HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
Yep, you read the title right! This is a full overhaul of the printer's hotend and chamber, yielding very comedic nozzle temps and unheard-of-for-the-Core-One chamber temp stability (The goal here's to make it more reliable, not to get it past 55c, although that's possible with a future alternate firmware at your own risk)!
Preface: As of 7/13/2025, this project is a work in progress. To view the latest updates, check out the Github! ( https://github.com/Rc8941/Prusa-Firmware-Buddy-HT-Core-One ) This forum post is made before the finishing of the project on purpose, so people interested in making their Core One a high temp machine can find out about this project sooner than if I wait until it's done, or in other words, to gain a little traction before full release. (And for me to see how many other people also care about a high temp Core One!)
For full info on the project, I recommend the Github, but here's a short(ish) rundown!:
This mod is designed to kind of be around 3-5 mods in one, all with a common goal of making your Core One a high temp workhorse, while keeping a modular-esque style for people who don't want or need the whole package. This mod is designed for being borderline overkill while 1. keeping every change fully justifiable so long as you need it as a user, 2. keeping unnecessary costs down or gone entirely, and 3. exchanging every dollar (Or whatever your local currency is) you put into it for performance, reliability and safety. I think this is a nice spot to disclose that I am not responsible to anything that happens to your printer, its surroundings, you or anything else it affects or may affect, as while I designed it with safety in mind it's ultimately your choice and your responsibility if you mod your own printer in this exact way.
With that out of the way, here's what it actually will do for your printer!:
Hotend:
- Upgrade the thermistor to a PT1000 wired directly to the Loveboard, rated for 500c
- Upgrade the heater cartridge to a 65w, rated for 500c one
- Upgrade the nozzle solution to an adapter+V6 one, to make it able to survive at 500c (No native Nextruder nozzles to my knowledge say they're rated for anything above 300c, let alone 500c)
- Upgrade the stock aluminum heaterblock to a plated copper one to survive 500c
- The silicone sock, and all readily available Nextruder socks, to my knowledge, kinda won't survive these temps (Or anything above 300c)! So, we replace it with a few layers of cut exhaust wrap held on by steel zip ties, rated for ~760c and ~1200c respectively! Same purpose, different form, an industrial aesthetic!
Electronics:
- Upgrade the PSU to a 24v, 480w one. This is to free the stock, 24v 240w one for powering solely the heated chamber, while giving your printer extra headroom for that heater cartridge and whatever else you add to it. And due to sharing grounds between the two PSUs, power panic still works just as intended so long as you don't for whatever reason turn off the main PSU before you do the secondary one! (During a power outage they will both go out at the same time, in theory, resulting in a working power panic feature. Aren't confident in it? Connect the main PSU to a UPS and not the second one, so when power goes out the printer sees it yet keeps power for way longer than it needs to react.)
General chamber changes:
- Patches all the microgaps within the Core One's frame
- Lines most of the interior walls with a heat reflective wrap, to help promote heat staying inside the chamber instead of soaking into the steel chamber and escaping into the nearby area. Won't be perfect unless done rigorously, but a lot better than nothing!
- Upgrade the door sealing solution! For people who put the handle on slightly off resulting in no door-to-foam contact! And for general reliability boosts. Fixes the bottom lip being unsealed, too!
Heated chamber mod:
- Add a 24v 200w heating pad to the underside of the printer's bottom steel plate, with an integrated 100k NTC thermistor
- Insulate the pad with a ceramic fiber blanket to prevent heat going the wrong way, reducing heat transfer to the chamber and sending stray heat towards the extra electronics, which are mounted under the printer.
3. Add an Arduino Giga (USB Hosting) to the bottom of your printer! It will converse with the printer to retrieve chamber temp/target temp data.
4. This Giga will use a relay, the stock PSU (Separate from the printer's power!!!) and data from the pad's thermistor, to turn on or off the heating of the pad.
5. Resultantly, due to the thermistor having to be read by the Arduino, a breadboard has appeared on the printer!
6. The mounts for the beds linear rails (Bottom side), and the Z motor mounts, are edited and are going to be sent to PCBWay for SLM printing aluminum unless you have an alternative. Galvanic corrosion not included!
There's a plausible possibility of (In the future)...
