Introduction: Stud Mounted Sign With 3D Printed Letters
This sign has a Lot going on. CNC Plasma Cutting, 3D Printing, and a few tricks I've come up with over the years. Join me for the details of the build here after you check out the video:
Step 1: CNC Plasma Cutting
Like many of my projects, this one starts at the CNC Plasma Cutting Table.
Plasma cutting is similar to a laser except that instead of focused light, the cutting force comes from plasma, which is just pressurized air that has had the electrons stripped from the protons in order to create the 4th form of matter: Plasma. It's also about twice the temperature of the surface of the sun.
The table moves the torch around cutting out the shapes of the logo. The remaining piece is also cut out into order to create a stencil to be used in lining parts up in later steps.
Step 2: Rough Finishing
We quickly layout the parts to make sure we have everything and then grind the backs of each piece. The majority of the grinding/finishing will happen in later steps.
Step 3: Building the Frame
The frame for this sign is made from 3/4" x 3/4" angle iron that is 1/8" thick. Instead of cutting miters, we cut notches into the ends of the shorter pieces so they slide together. This choice is totally immaterial as the entire joint will be welded then ground.
Notches are easier due to the fact that in order to transition the Cold Cutting Saw seen in the first image from cutting 90 degree to 45 degree takes about a minute. Cutting notches takes about 10 seconds at my portaband, which is a hand held bandsaw. I have mounted mine to a wall in order to make it more stable.
Step 4: Expanded Steel Background
We wanted to create an industrial looking sign, so the background was made from expanded steel.
Expanded steel is a really cool product and the manufacturing is just as interesting, check out this 30 second clip to see how it is cut and shaped in one process:
The style we used is flattened, which just means it is forced through rollers after that cutting operation in order to get a smooth finish.
Lastly my wife welded the expanded steel into the frame with small tacks every few inches.
Step 5: Attaching the Studs
Wow, this is my favorite part. I recently added a stud welder to my arsenal, which is a machine made to do one thing: attach studs (smooth or threaded rods) to sheet metal.
If you want to see how I USED to add studs to signs, check out this video:
Anyway, in order to locate the studs where I wanted them to be so they'd pass through an opening in the expanded steel, I marked the position of the logo on the expanded steel, then marked the bottom of the logo pieces from underneath the sign with a sharpie.
Each piece was then flipped over and the studs were attached with the stud welder's gun. You insert a stud into the gun, set the stick out of the stud so it protrudes about 3/32" of an inch from the gun, then press down where you want the stud, and hit the trigger. In about 1/10 of a second the stud welder discharges it's huge capacitors through the stud and makes the welded joint. The finished stud isn't even hot afterward. It's super cool.
Step 6: Welding the Studs Again
With the logo piece properly studded up, it is inserted back into the expanded steel. I spent a minute trying to figure out how to keep everything aligned and settled on tape. After flipping the sign over, the studs were welded to the expanded steel, thereby attaching it all together.
Now it's time to grind the visible faces, which is pretty simple and quick with size of sign.
Step 7: My Painting Trick
I wanted to paint the frame and the logo, but leave the expanded steel raw.
Here's my trick, tape of any borders that are important, in this case, where the expanded steel meets the frame.
Then, cover the rest of the expanded steel with sand. Sand is cheap, pours easily, and will stay in place. If you have tighter tolerances, you can dampen the sand to keep it from blowing around.
After brushing off the logo face, we're ready for paint.
Step 8: Prime and Texture
The logo and frame was primed with a Rustoleum 15 Minute Primer. This primer dries quickly (more like 20 minutes), fills well, and can be sanded. After two coats of primer with a sanding between coats, I moved to a Hammered textured paint. It's important to only paint from one direction with hammered paints. If you change angles, the paint will pool and that mistake will show through.
Step 9: Painting
After Primer and Texture, the sign was painted a semi Gloss Black. Between EVERY coat of paint I lightly sanded to sign.
The order was
Sand Micro Texture
Black x 2
Sand Micro Texture? Yep, that's where you VERY lightly blow sand over wet paint. By blowing lightly only the smallest/lightest sand particles are made airborne, leading to a nice, even texture. Finish with two more coats of paint.
The whole process took 4 days, and in the end the sand and tape was removed and the frame cleaned with a blow gun then the expanded steel was clear coated.
Step 10: Bottom Detail
The bottom "by Black Stallion" detail was also plasma cut and painted, 4 coats in total in black and yellow.
The yellow rectangular plate was stuck to the expanded steel background with VHB tape, which is a foam tape with a HUGE hold. It takes about a day to get to full strength but also has a really good initial hold.
Next the black border was attached the same way. You can buy VHB tape in many widths, which is VERY helpful.
Lastly, each of the letters were super glued down to the background with a thick CA Glue. These letters were a little too detailed for Plasma cutting so I 3D Printed them in a PETG Plastic. I lost the footage of this part, so check out This Instructable for a good overview.
Step 11: 3D Printed Channel Letters
Again, some footage was lost, but the process of 3D Printing these Channel Letters was similar to This Video except that I made all my surfaces much heavier/thicker. My total print time was about 3 hours per letter.
After the letters were done we sanded, and sanded, and sanded, quite a lot in order to get a nice final finish. Lastly was some texture just like before, and 4 coats of semi-gloss black paint.
Step 12: Attaching Letters Part 1
We lined up the 3D Printed letters where they needed to go then laid down some tape to draw reference lines on. We made a mark where each stud should go and measured how far above the edge of the tape it should be then removed the letter and fired off the stud welder. We had to be sure to hit a more substantial part of the expanded steel in order to get a good bond from the welded studs.
Step 13: Attaching Letters Part 2
I had intended to glue the letters to the studs, but decided I wanted a bit more glue surface so I printed some flared cups on my 3D Printer so I could get more glue bonding area on both the cup-letter bond and the cup-stud bond. These took about 10 minutes to print 10 of them.
Next I placed the cups on the studs without any glue and glued the Channel letters to the cups. The addition of a heavy object like the wrench I used, helps make sure things don't shift around.
Step 14: LED Lighting
I didn't have any Red LED strips so I used an RGB strip and only connected the Red channel to my 12V power supply. This effectively made a red LED strip.
Each piece was soldered to wires by first adding some solder to the wire and to the contact pad on the LED Strip. This is called pre-tinning and allows you to quickly attach the two together with a light touch of the soldering iron.
Each LED strip segment was also super-glued into place in order to ensure a good bond.
Step 15: Attaching Letters Part 3
With the Channel Letters now complete, including lighting, some Heavy Gel Style Super glue was added to the inside of the cups and then quickly the wiring was run through the expanded steel where desired and the letter was placed on the stud with the aid of the Cup. Again, the wrench was added to hold things in place which the glue cured.
Step 16: Wiring
The sign had 4 lit sections, the 3 Channel Letters and the Eye cavity. The 20ga wires are small enough that all 4 can be twisted together and soldered directly to a female 2.1mm barrel jack. Again, pretinning was used to make the connection easier and stronger. Lastly some heat shrink was used to protect and insulate the connections.
Step 17: Ta Da!
I am really happy with the finished product. It's always fun to combine skills and try new things, and this project checked a lot of boxes. If you'd like to see everything from the build, check out the whole project on youtube: