 0.75" thick (we'll build this in another step). I set my index point to the bottom right top corner with the Z axis pointing up, the Y axis pointing toward the top of top edge of the model and the X axis pointing to the right edge. Make sure to select your part as the model.

I created a facing operation as the first step to make sure the thickness of the sign was correct. I used 0" offset and I will set a Z offset later when CNC-ing the part. I added a small path extension to make sure I cover the stock. For this operation, I used a 1.25" surfacing bit.

Next, I duplicated the setup and removed the facing operation. I created a new 2D pocket operation and selected the inside of the large letters. I used a 0.25" upcut bit and configured the toolpath to run in two 0.125" depths. I then created a second pocket for the small letters with a 0.125" upcut bit and two passes at 0.0625".

Finally, I added a 2D contour operation to cutout the shape of the sign. I added tabs and used the 0.25" upcut bit at depths of 0.0625". I used two finishing passes to make sure we got a clean edge.

For the backing piece, I used a similar 2D contour for the outline with the 0.25" upcut bit. A 2D pocket on the inside of the screw holes, and a 2D contour on the screw slot with a 0.125" upcut bit.

Step 3: Making the Stock

For this project, I used some nice 4/4 x 9" curly maple that I got from a friend. I used my sliding miter saw to cut 2x30" pieces for the sign and 1x14" piece for the backer.

I used my benchtop jointer to joint the edges that would be glued together for the sign.

Then I glued the two 30" pieces together using some pipe clamps.

Step 4: CNC Machining

Next, I brought the stock to my CNC. I clamped the board to the CNC using some pressure clamps. You want to make sure that the clamps are lower than the top of the wood for the surfacing operation.

I started by setting the index of my my machine to the bottom right top corner of the part. I move the bit until it is centered over the corner and set the X and Y axis. Then I move it until it overhangs the part and set the Z axis so that it is about a piece of paper's thickness higher than the part. I'll move the bit off the part and change the Z-index to 0.02" lower so that the surfacing operation trims some material off the top.

I'll run this operation until the material is flat and then flip the part and do it again until we reach the final thickness of 0.75".

Next, I'll set the index again to the same corner and start the second setup which has the 2D contour and pocket operations. I'll swap bits in between operations. I have a Z-index offset sensor on my Shapeoko 5 Pro, so I don't need to manually reset the Z-index each time.

I'll repeat the same process with the backer.

Step 5: Oil and LEDs

Next, I filled in the letters with some black acrylic paint and sanded the top with 120, then 220 grit sandpaper.

When the paint was dry, I used some Osmo PolyX oil to make the curly maple pop and add a layer of protection to the sign. I did the same with the backer.

When both were dry, I centered the backer on the back of the sign and screwed it in. You can also use wood glue, but make sure to do that before oiling the parts.

Finally, I added my LED strip to the back of the sign with the adhesive that came with the LEDs. I cut it to length and turned it on.

That's it! Now you have a super cool LED sign to display in your shop or office. I hope you enjoyed and let me know if you have any questions!