Introduction: Sculpting a T800 Coffee Cup
I wanted to make a T800 Terminator cup from the Terminator movies. You know the one with Arnold Swartzenegger, "I'll be back!" Yeah, his metal skull with the scary glowing red eyes! I made one and I just love it. Not everyone else loves it but it was fun trying to make it and it's certainly unique! I doubt you'll find anything like it for sale anywhere!
I used a 3D printer to make a "push mold", where I pushed clay into a 3d printed plastic mold to get the sculpted item very close to what I wanted, then used an additional manual sculpting method to add extra details such as actuators, and handle, lines, opened the cup area and such. I then fired, painted, glazed, and fired again and ended up with a super T800 food safe coffee cup!
So, to some degree, this Instructible is about 3D sculpting a mold and then using that 3d sculpted mold to make a 3D sculpted part. This is not really 3D printing a ceramic cup but more like 3D printing a mold that can help sculpt a ceramic part. There's a mixture of art and science to make this sculpted 3D ceramic coffee cup!
A computer with CAD software (such as Fusion360)
A 3D printer
Low fire ceramic clay
Sponge or paper towels
Kiln (or a ceramic shop nearby that can kiln fire items)
Ceramic underglaze paints
Ceramic clear glaze
Dremmel with grinding wheel
Step 1: Obtaining a Suitable Model
The first step is to find a suitable model to mold.
I found a T800 head model on Thingiverse that looked nice and downloaded the STL file.
Step 2: Modifying the Model to Make a Mold Negative
I edited the model by removing the jaw actuators, the neck actuators, and the hydraulic tubes behind at the neck. These would be very hard to mold so I removed them to make it easier to create a mold. I then added an oval at the top to make more of a cup edge for drinking. I didn't make it hollow because this will be a negative (what to cut) for a positive mold (a block to cut the negative from). I also tried to fill in any under-hangs that would make it hard to release a mold part from a clay part. I also made many of the recesses less deep so that it would make it easier to release from the mold.
Step 3: Boolean Subtract and Split
I then did a boolean subtract (In Fusion360 you would do Modify->Combine->Cut), to cut the head from a block.
Then cut the block apart to make each mold piece (In Fusion360 you would do Modify->Split Body).
After cutting, I added alignment bumps so that the mold would align and hold its shape better when assembled.
I made cut the mold into a top and bottom half and cut each half into four parts (front, right side, left side, back).
I then 3D printed the mold on my cheapo 3D filament printer in ABS (PLA or PETG and most other materials would probably work fine also). The printing took about 8 hours per part, so yeah printing took a long time!
Step 4: 3D Print the Mold
I 3D printed the mold and then assembled it.
Again, I made the mold into a top half with four parts and a bottom half with four parts (8 parts total) and I printed it with junk filament I had lying around (that's why some pieces are blue and some are read looking - the color does not matter).
I used low fire ceramic clay. I rolled the clay into one inch (2.5cm) logs and pushed it into mold making the walls of the mold. I started with the bottom half and once I built the walls up on the bottom half, I added the top half of the mold and built the walls of the top half. The walls were about 3/8 of an inch (9mm) thick. I made a top half and a bottom half and made sure they were fused together well. I made the mold in top and bottom parts like this because my fingers are not long enough to reach to the bottom of the mold otherwise.
I then let the clay sit in the mold for about 30 minutes to harden a little with a fan blowing into it for air circulation.
The difference between low fire clay and high fire clay is how high the kiln has to go to "cook" it. Low fire clay is easy to work can be fired at around cone 06 which is about 1010C (1850F) and high fire clay can be fired up to cone 1 which is about 1152C (2109F). Low fire clay is more porous, where high fire clay is more like glass (porcelain). Some glaze colors work better at high fire but there are many good low-fire color glazes so unless there is a particular high-fire glaze wanted, low-fire clay and glaze is probably the way to go.
Step 5: Demolding
After about 30 minutes, I carefully removed each of the 8 pieces of the mold from the clay while trying not to tear the clay. The clay was still quite damp and wanted to sag so I put the "jaw" pieces back on and let the clay structure dry a little more until it could hold its shape without sagging when removing the jaw pieces. Note that it's a good idea to have cardboard underneath your work area to keep from making mom mad that you're messing up her table! ;-)
Notice that at this point all of the 3d printing lines appear on the push-molded part and it's a very rough representation of the actual STL object model.
Step 6: Cleaning Up the Cup, Adding Actuators, and Handle
While the cup was still a little damp, I rolled out some clay in about 3/8" (9mm) logs and attached them as actuators and tubes at the neck. I then rolled out 1/8" (3mm) logs and attached them as jaw actuators. I also hand crafted a king of mechanical finger looking cup handle to the side of the cup.
To attach clay to clay the place where they meet needs to be wetted with water and scored and then pushed together to make a sort of "slip" fusing.
