Ambient Temperature for 3D Printing

[bobstro]

Why use a time-tested mechanical solution when you can use an over-engineered IoT device? If you're not controlling via at least one microcontroller and MQTT, you're doing it wrong. I wouldn't consider the design complete without an OctoPrint plugin with full touch GUI interface. Then you need the robotic arm to flip the light switch...

[Ender5r]

Don't forget the thorium micro-reactor to power the robotic arm 😁

[marcdraco]

Why use a time-tested mechanical solution when you can use an over-engineered IoT device? If you're not controlling via at least one microcontroller and MQTT, you're doing it wrong. I wouldn't consider the design complete without an OctoPrint plugin with full touch GUI interface. Then you need the robotic arm to flip the light switch...

HAHA! I like it

Well, as I've said before, there are *potential* drawbacks to the wax and piston approach, if we remove cost which is fairly negligible even if already have the bits.

The wax and piston mechanism converts heat into kinetic energy - pretty basic physics. But the response time is something and gradient of the hysteresis that rather intrigues me. Obviously (I hope this is obvious!) it's not necessary for the unit to open full in order for some heat to escape but there is a question of how hot it could get in the cabinet while the metals and waxes get sufficiently warm or the window to open and begin to vent air.

That would rather defeat the object of having a ventilated cabinet if the temperature rose too high OR conversely, too much heat was lost as the wax and piston closed back down.

I'm not eschewing this idea, I still think it's beautiful suggestion, but I question if the small amount of heat that's generated (in real terms) can be matched to an existing greenhouse opening solution. Greenhouses get very hot, very quickly - just like cars. Which is why you should never leave your mother-in-law in one on a hot day. I'll never live that one down as long as I live.

The IR energy from the sun even beating on a small car, I mean greenhouse, is not insignificant even on an overcast day. Give or take, it's about 1,000 watts per square meter.

Anyone want to punt some figures for a typical printer? (Asking because I don't know). I'm feeling pretty crummy right now but right off the top of my head on the back of my last clean tissue, the E3 bed heater is about 0.4 square meters at about 50w and the hot end would add about what 20-30? A bigger machine would produce more of course, but anyone who can afford to run a 1 kw 3D printer isn't going to worry about a putting a box around it to save a few bucks.

The sun isn't just coming in through a single 1 M^2 window, it's beating down over the whole structure - so you can see why things get so hot, so fast. This means there's plenty of latent heat for the wax and piston to get nice 'n' 'ot and open with some haste.

This is just a wild estimate based on some figures I pulled out of my Thorium-powered Flux capacitor (see, I am paying attention and that made me LOL) but you can perhaps see why I'm suspicious as to the efficacy of such a solution.

However, I'm the first to admit when I'm wrong and I prefer simple solutions because if you saw my last patent application it was written in such a way that I couldn't understand it and I designed the damn thing!

==== And now for some completely unnecessary levity ====

Why does it take a big man to admit that he's wrong? Because who's honestly going to go up to him afterwards, poke him in the chest and declare, "See! We told you so!"

[MambaRoja]

We'd been discussing mercury actually (with me having a giggle about how it used to be used as a cure for VD). I used Cr6 as an example of bad science, not as something to derail the thread because it was raised as part of the discussion.\

.....quote edited to save space

Back with 3D printing, much the same applies there too. People are scared that their hot ends will autoignite PLA and burn the house down and yet seem oblivious that poor quality power supplies and badly routed wiring are the real culprits. Because it's easier to blame what you can see and touch rather than the thing you can't. Bad or worn wiring, the most frequent cause of these fires is hard to see.

I will try to stay on topic but I feel compelled to provide links for science and skeptical thinking:

https://centerforinquiry.org/

https://www.skeptic.com/

https://www.cochrane.org/

https://www.brainpickings.org/2014/0...it-carl-sagan/

https://theness.com/

https://sciencebasedmedicine.org/

Do activated carbon filters increase the safety of resin and other materials printers? Which resins are the safest?

[marcdraco]

This is STILL off topic, which is detailed in the thread title and widely discussed over a number of posts. I'll keep the first part on topic and include a little more science for those interested before I indulge you again.

We're discussing the merits of active and passive methods for controlling a micro-environmental temperature inside an printer enclosure. I'll remind you that one author mentioned that although the E3DV6 head is designed to operate at ambient temperatures up to 40C, there are parts of the world where ambient (room) temperatures can exceed that.

I'm personally of the opinion that while the wax-and-piston method is an aesthetically pleasing and reliable method where there is a large heat mass (the sun beating down 1 Kw per M²) on a greenhouse, there doesn't appear to be sufficient energy in a typical 3D printer producing perhaps at best 150 W across around 0.5 M².

One of the reason why thermistors (and similar devices) are small and/or enclosed in a highly conductive material is to ensure they are rapidly responsive to even minute changes in the temperature of the material they're measuring. An easy way to understand this is to boil a kettle full of water and time how long it takes, then put just enough water in to cover the heating element and run the same timing. The energy entering the system (mostly from the heating element) doesn't change, only the mass of material that's being heated.

The thermal mass of a thermistor is negligible compared to a wax-and-piston mover such as might be used to open the window on a greenhouse and it's this factor that directly affects their ability to operate in different applications. All that said, I could be wrong. The only way to be 100% sure would be to design an experiment to put that to the test.

I've already re-designed something I created last year to included this and I'll probably publish a complete guide later this week (on Instructibles or Hackaday).

It won't cool an E3DV6 head down below the ambient temperature of the forced air though - that's a case of needing a better head.

As promised, I'll now deal with your "query" which frankly comes across as rather impertinent.

Do activated carbon filters increase the safety of resin and other materials printers? Which resins are the safest?

