High temperature hardware modifications?
I'm about to pull the trigger on a Mk4, but I need to make sure that it can survive a few minor changes, to suit my purpose (I'm wanting to print high temp nylon. Specifically either Essentium HTN CF-25 or 3DXTECH HTN+CF). I currently have a Mk3, and I have acquired a high temperature thermistor (pt1000) and a bondtech CHT nozzle. I have it all in a lightly modified Lack enclosure, where the highest temp I've gotten was 113° F. I was planning on replacing the printed parts in the Mk3 with Prusa CF-Nylon, when I did the thermistor and nozzle change, but now I think I'll just get the Mk4 kit, and print the necessary parts on the Mk3 (in CF-Nylon), and sell the Mk3.
That leads to the questions:
1. Can the electronics (aside from the PSU, which will be outside the enclosure) still survive 105-113°F (40-45°C )?
2. Can I use the PT1000 on the Mk4? I'm assuming that I'll need to cut and splice wires, to make it work, and that's fine, if that's the case.
3. Is it significantly harder than the Mk3, to edit the thermistor tables, to allow the hotend to get up to ~310° C, and the bed up to ~130° C?
4. Will the nylon-coated build plate suffer at 130° C?
Thanks in advance!
RE: High temperature hardware modifications?
After chatting with Prusa tech support, and looking at the github repos, it looks like this isn't currently possible, since the Mk4 firmware hasn't been released, yet, so I can't change the parameters to match the PT1000, regardless of whether or not it fits, nor can I raise the bed temp max to 130.
Still don't have answers on the nylon build plate, nor the max temp of the electronics, though.
RE: High temperature hardware modifications?
Where did you get info about a nylon coated build plate ? The MK4 build plate is essentially the same as those on the Mk3, those are PEI coated steel sheet. Either a PEI sticker for the smooth ones or powder coated application for the textured and satin versions. They are not nylon.
RE: High temperature hardware modifications?
Where have you been lately ? 😉
Prusa released a nylon coated steel plate several months ago. It's intended to be used solely with nylon filaments and cleaned only with water. No IPA, acetone or any kind of adhesive.
https://www.prusa3d.com/product/double-sided-powder-coated-pa-nylon-spring-steel-sheet/
RE: High temperature hardware modifications?
Obviously not on the shop lol. That one completely passed me by.
Now I'm wondering if the bed can actually manage 130 degrees anyway, it struggles enough with 100 degrees. Although Id guess in the enclosure it should have a better chance.
As for electronics, the most temperature sensitive components tend to be the capacitors. They generally are rated 60-85 degrees but like any electronics part the hotter you run them the shorter their lifespan. You can get extended range parts but they are more money naturally and are used for military/aerospace and other industrial type boards. I'd be surprised if Prusa opted for those.
I wouldn't run any board above 40 degrees personally but if you are running at the temps you listed above then almost all electronics would be fine. An enclosure for the hotter materials though can quite easily exceed those temps, especially on long prints. My crappy lack enclosure can get to 50-55 when printing ABS which was why I jury rigged a blower fan to force air across the board of my mk3 when I did so. Figured it couldn't hurt and wasn't blowing on the part to mess that up.
RE: High temperature hardware modifications?
Look in this video at 01:20 min:
He can set the heatbed temp to 140 °C !
RE: High temperature hardware modifications?
I looked into the data sheet of this Essentium material and it says nozzle temp 270 - 290 °C. Why do you think you need 310°C ?
Heatbed also recommended 60-80 °C ...
RE: High temperature hardware modifications?
As for electronics, the most temperature sensitive components tend to be the capacitors. They generally are rated 60-85 degrees but like any electronics part the hotter you run them the shorter their lifespan. You can get extended range parts but they are more money naturally and are used for military/aerospace and other industrial type boards. I'd be surprised if Prusa opted for those.
I wouldn't run any board above 40 degrees personally but if you are running at the temps you listed above then almost all electronics would be fine. An enclosure for the hotter materials though can quite easily exceed those temps, especially on long prints. My crappy lack enclosure can get to 50-55 when printing ABS which was why I jury rigged a blower fan to force air across the board of my mk3 when I did so. Figured it couldn't hurt and wasn't blowing on the part to mess that up.
In a previous discussion regarding the Mk3, a Prusa rep said that the electronics were good to 45C, continuous. I have adjusted airflow to the enclosure to make sure I do not exceed that. I want to make sure that the new screen etc. doesn't have a lower "long term survivable" temperature.
Look in this video at 01:20 min:
He can set the heatbed temp to 140 °C !
That is VERY interesting, indeed! Thanks for that!
I looked into the data sheet of this Essentium material and it says nozzle temp 270 - 290 °C. Why do you think you need 310°C ?
Heatbed also recommended 60-80 °C ...
You're not wrong about the Essentium, but the 3DXTECH HTN has a 21°C higher heat deflection temperature, and if I'm putting the effort into using high temp nylon, I want every little bit I can get. If I can't get the printer to handle that material, then yeah, I'll settle for the Essentium.
Take a look at the 3DXTECH CF-HTN page and data sheet. They suggest 285-315°C extruder temperature, with a 110-120°C bed temp, BUT, in the actual TDS, for part samples that they tested, they used a bed temp of 130°C and an extruder temp of 295°C.
We now know that 140°C is available for the bed (assuming you have enough chamber temperature or insulation to get there). The current firmware does not allow for a 295°C hotend, and if they're using the same or similar thermistor in the hotend, then it's getting to be REALLY small changes in resistance at that temperature, and should be replaced with something that has a wider range, so you can accurately hold 295+, if you want to do heavy work in that material.