XY Stepper motor coldboxes, a bunchhhh of aluminum parts, watercooling?? etc. to allow chamber temps beyond 55c, beyond 100c, PEEK??
It's a thought I've had in the back of my mind for a while now, and I'd love to act upon it some day after the main mods are finalized and perfected. I'd love to hear if anyone else feels the same!
Woah, that's a lot! Must be a pain to put together, with lacking documentation, right? Nope! Before I release the mod as final, I require myself to make fully in-depth, Prusa-Style assembly guides for every single thing this mod does, even the PEEK part if I ever get to it! And the assembly's not even that difficult! If you want to fully embrace the Prusa-style docs, buy a pack of gummy bears and eat as directed! (No, the assembly's not that long, I just added it because who wouldn't want gummy bears throughout their hard work?)
As of writing this, the estimated time of completion is August 2nd, 2025. That's my goal time to finish it, but things may come up or I may even get ahead of schedule! For the most recent time estimate, visit the Github, found at both the semi-top and main bottom of this forum post!
That's all I really have for now! I'll post extra stuff here, but mainly on the Github, as time goes on and I work through more of the process. As of writing this, I'm simply waiting on half my parts to come in, the concepts for everything are fully completed and I just have to make sure assembly works, and the mods work as intended, reliably and safely. More detail on Github! This project will be finished, as it's for more than just a passion project, I assure you! If I don't finish it, I give you full permission to eat the gummy bears all at the start instead of throughout the assembly. (I'll finish it, of course, this is just a joke!)
I'm curious as to what you all think of this so far! Any comments? Suggestions? Consider responding to the poll, too, I wanna see the interest in PEEK on the Core One! Friendly reminder that chances are it won't happen by me, this is the only thing mentioned that's not guaranteed, but if enough people want it I might as well make and release concepts for how it could work!
Yet again, check out the Github for more detail!: https://github.com/Rc8941/Prusa-Firmware-Buddy-HT-Core-One (Just remember: The firmware isn't matching my current firmware on my printer until I verify all these hotend parts work as intended. Ignore the code until then, the HT changes aren't committed yet!)
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
Personally I wouldn't print with peek, pekk or pei souly because of the insane cost for hobbiest.
However I would be interested to print with higher temps, so I could print PPS-CF, PPA-CF and other more affordable filaments.
They are around the 350°C mark and need a heated chamber, so I am still interested.
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
I’m personally trying to do direct print-to-use prints and the material I want to print requires some printing temps above 320 C so I would prefer a maximum temperature of up to 400-450 C. 500 C would be a bonus.
I can only print so many prototypes but need to test the material in autos and in extreme outdoor temperatures. If I print the material it will be made out of then that would be perfect since most printers capable of 500 C with an heated chamber are just too expensive.
I really like the break down of how to do the upgrades too. Very helpful and modular. I really like the heated chamber mod because it’s recommended on some filaments I want to try out.
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
I honestly feel the exact same way! And the existence of PPA-CF is the entire reason this mod exists, so as long as everything goes to plan then you'll likely be very happy with this mod, as everything's kinda focused around PPA-CF!
My stuff (Hotend parts only) is scheduled to arrive tomorrow, but judging off distance I think they'll be arriving sometime Wednesday or Thursday. I'll update the Github with my findings once I get everything and try it all out! And may make a mini version of the mod with only the hotend upgrades for now, so people like you don't have to wait as long to begin. If I do, which I likely will, I'll also post an update here when it's done! Thanks for sharing your interest!
Personally I wouldn't print with peek, pekk or pei souly because of the insane cost for hobbiest.
However I would be interested to print with higher temps, so I could print PPS-CF, PPA-CF and other more affordable filaments.
They are around the 350°C mark and need a heated chamber, so I am still interested.
