Comfort 7

Here are some extra reference images that I used for this week. Here are some characteristics for friendly forms:
A. soft edges B. not too many bulges C. suggestive "gestures" that show how to position your body D. reminds you of other friendly things

After playing around with a few geometries, I landed on a form that you can hold in your palm and hug with your fingers.

Modeling the mold and the mold's mold! I never made a mold for a mold, so it was an interesting exercise to figure out what should be subtracted from what.
I made my opening wider than examples for cases when I would be using more viscous materials for casting.

I was quite impressed by the quality of bambu printers last time I used them, so I decided to try printing the mold using 0.08mm layer height. The print quality was impressive and the layers were barely visible, so I decided to proceed without postprocessing / process the cast to remove any layer marks.

I followed the steps that we went over during the tutorial for Oomoo, but I made a grave mistake of trying to remove the bubbles in the container after mixing the two components (instead of tapping to remove the bubbles after pouring into the mold). The mixture started to harden by the time that I poured it into the mold, and I did not have enough time to tap out the bubbles. I ended up with large bubbles in the mold. I decided to proceed and just patch up any significant holes that poked through the outer surface by backing it with a cardboard. Another aspect that contributed to the large bubbles was having more amount than the amount that we used in the tutorial. It took a bit of time to make sure the greena and blue mixed evenly. Next time if I have to pour a large quantity, I will be doing it in several rounds.

Dusting the mold with corn starch helped with some toolpath smoothing

I realized the volume of the object actually uses more material and making it with plaster or metal would end up with weights that would be strenuous on wrists. I wanted to try making shells (with cavity inside) by rotating the mold while the casting material is setting, so not the entire volume would be solid. Jen suggested putting rigid surfaces around the mold and clamping for the technique. The clamps in the shop were a bit too heavy and easily loosened, so I cut out the chipboards and used zip ties to create temporary clamps.

For the first round of material tests, I tried rotating plaster in the mod. Rotating without coveing the hole + not enough material ended up with cracked shell. It seemed like the plaster pooled at the bottom and that bit survived.

with the lesson from the first attempt, the second one turned out much better. The material still pulled at the bottom, but the whole form was there. The rotating equipment would be needed to make the shell completely even around every point, but with the current hand rotating technique, I think the key is rotating enough while the material is stil drying and doing multiple coats to make sure all the areas are covered. This version still had some cracks around the hole due to lack of plaster.

With more familiarity with the rotating technique, I decided to try it with other materials. Architecture shop had bismuth alloy, so I decided to try pouring it (with the holes covered this time) and rotate it. As I was rotating, it felt like there were clumps instead of liquid. When I opened the mold after ten minutes, the mold was full of small bismuth clumps. After doing a quick test on one side of the mold to see what happens when you immediately start shaking bismuth when it is poured, I realized bismuth starts to harden as soon as it touches cooler surface, so it will start hardening and create clumps if it is in contact with cooler air. It only works well in a static environment when there is a large temperature difference between the metal and the environment.

For the second attempt, I gave the mold a quick rotation and left it to cool on one side. It worked much better, but it was still clumping. Because the mold would have used too much bismuth, I decided to give up on the metal version. It looked cool, but I wasn't sure how friendly the metal felt.

Lastly, I tried the rotation technique for soap (glycerin). I have casted with wax before, and the material felt very familiar. It seemd like out of all three, glycerin seemed to be the best for creating a shell since it dried at a quicker rate than plaster yet dried slow enough to be applied more evenly around the surface.

Here are the results of the three tess. There are still more explortaions to do for the forms + materials, but in the future, I would love to try:
1. making covers for casts (3d printed solid + silicone skin) 2. creating two parts for casing that can be opened and closed (so two molds for the two parts) 3. play with colors 4. add textures

Comfort 7: Friendly Forms