The inside of the cup, I scooped out the clay walls so that they were not so thick. I needed them to be thick for molding to hold its shape but if I left it that way, the cup would be really heavy. So I scooped the walls of the cup down to about a 1/4 inch (6mm) or so. I used my index finger and thumb to feel the wall thickness while scooping. I suppose I could have made some sort of wooden calipers but that didn't seem necessary.
I then let the cup dry for a couple of days until it was completely dry.
I then cleaned off all of the flash lines (the places where the mold pieces come together) with a cleanup tool and sanded them smooth with 100 grit sandpaper. I then used a wet paper towel to go over all of the sanded places to make them even smoother. I also sanded the inside and smoothed with a wet towel. I had to use a dowel to push the wet towel down to the bottom of the cup since my fingers were not long enough. Some people use a damp sponge instead of a wet paper towel but a wet paper towel works fine too and sometimes can get to places a sponge cannot.
After smoothing, I used the sculpting tools to add features such as lines around the eyes, and cleaned up areas, and added extra detail such as the teeth, jaws, eyes, nose, and neck, where the mold just wasn't detailed enough.
Step 7: Firing to Bisque
Notice that the cup in the kiln is a lot more refined than the part that came out of the mold and also the previous section where it was still quite rough. A lot of time doing touch up sculpting, sanding, smoothing, and various cleanup sculpting took place.
I put the cup into my tiny 110V kiln and fired it. I have a digital PID controller and I fired it at 100C (212F) increments for 30 minutes each increment up to 1010C (1850F). I then turned off the kiln and let it cool slowly and completely before removing (about 3 hours). As quick as that seems, this small kiln can fire even quicker than that but I was trying to go easy on it. Probably really I should go even slower but hey it worked. This first firing turns the gray clay "greenware" cup to hard white bisque cup.
Notice in the picture the cup is so tall that I had to lay it down to get it to fit in my tiny kiln. The lid barely fit and before firing it actually touched the cup but the cup did shrink about 10% when firing so it was OK.
So, after firing I picked up the cup and the handle broke off and the hydraulic tubs! Oops, I forgot to do the slip scoring join method when building the handle and hydraulic tubes. Bummer. Well, I tried to add some clear glaze to fuse it but that didn't work so I just figured I didn't like the look of the handle anyway and the hydraulic tube are not that noticeable missing. So anyway, that's a good reminder to do your scoring and wetting well when attaching clay to clay.
Side story: (A mini Instructable within an Instructable?)
My mom gave me the old kiln that wasn't working. I replaced the kiln wire with Kanthal wire purchased from Amazon, a PID controller purchased from AliExpress, and a Thermocouple purchased from Amazon. I used about 1/3rd of the Kanthal wire and used a 1/16th inch (1mm) Allen wrench and wound it between the wire to separate the coil from itself so that it wasn't touching itself and creating a big short. I found a Youtube video that told how to hook up the PID controller and viola, I have a working 110V kiln again (actually it took me a few tries to get it right but yay it works!). So really a kiln is just some fire bricks, a coil of Kanthal wire (use ohms law to figure out how much you need and keep it below 1500Watts), a PID controller (with Solid State Relay and heat sink - mine came with it), and a thermocouple that can do up to 1300C. There's probably an Instructable here that will show you how to make one and be careful since it uses deadly voltages.
Step 8: Painting and Glazing
I then used Duncan underglazes to paint the cup. I painted the eyes red, I painted the skull gray by mixing like 10 parts white to 1 part black, and then painted the teeth white. Even though the teeth were white I painted them white to give them a base coat. I then mixed a darker gray by using about 5 parts of white to 1 parts of black (or double the black). I then painted into all of the crevices and receding parts the darker color. I then used a damp paper towel to wash off the dark color a bit which helped to give a nice dark wash to the lines detail, the teeth detail, the neck detail, jaw detail, eye sockets, and sides of the head and such. So if you look closely, you can see the darker gray although it's not very high contrast. I then let the underglaze dry for about a half a day.
I then gave the cup three coats of clear glaze inside and out and let that dry for about a day.
I then placed the cup in the kiln on kiln stilts (that I made and fired previously from clay and kanthal wire) so that the glaze would not stick to the kiln floor. I then fired the cup a second time which turns the glaze to glass. The underglazes and the clear glaze of course are food safe after firing.
The glaze does stick a little to the wire on the kiln stilts but since the touching points are so tiny just a little tug and they come off easily. Where they touch it can be sharp so I used a rotary tool with grinding head to sort of sand off the sharp edges where the kiln stilt wires touched.
Step 9: Finished!
After firing the colors darken a bit. Notice that the red and grays are a bit darker than before. Also the cup now has a nice glass finish all over. The inside I didn't paint so it appears white since the glazed bisque is white.
I put the cup into my Keurig and yay it fits! Even without the handle the cup is not hot with coffee in it, just warm.
So, I've been drinking from my T800 cup for a few days now! Some people love it and some people hate it. I get weird reactions from that would be great for Halloween or that is really cool or that is really scary. I guess it is sort of scary but I'm still happy with it and I like it a lot!
Participated in the