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
One weak point (which is why Prusa doesn't suggest high chamber temperatures) is the love board. Semiconductors have maximum and minimum temperatures that they are rated for operation, and most commercial grade semiconductors have a max temperature rating of +70°C. See this Wikipedia article. Even most industrial grade semiconductors have a max temperature rating only of +85°C... You would need either military grade (or as mentioned in the Wikipedia article Maxim's Automotive grade or similar from the manufacturer of the specific integrated circuit). Even if you wanted to swap out the ICs on the love board with higher temperature rated components, you may not be able to as not all ICs are available in all temperature ratings (and there are even the odd few that are that have different pinouts and/or incompatible packages for the higher temperature ranges. The connectors may have a different temperature rating. The base PCB would probably be fine as most FR4 circuit board material is rated for up to 130°C. Also, I don't know the temperature ratings of the fans, all the stepper motors, the strain gauge, the LED strips, and even the electronics in the filament sensor (though this could be remediated if you put the insulation blanket over the filament sensor module). I'm trying to think of all the active electronics inside the enclosure volume, I may have missed some.
I haven't done the research, but since this is your project I would suggest that you do the research now that you are alerted to the potential issues. I'm not saying that this is a bad idea, just alerting you to an issue that you don't seem to have considered in the original post here.
Yes, I know that reflow ovens run at higher temperatures than the ratings of components. But not only is that high reflow temperature only for a short duration, the electronics aren't powered up during reflow soldering.
See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
Thanks for the warnings! Although the core of the mod is just 1. A 500c capable hotend, and 2. more chamber temp stability and heating speed, not to raise it past 55c. That would come with the PEEK stuff I mentioned, which I'm very aware would require a vast redesign of almost if not all of the internals! Maybe I could design a semi-full or even full redesign of the Nextruder to mount the Loveboard and in a fully sealed (Cord holes small, too) metal box which is actively watercooled or something quite crazy (Or make a custom waterblock for all components on board too), with the extruder stepper (Alongside X and Y steppers but they're irrelevant for this exact topic) and maybe heatbreak receiving similar watercooling treatment. And the belts probably getting an upgrade to higher temp variants, and modifying all printed parts to be milled out of some kind of metal (Likely aluminum with polyimide tape separators where it mounts to steel alongside some anti-seize on threads to prevent galvanic corrosion). That part (PEEK / 120c chamber) would just be a passion project though, with no promise of me actually looking far into it, simply because I'd never want to even think about buying any kind of materials that would require said upgrades! Currently I'm focused on the two things mentioned at the start, the 500c hotend and chamber heating for temp stability/heating speed (Mainly for stability), but I'd let it heatsoak anyways which would likely negate much of the speed bonus. Interesting topic nonetheless, thanks for bringing it up!
One weak point (which is why Prusa doesn't suggest high chamber temperatures) is the love board. Semiconductors have maximum and minimum temperatures that they are rated for operation, and most commercial grade semiconductors have a max temperature rating of +70°C. See this Wikipedia article. Even most industrial grade semiconductors have a max temperature rating only of +85°C... You would need either military grade (or as mentioned in the Wikipedia article Maxim's Automotive grade or similar from the manufacturer of the specific integrated circuit). Even if you wanted to swap out the ICs on the love board with higher temperature rated components, you may not be able to as not all ICs are available in all temperature ratings (and there are even the odd few that are that have different pinouts and/or incompatible packages for the higher temperature ranges. The connectors may have a different temperature rating. The base PCB would probably be fine as most FR4 circuit board material is rated for up to 130°C. Also, I don't know the temperature ratings of the fans, all the stepper motors, the strain gauge, the LED strips, and even the electronics in the filament sensor (though this could be remediated if you put the insulation blanket over the filament sensor module). I'm trying to think of all the active electronics inside the enclosure volume, I may have missed some.
I haven't done the research, but since this is your project I would suggest that you do the research now that you are alerted to the potential issues. I'm not saying that this is a bad idea, just alerting you to an issue that you don't seem to have considered in the original post here.
Yes, I know that reflow ovens run at higher temperatures than the ratings of components. But not only is that high reflow temperature only for a short duration, the electronics aren't powered up during reflow soldering.
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
500c max is going to be the limit! It's designed for filaments around 320c, but that only means it exists due to needing those temps, not that anything higher will print worse than 320c stuff simply due to the 320c focus. ~320c is all I'm going to use for my personal projects, but higher will be checked for reachability (See the "Verification of functionality and reliability" sections in the roadmap on Github), I just won't be able to test actually printing with ~400-450c filaments like PEI on my own due to not wanting to spend a load of cash on them! Don't worry though, they will absolutely be possible with the max of 500c!
