pointer to the ACS #ferrates symposium series book. #materials
#video about #bootstrapping silicone #materials from 40mℓ of sodium silicate (modulus and concentration unspecified but it looks syrupy) and 10mℓ of 95% ethanol, which he claims ethylates the silicate chains. Then he squeezes the water out of it. The resulting silicone is super bouncy, much more rigid than polydimethylsiloxane. Very impressive. By #Apoptosis.
#video of STBN TʕOORNR #writing his name in Ugaritic #cuneiform with a #tutorial on the different strokes
#video on 3-D scanning of #cuneiform tablets with a 75μm-resolution X-ray CT scanner, then #3D-printing replicas
#PDF of #PolyCast filament datasheet for #3D-printing casting molds. Doesn’t say what’s in it. 1.1g/cc, absorbs 2.09% water at 70% RH at 23° with a time constant of about a day, glass transition of 70°, decomposes at 260°, heat deflection at 52.7°–66.5°, 1745MPa±151MPa Young’s modulus, 35.7MPa tensile strength, 5.8% elongation at break, prints at 190°–220°. I wonder if you could anneal it like PLA. Supposedly it’s made of PVB, whatever that is. #materials
#PDF of #PolyCast #MSDS, from JF Polymers Suzhou. Warns you to wash your skin thoroughly with soap and water in case of skin contact but only seek medical attention if irritation persists. Also doesn’t say what’s in it.
#PolyCast product information sheet #PDF says it can be polished with isopropyl alcohol, and that you should avoid using sodium silicate in the ceramic shell, but doesn’t say what’s in it.
The 3D Prima page for #PolyCast says it’s made of “PVB” but doesn’t say what that stands for.
“The major application is laminated safety glass for automobile windshields. (...) PVB is also available as 3D printer filament that is stronger and more heat resistant than polylactic acid (PLA).” Possibly this is #PolyCast.
#Shake-the-Future #video of #3D-printing a split casting box, with alignment pins, with the pre-split casting form halves already in it, allows you to pour investment casting plaster (dental casting plaster without sand) onto the print bed, then withdraw the form from the plaster once it sets up. Sprues can be hollow, and I guess the form can too. He’s using PLA, which in this case you don’t actually want to spontaneously delaminate from the bed when it cools. And he’s running G-code on the printer (a Prusa MK4) to shake out the bubbles from the plaster! This also avoids the need for alignment pins in the form (just the box) and the need for parting dust. I bet you could do this with sand casting too! To help with withdrawing the form from the mold, he microwaves it in a plastic bag, which even permits undercuts, like lost-PLA casting. No plastic is left in the mold when you turn the furnace on. He uses his airfryer to dry the mold for two hours, then his oven for three more hours at 250°. And then he uses a microwave kiln to melt brass! He says it can even melt stainless! His alignment-pin holes were sized for M8 bolts, which also hold the mold shut. He uses a Noga deburring tool to remove the mold flash. He calls this technique “print-wave casting” because he uses the microwave. #manufacturing
#video on #manufacturing borosilicate glass #materials in a microwave. His glass ate his insulating firebrick, but he was able to get it to work by using a ceramic crucible as a firebrick liner.
Rdot Ynvisible #displays #hardware are advertised as 0.3μW/cm² plus 1mJ/cm² per update, and they claim that reflective LCDs use 6μW/cm²
"MTG Jamendo" is a dataset from 02019 of 55000 #music tracks from #Jamendo under #CC licenses, along with extensive metadata. 156GB for the low-quality audio dataset, 508GB for the high-quality audio dataset. #pasivos
#video of slinging stones at a watermelon in an 18-gauge steel helmet, 200 joules with a 28-inch sling
#video of rapper Liite reacting to his first hearing of Queen #music, specifically Bohemian Rhapsody. It’s super adorable how he loves it
another very happy reaction #video to Bohemian Rhapsody #music, this time in AAVE. This is the first time I’ve heard someone use the phrase “no homo”.
another #music reaction #video, this time to the Disturbed cover of “The Sound of Silence”, with a panel of tribal people in Sindh.