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[Starver]

Also, the solvent I was thinking of earlier probably was dichloromethane,

This conversation had me thinking of 1,1,1-trichloroethane (which I think was Tippex's thinning agent).  Does anyone use Tippex[1] any more? Except for various political parties at voting time...

[1] Other brands are... or were... available.

[wierd]

whiteout by any other name...

Surprised TCE did not get mentioned. (did you know they used to use it to decaffeinate coffee way back when? Scary.)

Dont worry, they use supercritical CO2 these days. Much safer.

[bloop_bleep]

Compression is (in principle) adiabatic, so it doesn't increase the heat content, just the temperature; the higher-temperature refrigerant now loses heat to its surroundings because those surroundings are at a lower temperature and, when decompressed adiabatically again, drops to a lower temperature than it started at because it lost heat.

Yeah, I guess temperature is what I meant.

Surprised TCE did not get mentioned. (did you know they used to use it to decaffeinate coffee way back when? Scary.)

Anesthesia refrigerator. Cool your beer and cool your mind... at the same time!

[bloop_bleep]

Sorry for double post, but I have a question about 3D printer piece annealing. I have PLA filament, which produces pieces that are rather brittle. I heard PLA can be strengthened by annealing at high temperatures under the melting point, but that these temperatures could cause warping. I was wondering, does it make sense to encase the piece in clay or some other kind of mold after printing, but during annealing, to try to prevent warping? I was planning on annealing my pieces in water.

[wierd]

Maybe if you use silicone mold maker to support the part before heating it?

Personally though, if you are gonna go through the trouble of basically making a mold for the part, I would just go the next logical step, and pour the mold with resin and make a resin version of your print instead.

[bloop_bleep]

Ah. Yeah, that might make sense. I could use the 3D printed part as a mold mold, to make the mold for the actual piece.

Then the question becomes what to use as materials for the mold and the piece... You mentioned epoxy for the piece itself, which I think is good. For the mold you said silicone, but isn't that expensive? Does it make sense to make the mold from epoxy, wait for it to harden, then make the piece itself inside the mold? Would it form as two separate pieces?

There's also the question of porosity. Is epoxy too porous for high pressure liquid inside the compressor?

[wierd]

urethane rubber is cheap at least.

https://www.amazon.com/Enduro-Soft-Polyurethane-Casting-Durable/dp/B07YCV6491/ref=sr_1_6?dchild=1&keywords=2+part+silicone&qid=1603821431&sr=8-6

Then get yourself some casting resin.
Smooth-On is a namebrand, so is kinda pricey.  There are others out there.
https://www.amazon.com/Smooth-Cast-305-Urethane-Resin-Trial/dp/B00ZGOSTTY/ref=sr_1_6?dchild=1&keywords=smooth+on+resin&qid=1603821664&sr=8-6

I doubt you are going to be doing a huge item, so this should be fine.  See also this useful youtube video.
https://www.youtube.com/watch?v=1vrLXTzS9lo&feature=youtu.be

and this one as well.
https://www.youtube.com/watch?v=0P9KmCjOWFQ

[Starver]

I thought I'd necro-bump this thread, rather than the Engineering one, etc. There may be yet another thread that could do with similar love, but that can wait until next time.

Latest news about the 'earliest' scientific computer.

(...i.e. the earliest known and 'surviving' one. That's not still awaiting some Lara Jones/'Indiana' Croft type person to discover it and try to keep it from Bad People.)

[Kagus]

I thought I'd necro-bump this thread, rather than the Engineering one, etc. There may be yet another thread that could do with similar love, but that can wait until next time.

Latest news about the 'earliest' scientific computer.

(...i.e. the earliest known and 'surviving' one. That's not still awaiting some Lara Jones/'Indiana' Croft type person to discover it and try to keep it from Bad People.)

Oh snap, they think they might have worked out the Antikythera mechanism? That's badass, that thing's been sitting around for ages.

[ChairmanPoo]

I think I've been reading about people having figured it out several times over the last 15 years. IMO nobody has "figured it out" but apparently many teams have their own theory and want to push a paper

[Maximum Spin]

I think I've been reading about people having figured it out several times over the last 15 years. IMO nobody has "figured it out" but apparently many teams have their own theory and want to push a paper

It's more that they've been consistently figuring out parts of it over the last 15 years.

[ChairmanPoo]

https://chandra.si.edu/photo/2021/uranus/

Astronomers have announced the first detection of X-rays from Uranus.

Uranus, the seventh planet from the Sun, is an ice giant planet in the outer Solar System.

Like Jupiter and Saturn, Uranus and its rings appear to mainly produce X-rays by scattering solar X-rays, but some may also come from auroras.

Chandra observations from 2002 and 2017 were used to make this discovery.

I know its a bit of a fringe idea, but I wonder... could it be there's a black hole in Uranus?

[Eric Blank]

Aliens got stuck during probing, they're sending a distress signal.

[martinuzz]

https://chandra.si.edu/photo/2021/uranus/

Astronomers have announced the first detection of X-rays from Uranus.

Uranus, the seventh planet from the Sun, is an ice giant planet in the outer Solar System.

Like Jupiter and Saturn, Uranus and its rings appear to mainly produce X-rays by scattering solar X-rays, but some may also come from auroras.

Chandra observations from 2002 and 2017 were used to make this discovery.

I know its a bit of a fringe idea, but I wonder... could it be there's a black hole in Uranus?

Nah, the measurements have been distorted by methane nebulae from Deinarsch

[feelotraveller]

It's actually a wormhole.  Passing through results in permanent change.