And the cost shouldn't be completely insane like off the shelf printers capable of these things, but in my case it has ended up being around $500-550 USD for solely the upgrades, no base printer, no filament except some PC to print the needed parts like mounts in. Not too cheap, but not $15,000 USD! And you could always leave off some small parts (Will have some way of ranking individual parts by removability without sacrificing much, and have whatever it will affect listed) to save on costs!
And thank you for complimenting the modularity and (future) break down of upgrades, they're both some of the biggest focal points when I designed it! I hope it all goes well for you (Assembly and prints) when it comes time for you to try it out, after everything's finished!
I’m personally trying to do direct print-to-use prints and the material I want to print requires some printing temps above 320 C so I would prefer a maximum temperature of up to 400-450 C. 500 C would be a bonus.
I can only print so many prototypes but need to test the material in autos and in extreme outdoor temperatures. If I print the material it will be made out of then that would be perfect since most printers capable of 500 C with an heated chamber are just too expensive.
I really like the break down of how to do the upgrades too. Very helpful and modular. I really like the heated chamber mod because it’s recommended on some filaments I want to try out.
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
Hotend:
- Upgrade the thermistor to a PT1000 wired directly to the Loveboard, rated for 500c
- Upgrade the heater cartridge to a 65w, rated for 500c one
- Upgrade the nozzle solution to an adapter+V6 one, to make it able to survive at 500c (No native Nextruder nozzles to my knowledge say they're rated for anything above 300c, let alone 500c)
- Upgrade the stock aluminum heaterblock to a plated copper one to survive 500c
- The silicone sock, and all readily available Nextruder socks, to my knowledge, kinda won't survive these temps (Or anything above 300c)! So, we replace it with a few layers of cut exhaust wrap held on by steel zip ties, rated for ~760c and ~1200c respectively! Same purpose, different form, an industrial aesthetic!
What are your thoughts about increased temperatures on the "cold" side of the heatbreak? I would be concerned that the load cell sensor, the stepper motor, and the plastic main plate inside the Nextruder might get uncomfortably hot. There is probably not much you can do to reduce heat conduction across the heatbreak, and limited potential to increase cooling via the heatsink and fan.
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
Hotend:
- Upgrade the thermistor to a PT1000 wired directly to the Loveboard, rated for 500c
- Upgrade the heater cartridge to a 65w, rated for 500c one
- Upgrade the nozzle solution to an adapter+V6 one, to make it able to survive at 500c (No native Nextruder nozzles to my knowledge say they're rated for anything above 300c, let alone 500c)
- Upgrade the stock aluminum heaterblock to a plated copper one to survive 500c
- The silicone sock, and all readily available Nextruder socks, to my knowledge, kinda won't survive these temps (Or anything above 300c)! So, we replace it with a few layers of cut exhaust wrap held on by steel zip ties, rated for ~760c and ~1200c respectively! Same purpose, different form, an industrial aesthetic!
What are your thoughts about increased temperatures on the "cold" side of the heatbreak? I would be concerned that the load cell sensor, the stepper motor, and the plastic main plate inside the Nextruder might get uncomfortably hot. There is probably not much you can do to reduce heat conduction across the heatbreak, and limited potential to increase cooling via the heatsink and fan.
Just got all the parts in today! (Github update momentarily, it'll be updated by the time this post gets through moderation) I tested it, monitoring heatbreak temps after the nozzle was at ~450c for over 10 minutes, with a titanium/copper V6 adapter, and the heatbreak was only at about 44c! Warm, but doesn't seem too bad, and I presume the rest of the parts aren't as hot due to this part being designed around getting heat away from the upper nozzle. Thanks for the consideration though!
I see you included the exhaust wrap solution in the quote too, I'm currently looking for alternatives for it. It's shed fibers all over my printer and it's surroundings! If you do this mod, and to everyone who will, please stray away from fiberous materials like exhaust wrap or ceramic fiber. For your printer, and for your health! Currently reworking my BOM to replace them with safer options if there are any for 500c, stuff like this is why I didn't turn loose my testing BOM just yet! In the meantime I'll test performance without a sock *or* exhaust wrap. More details on Github!
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
I tested it, monitoring heatbreak temps after the nozzle was at ~450c for over 10 minutes, with a titanium/copper V6 adapter, and the heatbreak was only at about 44c!
