Wax motor
121 points by mhb 2 days ago | 23 comments
palmotea 58 minutes ago
If you want to see one in action, I found this: https://www.youtube.com/watch?v=sApyrDEXGAI
replycbdumas 2 hours ago
I'm surprised this page doesn't mention the automotive thermostat which uses the same principle to control the flow of coolant between the engine block and radiator in an ICE vehicle.
replyjammaloo 2 hours ago
Perhaps you would consider adding that information? That's would be an interesting addition!
replyWJW 2 hours ago
Using this as a greenhouse vent actuator is pretty cool. It just makes so much sense.
replybonkabonka 2 hours ago
Big Clive took one to bits some years back: https://www.youtube.com/watch?v=uPuvhnIoz2g
replyLeoPanthera 59 minutes ago
What a treasure Big Clive is. Educational, entertaining, and zero of those YouTube cliches and clickbait that everyone hates. I don't think he's ever said "Like and subscribe" literally ever.
replykazinator 44 minutes ago
The expansion of paraffin wax is substantial. I have experience wax potting guitar pickups as well as bicycle chains. I use a skinny, tall tin can for this, placed in boiling water. When the liquid wax solidifies, it not only pulls away from the sides of the can so that the resulting ingot slides out freely, but a void forms in the center. The top surface has a depression and a deep hole in the center.
replypost_break 39 minutes ago
My mini truck uses a couple of these with vacuum lines to control the choke and EGR. They are expensive to replace for obvious reasons.
replycurtisblaine 10 minutes ago
I have this in the greenhouse that came with my house. Seeing its roof closed in fall after it had been open all summer made me question my sanity.
replymoron4hire 2 hours ago
Objects like this make me think of grimdark (steam|diesel)punk works like the video games Dishonored or BioShock. It feels like there's a touch of occultism or corruption whenever one creates a device that exploits analog side effects to create machines in a closed, black-box package.
replywvbdmp 2 hours ago
I see what you mean, but it’s less the exploitation itself than its immediacy and legibility. It doesn’t vanish behind a million abstractions or complicated miniaturization processes but can be readily experienced and understood, like steam.
replyOn the other hand one might as well associate it with “solar punk”, especially when powered by ambient temperature.
bee_rider 24 minutes ago
Yes, it seems generally *punk. It’s funny that steam, diesel, and solar punk have this association with immediacy.
replyDoes the originator, cyberpunk? Lots of cyberpunk stories present us with a society that is dominated by a digital abstraction. But the protagonist is special, so, they might not be.
quickthrowman 2 hours ago
> Objects like this make me think of grimdark (steam|diesel)punk works like the video games Dishonored or BioShock. It feels like there's a touch of occultism or corruption whenever one creates a device that exploits analog side effects to create machines in a closed, black-box package.
replyThe second sentence also fits for field effect transistors and solid state electronics in general.
In the spirit of grimdark steampunk, have you ever heard of pneumatic logic? I still see these systems operating normally in some older mechanical rooms, it’s cool to see them still working after 40-50 years.
IshKebab 2 hours ago
I once had an interview at PA consulting where they asked one of those questions where they have "the answer" but their question isn't well specified enough to lead to that unique answer. They kept adding conditions, but I hadn't ever heard of wax actuators before. (I was like 19 or something - didn't get that job!)
reply
These are two separate things: thermostat will close and open based on surrounding temp., the actuator on the other hand opens and closes based on energizing a heating element that is driven by a separate thermostat.
Wax motors are pretty cool things. They rarely fail and do their job even in damp environments. I take care of my better half's hotel with approx 100 of these installed and we replace one of these once every couple of years.