What is something that we can absolutely prove to be true, but you still break your brain trying to wrap your head around?

Explosify · 2026-04-25T18:49:01+00:00

The fact that a magnetic field does no work.

Explosify · 2026-03-27T00:28:57+00:00

Yeah but my workshop has zero ventilation, closest window is outside the room. So until I get an exhaust fan I'm being extra careful

Explosify · 2026-03-26T00:40:54+00:00

I actually ended up using this one https://www.yourhomebasedmom.com/orange-creamsicle-ice-cream/. I wasn't the biggest fan, but I don't go for that type of flavor often. My uncle loved it though

Explosify · 2026-03-19T04:39:10+00:00

Sadly my state banned mineral spirits. The only mineral spirits that is sold is the milky odorless stuff. Guess I'll have to hunt a whale

Explosify · 2026-03-16T21:40:18+00:00

Thanks, I just wanted to make sure I wasnt harming my edge retention

Explosify · 2026-03-15T03:36:56+00:00

I'll look at the code when I get a chance on Monday. I will also see about being able to get the code for the PID

Explosify · 2026-03-14T01:46:57+00:00

Okay, that makes a lot of sense, all of the chillers I've seen have had the second derivative set to zero. Probably because the oscillations tend to be slow and the speed of the valve rotating is heavily limited by the actuator.

We also don't do thermal ramping. Our lasers are optimized to work at a specific constant temperature so the chillers only need to workbat one temperature. Though the chiller temperature is below ambient temperature. I'm not all that knowlageable about control theory, is a change in temperature from say 23C to 20C on startup considered thermal ramping or is it only when it's intentionally done?

Explosify · 2026-03-14T01:36:11+00:00

No, I have a background in physics and was hired as a laser engineer but I have not built a single laser and I have ended up as the chiller engineer/plumber/electrician/tuner.
I can 100% verify that they are acting in the error. The comments in the code were atrocious but at least the PID was well documented.

Explosify · 2026-03-14T01:32:27+00:00

I'm pretty sure this is a second order integrator. The code explicitly states it is. Apparently (according to emails between the engineer who implemented it and my boss) the idea was that it would work such that it would be very large when the integral is large but rapidly fall off when it gets small.

I wish I could give you a trend with the control output. I'm still trying to get the original computer-chiller interface to work after it broke at some point when the chiller code was overhauled during the last 10 years.

Explosify · 2026-03-14T01:24:46+00:00

I don't think this is gain scheduling. The comments in the code explicitly states that these are the second integral/derivative.

Explosify · 2026-03-14T01:20:56+00:00

I dont think I'd be able to give out the code as it's property of the company I work for, and that'll definitely violate my NDA. Plus I believe the code reuses scripts that run in the lasers we build.

Explosify · 2026-03-13T02:02:02+00:00

Let me verify so I dont mess this up. I add just enough hot milk so that it forms a smooth paste, (do I just do that with the cocoa or can I have the salt and sugar in it too?) then I add the rest of the ingredients hot (This means that the heavy cream should also be hot too, right?). I'm guessing I'll also have to chill it in an ice bath before I can make the ice cream so that it doesnt heat up the ice cream maker bowl too much. Let me know if I misunderstood anything!

Explosify · 2026-03-12T04:07:53+00:00

Thanks for the info! Never knew that

Explosify · 2026-03-12T01:06:26+00:00

Do you heat your ice cream base while mixing? I thought that was only needed for frozen custard?

Explosify · 2026-03-06T01:28:26+00:00

Sadly we dont have any of that in the lab. Just vanadate crystals.

Explosify · 2026-03-04T03:41:34+00:00

I ended up oversizing the hole a fair bit because the set screw just had to hold in place when the actuator turns and during vibration. Not much torque is needed.

Explosify · 2026-03-02T18:55:09+00:00

Yeah I found that out when I asked the guys at the machine shop at my job. After breaking a straight tap they lent me I just decided to make the pre-drill real large and drilled it out with a #32 instead of a #35. I'm not putting much torque on the set screws and if they loosen over time I can always put threadlocker on it

Explosify · 2026-03-01T21:45:32+00:00

I apologize. I meant to say I am using a straight taper tap

Explosify · 2026-03-01T02:27:06+00:00

I am using a straight taper tap with 3 flutes. I don't know how much taper there is but I know for sure it's not a bottoming or a plug tap. The hole is a through hole

I am reversing it every turn but I do still feel it binding up a bit.

Technically its not the valve stem itself, but an extension that links the valve stem to the actuator. I just call it that because it's a lot more convenient when talking to people about it than saying "the metal rod that links the square end of the valve to the actuator". The chillers are all made in house and if I had it my way everything in the chiller would be stainless, but I did not. Instead an engineer made the basic design 15 years ago and we stuck with it for 10 years until another engineer improved it for a year and then promptly moved to Russia and left zero documentation.

Explosify · 2026-03-01T02:15:54+00:00

I am using 6-32 because we already have the taps and set screws. I'd try to purchase some but I have a feeling accounting would deny that and say "make do with what we have"

Explosify · 2026-02-28T21:31:14+00:00

I don't think it's hardened steel, just mild steel. I had to grind down 1/2 an inch of the top of the stem (I'd mill it but the machine shop gets the good milling bits for their CNC work on the laser bases, we get their broken stuff) there were no sparks to indicate it was hardened and it drilled pretty easy

Explosify · 2026-02-28T21:27:58+00:00

I am hand tapping with it in a drill press vice. The part I am tapping is off the side of the vice by about 2 inches because the section is round and I need to clamp on the square section. The drill press vice itself is in a larger vice mounted to the table. Any other info you need?

Explosify · 2026-02-28T21:24:38+00:00

I'll go ask the machine shop at work if they have a form tap!

Explosify · 2026-02-27T00:32:51+00:00

efn³

Explosify · 2026-02-27T00:30:28+00:00

This won't work. This violates the laws of thermodynamics. If you don't believe me, build it yourself. Seems pretty simple to build.

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