Well, it would be cool (pun intended) if heatbreak temperature is not a problem. But even with PLA (low nozzle and chamber temperature), heatbreak temperatures in the mid to high 30s have been observed. I am curious what you will measure with actual prints and elevated chamber temperature. Fingers crossed!
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
Agreed! Posted that at 4 AM my time so I forgot about chamber temps, which were practically room temp (~23c reported from what I can remember, so a little above ambient). In a 55c chamber, though, I can guesstimate that the heatbreak will stay ~65-75c if the nozzle's at 450c. I'll of course verify this once I get done printing other parts!
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
This is an interesting project, though for my self its similar to others here. Around 320-330 would be enough to print most high performance materials up to PPS, and it would hopefully not affect the rest of the printer that much. Faster heating of the chamber would definitely be interesting for winter times.
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
New update! Finished the Arduino sketch, finally (5 days of 10+ hours straight each), and made other changes to the readme, and am currently going to upload the current firmware and Arduino sketch (For the Giga R1 Wifi)!
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
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RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
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RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
I have a medium-sized update post for everyone waiting! Progress is great so far!
The images below detail the most important design advancements I've made! They're not everything though, here's the stuff I've done that can't really show in an image:
- Replaced all insulation materials with safer alternatives, except the heaterblock which due to me being unable to source any safe ones rated for 500c+ is being left bare. I have a workaround, in the images!
- Done a decent chunk of modelling CORE One parts in Blender, so I have a solid base to design on
- Done a really large amount of thinking on heat flow and which components get to what temperatures (Mainly the chamber heater / heated base steel plate) and compensated for everything I know about as of now
- Done earlier as noted, but I finished the Arduino sketch! Took me way too long to brute force Arduino Giga USB Hosting even though the final sketch is comparatively super simple
- Discovered my rather strong disliking for PETG (At least Sunlu's elitePETG), every print that comes off this printer, which prints the single best benchys I've ever seen in Prusament PLA (Although I haven't seen too many, I can make out half of the #3DBenchy sign on the back), with the only change the filament and slicer settings to compensate, looks like a stringy, blobby mess that I couldn't even fix up with a pair of pliers and an hour straight, on a small part. A flat part too! It was a prototype for the (literally) big addition to the hotend, viewable below (You'll know it when you see it, it's the mod based on the printhead-cover-right)!
- Semi-detailed in the photos, but a more in depth explanation: Just for context, there are two PSUs! One for the printer, one for the heated chamber. Both are 24v units, one the stock 240w PSU (Relocated to the 200w chamber heater), and the second an LRS-600-24 from Mean Well, a 600w unit, all for the printer's core functions (With 12 AWG wiring everywhere power goes)! Anyways, onto the actual addition, I'm going to have both PSUs independently powered (Feel free to mod the mod to make it take one cable still but that's fully at your own risk and you'll never catch me doing it), but instead of the power switches being on the back of the printer and the bottom as they'd otherwise be, which is inconvenient to use and takes too long to get to to be safe, they're getting rerun to the front of the build! The power connectors are still on the back for cleanliness, but two power switches will be on the bottom-right of the front side of the printer! I personally love the industrial look it'll give and more importantly, the safety (Quick access) and convenience they'll add.
- Probably a whole bunch more I forgot about! There are so many minor adjustments and changes I've made to the design that will make the final product very nice, in my opinion at least.
Hope you all enjoy this update, looking forward to continuing development! It'll be done soon enough, the main limiting factor for me is sourcing the parts (Just ignore the estimated completion date to be honest, I can't reliably predict me being able to source parts). If any of you have any question(s) or suggestion(s), I'm all ears!
Here are the images detailing the more interesting additions:
RE:
Forgot to add the captioned version of the red hot block! Here you all go: (Click for full text, alongside all in the previous post!)
RE:
Good progress, but I have a few caveats. In no particular order:
Your MOSFET board looks like it might collide with the right mounting block for the X gantry, limiting X travel? In general, is it really the best idea to put the MOSFET onto the print head, rather than keeping it outside of the heated chamber? Limited space to place the board, extra moving mass on the print head, higher operating temperatures for the MOSFET.
