Channel Letter Sign Maker

A channel letter is a hollow, letter-shaped can with LEDs inside and a translucent face on top – the lit letters you see on shop fronts. This channel letter maker prints the can (back and side wall) on your 3D printer and gives you the matching acrylic face to cut on a laser, so you can build an LED letter sign DIY at any size your bed allows.

Each letter prints a real multi-perimeter wall (1.6 mm by default, 1.2–3 mm) with an inner ledge drafted at 45° so it needs no supports. The face sits flush on the ledge (or a little recessed), counters such as the hole in O, A and B keep their own walls, and the wire and mounting holes are printed in. For letters over 300 mm, use a thicker wall or a backing board.

The face is the inside opening of the letter minus the fit gap (0.3 mm a side by default). It drops inside the wall and rests on the ledge. The SVG and DXF cut paths are then grown by half your laser kerf (0.15 mm by default for a CO2 laser), so the pieces come out at the size of the face, not one kerf smaller. Measure your own kerf with the Laser Gauge Maker for a tight fit.

3 mm opal (white diffuser, often sold as "LED opal" or 30–50 % light transmission) is the sign-industry default: it hides the LED dots at 25–40 mm depth. 2 mm saves weight on small letters, 5 mm is stiffer for big ones. Coloured translucent acrylic works too. Pick the thickness in the tool and every seat and face follows it.

Use 12 V LED strip – 8 mm SMD 2835 (about 9.6 W/m) or 10 mm SMD 5050 (about 14.4 W/m) – or 12 V 3-LED injection modules for deeper letters. The inside of every stroke must be at least the LED width plus 2 mm; the tool warns you where it is narrower. It estimates strip length per letter from the inside perimeter, the total watts from the W/m you enter, and a 12 V supply with 20 % headroom.

Light-coloured PLA glows through a thin wall, so the sides of the letter leak light and the edge looks blurry. Print the wall in black or another dark colour and, for the brightest face, paint the inside white (or line it with white tape) after printing.

Choose stud holes (for M4 threaded studs or screws) or keyhole slots in the back of each letter, then download the 1:1 drill template, print it at 100 % (the tiled PDF splits it over A4 or Letter sheets with overlap marks and a 100 mm check bar) and tape it to the wall. Optional printed standoff spacers hold the letters off the wall for a halo glow and room for wires. A 5 mm wire hole in each back lets you daisy-chain the letters behind the sign. Big signs mount best on a backing board – the template includes its outline.

Joined makes every word one hollow can with one acrylic face: the letters are fused into a true union, so there is no wall between them inside and the LED strip runs through. Choose how they connect – overlapping each letter into the one before it, a spine bar along the baseline or through the middle, or natural joins. The seven script fonts (Pacifico, Lobster, Damion, Yellowtail, Kaushan, Leckerli One, Dancing Script) default to natural: each word is drawn whole with the font's own connections, letters that do not quite touch are slid together just until their strokes overlap wide enough for the LED channel, and only a gap that is still left gets a short, rounded bridge as wide as the stroke – no bars. Script capitals (OPEN) do not connect in the font, so for flowing script try Title case or lowercase. Dots of i and j, accents and punctuation are bridged into the word or kept as separate small pieces, as you choose (script fonts keep them separate by default – a bridge wide enough for the LED would swell the thin stem under the dot). With Separate letters a script word keeps its flow too: it is drawn whole and each letter is cut free where it joins the next, with a 3 mm gap, so the letters still line up like handwriting. If strokes are thinner than the LED needs, the tool warns you; Bolden grows every stroke a little.

Yes. Upload an SVG with filled paths (nonzero and evenodd fill rules, nested holes and white cut-outs are handled; strokes and text must be converted to paths first), or a PNG/JPG that is traced in your browser with a threshold, invert, smoothing and speck removal, shown over the image before you build. The logo is scaled to the letter height or a width you set, and every separate part becomes its own letter can – or, with Joined, one piece with bridges.

With a flush face, tick "Trim cap": you get a thin printed frame per letter that presses over the rim and holds the face edge, so you can lift it off to service the LEDs. Without it, glue the face to the ledge with a few dots of silicone.