If you want to know about activate charcoal filters or fume hoods, then you really should start a thread about that. I would be interested to see what others have to say. I should point out though that you have to first describe what the problem is. Resin printers are unrelated to FDM printers in their entire mode of operation and there are other systems e.g. SLS, SLM and EBM (not usually for domestic use) that use completely different materials to achieve the same result: a 3D part.

I've already gone to some lengths to explain my thoughts and what's scientifically accepted on this and I'm not about to bore everyone else by repeating that ad nauseum. I'm a little confused as to why you feel it necessary to provide links to a bunch of links on science and skeptical thinking though. Have you not heard the old adage about "teaching granny how such suck eggs?"

Apropos to your claims in Post #37 where you linked not just "LiveScience" but also "Cleanwateraction" in relation to something you know very little about. Here's a professional chemist with over 20 years in the field at one of those sites on both of these elements.

https://sciencebasedmedicine.org/chr...g-combination/

Perhaps you'd like to go over there and tell Mr Pearcey that he's taken the wrong colored pill too?

[MambaRoja]

Thank you for for using the links I shared, there is hope for critical thinking!

DrVax already has posted he does not like resin printers, I was hoping others had insights of the printing environment risks they wanted to share.

[marcdraco]

Thank you for for using the links I shared, there is hope for critical thinking!

DrVax already has posted he does not like resin printers, I was hoping others had insights of the printing environment risks they wanted to share.

I was hoping you'd admit you'd been wrong about hexavalent chromium this whole time after admirably demonstrating you have absolutely no clue what you were talking about when you walked in this thread and stomped around like a pigeon in hob-nailed boots, clucking a famous quote from The Matrix.

If you want to be a skeptic young man (I'll have to assume a gender here for the sake of simplicity) you need to own up when you're wrong. And you were. Dead wrong. You relied on plagiarizing a chunk of text from Wikipedia and other badly-sourced material and then compounded that by lecturing us about science. Erin Brockovich is no environmental heronine - she struck gold simply because of a broken legal system and managed to exploit that in much the same way as the current litany of cases are being presented against Monstanto/Bayer in relation glyphosate.

One of the main skills of critical thinking is being able to evaluate evidence and, when that evidence shows your belief is wrong, you accept that and it's usual to apologize, not to try and claim a victory that was never yours.

You owe this community that.

[MambaRoja]

OK, you win, it will make you feel better.

I don't think I defended Ms. Brokovich, ever, I perpetrated "copypasta"...

[marcdraco]

This isn't about "winning" or "losing" it's about humility and even now you've not demonstrated one iota of that; and I don't appreciate your tone. My patience is wearing very thin.

You want to see what happens when I make a mistake (even a minor one)? Go back to page 2, post #28 regarding liquid mercury. I'd forgotten that while in liquid form, mercury is harmless and Ender5s corrected that:

The gaseous form or mercury is what used to cause millinery workers to go insane. To make beaver pelt hats, the mercury had to be heated quite hot, causing a lot of it to vaporize (liquid mercury will evaporate to some extent at room temperature). The milliners would breath in the fumes, which went straight to their brains. Thus, the term "mad as a hatter

You don't see either of us putting up a pet lip and sulking. I accepted I was wrong and we moved on. I find it's disarming to make light of a (non-critical) mistake because it demonstrates good will. You'll see scientists get into heated debates and often raise voices or swear at each other, but once a consensus is established, we get behind that.

If you bothered to read my posts, you'll note that I'm happy to admit where things are not my specialty and I'm perhaps speculating based on what I know. As a good rule of thumb, if a big flashy website makes a claim, particularly if it's strident doom-gloom and Armageddon-like, you can probably take it with a pinch of NaCl. Natural News is one such odious collection, as are Mercola, Infowars, Prisonplanet, 911truth and even the Huffington Post and the Intercept! Real science websites are rarely flash and they are often text-heavy with numerous detailed citations and long discussions. I'm limiting mine here simply because I don't want to belabor our host with complaints about me dominating a thread with stuff which is only tangentially related to 3D printing.

As for Ms. Brockovich...

Chromium-6 in Tap Water: Why the 'Erin Brockovich' Chemical Is Dangerous"

You are free to choose the red or the blue pill and believe what you choose to believe, opinions are not facts...

The emphasis is yours, although that could have come from lazy "copypasting". Not to mention citing other dubious and basically badly informed sources before lecturing the rest of us about skepticism. You're right that opinions are not facts, but right from the get-go, I was quite clear about the science surrounding this and my understanding of the science of PTFE pyrolisis. It was abundantly clear to me that you'd already taken up a position on Cr6 and selected the search results that supported your own preconceived ideas.

I was similarly unaware of the toxicology of Cr6 when the movie came out and I had to go look it up and talk to chemists before opening my mouth about it. It's clear that there are still a lot of sites that maintain the idiotic suggestion that Brockovich was something other than in the right place at the right time and was lionized by a movie. If I was making a film about Brockovich (or similarly dishonest people) you can be damn sure that wouldn't hold back on showing her for what she is. But selling a story like that in Hollywood is impossible - the same for Hedy Lamarr who, it's widely and fallacious claimed invented FHSS.

People prefer convenient fantasies to hard truth, it's human nature.

In a separate post, you said:

I would like to believe that the participants in the forum are of above average intellect, citizens of Lake Wobegon?

I'm struggling to understand how else that could be interpreted other than as a poke at myself or the others already in this discussion and the wider forum. That's passive aggressive and it's not smart to get in to a, shall we just say, competition with people who have already demonstrated a strong background in the topic.

[roon4660]

"I would like to believe that the participants in the forum are of above average intellect, citizens of Lake Wobegon?" I don't think our expectations pf you are that high.