I am not a big fan of the dual power supplies. Does the one lying flat in the bottom get adequate convection cooling? Do you really want to mess with the primary voltages by re-routing the power switches (in an enclosure that is not properly grounded for electrical safety, since it is designed to see only 24V)? If you can find a single power supply with sufficient rated current and place that in the original position in the back, that would be my preference. Keep the switch in the back -- yes, that is a tad inconvenient, but it will keep the original safety ratings of the PSU intact.
Why do you want aluminum mounting plates for the motors? Better heat conduction to the motors, so they run properly hot? 😉
When you mention the red-hot glowing heater block -- did you actually see that visually, or does it just appear like that in camera images? Cameras will have a bit of IR sensitivity, hence might register deep red at temperatures below 500°C. Actually seeing a red glow by eye would mean temperatures well above 500°C to my knowledge, which would be a bit scary.
Will you rely on the Arduino to close the loop for regulating the hotend temperature? What redundant safety measures do you have in place?
I don't mean to discourage you, but you are biting off a big chunk here. And the resulting device can be dangerous with regards to fire and electrical hazards.
(Nitpick: It's not a "prototype" until you have something physical in hand and can find out about all the surprises where it behaves different from what you expected. Most of what you show is in the "design" stage in the terminology I would use.)
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
Good progress, but I have a few caveats. In no particular order:
Your MOSFET board looks like it might collide with the right mounting block for the X gantry, limiting X travel? In general, is it really the best idea to put the MOSFET onto the print head, rather than keeping it outside of the heated chamber? Limited space to place the board, extra moving mass on the print head, higher operating temperatures for the MOSFET.
I am not a big fan of the dual power supplies. Does the one lying flat in the bottom get adequate convection cooling? Do you really want to mess with the primary voltages by re-routing the power switches (in an enclosure that is not properly grounded for electrical safety, since it is designed to see only 24V)? If you can find a single power supply with sufficient rated current and place that in the original position in the back, that would be my preference. Keep the switch in the back -- yes, that is a tad inconvenient, but it will keep the original safety ratings of the PSU intact.
Why do you want aluminum mounting plates for the motors? Better heat conduction to the motors, so they run properly hot? 😉
When you mention the red-hot glowing heater block -- did you actually see that visually, or does it just appear like that in camera images? Cameras will have a bit of IR sensitivity, hence might register deep red at temperatures below 500°C. Actually seeing a red glow by eye would mean temperatures well above 500°C to my knowledge, which would be a bit scary.
Will you rely on the Arduino to close the loop for regulating the hotend temperature? What redundant safety measures do you have in place?
I don't mean to discourage you, but you are biting off a big chunk here. And the resulting device can be dangerous with regards to fire and electrical hazards.
(Nitpick: It's not a "prototype" until you have something physical in hand and can find out about all the surprises where it behaves different from what you expected. Most of what you show is in the "design" stage in the terminology I would use.)
Thanks for responding so thoroughly! In the order you sent those in, here is what I have to say to each!:
I did actually prototype this one a few times (Just didn't show the images), it collides with nothing more than the stock printhead does! The X gantry block on the right of the printer is actually only about as tall as halfway up the slant on the stock printhead-cover-right, where that slant is both made more lenient and is cutout slightly to give extra clearance, and the board is mounted a decent chunk above this slant! It used to collide with the right variant of whatever you'd call the block at the front holding the tensioned pulleys, but I moved it even farther up and it now clears fine. It also used to collide with the back-right stepper, forgot if that's X or Y, but a cutout in the base printhead-cover-right part of the model has been made and now it doesn't collide! So in short, clearance isn't an issue! And I mainly chose to put it on the printhead instead of elsewhere because it simplifies wire runs greatly. If I didn't, 2 wires have to come off the Loveboard (Original heater port) to control the MOSFET (Listed as the intended wiring of the MOSTFET, to wire directly to something like printbed heater ports that give a constant 24v and modulate GND like the xBuddy passes to the Loveboard), then although it'd simplify running direct 24v and GND from the main PSU, you'd still have to run 2 equivalent wires to reach the heaters, which would still get spliced together as originally intended near the actual printhead (Unless you want to run 4 just for heaters that operate in parallel anyways). I'll definitely look into making an option for that, it's a great suggestion I kinda glossed over when looking at the needed wiring runs!
The bottom PSU (Repurposed Prusa Black PSU) likely has better airflow than it did in the back, to be honest, as all sides rather than the mounting side are exposed directly to room temp air, far away from the printer's heat! If you look at the underside electronics mount, I forgot to add that the little feet that go up with holes in them mount practically flush with the printer's bottom, and extend farther below the printer, holding everything upside down. There's an intended ~14-15mm gap below the PSU from the feet I designed after showing the update, so I feel it has great airflow! Onto the safety part, I did look into this quite far but missed the chamber grounding and overall main tapping safety, however, every bit of the underside electronics has zero contact and is quite far away with a PC-CF insulation in between them and the steel frame. Is this actually adequate? I have no idea! I'll have to look into it further! And I'm also slightly iffy on the dual PSU setup, I simply decided to go with it because it takes the constantly turning on and off 200w load off the printers main PSU, both so the printer can use all the power of its PSU for main functions, and so it doesn't have to deal with anything that comes out of that big-ish load being turned on and off. This allows smaller PSUs to be used instead of anything above ~500w being needed (If we assume the stock printer uses 240w out of its original 240w budget, we add 90w for heaters (130w vs 40), then 200w for the heating pad, giving us a total draw of 530w), won't stress it near its maximum current rating (Unless you buy an insane PSU), and it means you don't have to source a crazy $100+ 24v PSU just to get the needed power budget (At least in my case, anything above 600w is either really expensive or unreliable) alongside having to source more expensive, likely beneficial wires thicker than 12 AWG. I settled with a 600w Mean Well unit since I've heard good about them, and although they're high quality and typically expensive I found my unit for around $70. Anything I looked at with a higher wattage from Mean Well either didn't have terminal outputs, was really really expensive, or both. And about the switch, well, the Mean Well unit actually doesn't have one built in! It already requires you to cut a power cord and bridge the wires individually. So I don't really see why to not put it in the front here for quick access, but will likely have an option for back-mounting the switch, and leaving the Prusa PSU switch on the actual supply instead of relocating it. Really trying to keep this as safe as possible without having to shell out insane amounts of money on just one component (Albeit an important one), as those add up quickly, thanks so much for the concern! If you try hard enough I'm sure it's possible to run everything off one PSU, and will likely include it in the guides for people who want to.
The aluminum mounts are more of a need over a want, the plate they mount to is the one heated to ~150c to heat the chamber! PETG (Or PC-CF) mounts simply won't really like that of course. However, these mounts alongside everything the panel touches, will be thermally insulated from the plate with a multi-layer application of Kapton tape (In the case of the motor mounts, both the plate side and motor side)! And this would include the Z axis linear rod holders, which would get the same aluminum treatment.
And yep, the red glow was visible in person albeit quite faint! The picture was quickly taken out of panic when the printer restarted for thermal runaway, which left the chamber pitch black. That's why it looks more prominent than it is! Included the image of it because it looked cool and interesting in my opinion.
As suggested earlier, the hotend temp will still be regulated by the Loveboard, not the Arduino! To restate, I'll have it where you plug the stock heater port into the MOSTFET control lines for easy usage. This is the recommended wiring by the boards creator, as it's intended to be plugged in somewhere like printbed terminals with a constant 24v but fluctuated GND, which aligns with the xBuddy signals passed through the Loveboard.
No worries! I know that it's a big chunk, doing it all for being able to print PPA-CF at 320c, giving the community a complete overhaul of the printer that lets it print high temps without breaking a sweat, and for a passion project! I honestly love designing this, and working around any issues that arise, especially safety.
(Sorry about that mislabeling! It slipped my mind as I wrote and posted the update at like 5 AM my time. Some were actually in the prototype phase though, just not shown, ex. the external MOSFET mount)
RE: HT CORE One: 500c Nozzle and a Fully Automatic, Inputless, Actively Heated, Insulated Chamber
This is really really cool! Tbh, I will never afford to print those high temp materials, but if I could get my nozzle temp to go from 290 to 320 or 350 I'd be satisfied 😄 I guess that requires a nozzle (since for CF u need a hardened one, saw a pretty cool phateus silicone carbide tip nozzle for about the same price so that seems good) and diffrent thermistor. I'd also isolate the insides, even without heater (unless I'll need to add it) just to help the passive heating. Either way this is awesome and I wish u the best of luck!