Sovol suggest printing with PETG the doors should be left open, apparently the heat soak with doors closed causes models to sag. And confirmed by several others with good experience. I am waiting for my Max to despatch (ex AU store), first printer owned, and trying to get all the prep done while wait (Noctua fans coming, post processing, hoto tools, etc).
The printer will be set up in my home office to run demo prototype prints of 60:1 scaled mining machinery, think of a cross between a mobile crane and a bulldozer. They will be around 500mm long, 400mm wide, 350mm high in a few variants, and I have 30kg of PETG âto goâ.
Leaving the doors open for lengthy prints is just going to be annoying, so the idea of case fans for ventilation quickly comes to mind, either two or four. May need their own thermocouple control circuit, it is an important detail to look into. But first, an accoustic filter of some kind needs to happen as putting 24V Noctua fans on there may be quiet, helped by the Noctuaâs on the printhead etc, but all the buzzing and whirring will have open passage to annoy.
Has anyone attempted to solve this problem? And would it even work to ventilate to avoid sag? Or is this my own little journey of discovery I need to go on� Thank you.
My post wonât have anything to do with the MAXâŚ
You said this is your 1st printerâŚI wouldnât change anything for 2-4 weeks.
I think you need to get used to printing & the printer first.
If you start adding & removing features right away & have issues, they will make it harder to figure out..was the issue already there or did you cause it..??
So get used to the printer, print things, make mistakes, get a feel for what you might or might not want to changeâŚJMO
Whilst I am a little at risk of âoverthinking itâ, I have built a lot of âstuffâ in my time and have no drama processing a predictable situation and dealing with it. In the engineering game, we call that planning⌠If there is shared experience out there that deals with the obvious situation (PETG sagging, so forget about using the enclosure doors to cut the noise back a bit), I am grateful for that and will happily integrate the knowledge. I am not looking for life tips .
Question: Do you know of a way to cool the enclosure without a lot of noise leakage so PETG could be printed in an occupied room (my home office)? There will be 24V Noctua fans for this, and setting up a thermocouple to trigger them (either two or four fans) is doable, but an acoustic intake on the fans to keep the noise from getting out is probably a job to do, if this problem isnât already solved. Or is enclosure ventilation unlikely to be reliable enough to prevent sag with PETG? Or am I over-thinking it! Thank you again.
Answer: Yes, you often can print PETG successfully with the doors closed. The stock dual part-cooling on the MAXâs toolhead is quite effective for most prints. Youâd really only need to crack the doors open for models with extreme overhangs or lots of bridging. For PLA, however, youâll almost always want the doors open due to its lower melting point.
Your idea about adding thermostatically controlled Noctua fans is exactly where an engineerâs mind would go. The challenge, as youâve correctly identified, is the SV08âs âflying gantryâ design. On drop-bed printers, itâs easier to add external cooling fans. Other printers solve this with complex airflow (like the Creality K2âs curtain fan) or even active venting (like the Bambu H2S), but itâs much harder to implement on a moving gantry.
Over-thinking it? Probably a little, yes While building a custom acoustic ventilation system is a fascinating project, the bigger concern is air quality. My strongest recommendation would be to prioritize finding a place for the printer outside of your immediate workspace. Even PLA and PETG release VOCs (Volatile Organic Compounds) and ultrafine particles when melted. For a home office where you spend a lot of time, itâs much safer to have the printer in a separate, well-ventilated room (like a garage, workshop, or a spare room with an air purifier/vent). That single move solves both the noise and the air quality problem at once.
Itâs a great path youâre on with all the prep work! Keep the great questions coming!
I like the smell myself, to me it smells like Maple Syrup.
I have a friend who canât smell it.
It was just something else to think about if you have it in the office with you.
Iâve done exactly what you propose and for pretty much the same reasons â the MAX already has a massive footprint. Opening the doors just makes it bigger. And closing the doors helps mute the sound of the steppers and extruder fan. Somewhat. Nothing will ever make this printer quiet but youâll eventually get used to the rhythmic sound of the buffer feeding, like ocean waves breaking on the beach. Worry when it goes quiet!
I designed and printed this snap-on 4â/100mm dryer duct hose adapter for the exhaust (upper) fan:
so I can run a hose to a nearby window (I printed a companion part that fits in the window â but of course, it only fits my window ).
I added a couple of lines of g-code in my Orca filament definitions for PLA and PETG that turn on the fans to 30% when starting the print and off again when the print is finished. I found that the 30% figure works well in my environment, keeping the chamber temperature down to ~ 25°-28° with a bed temp of 60°C.
My current version is printed in ABS just to handle the higher heat when I print ABS, Nylon and ASA without warping but thereâs no real reason it canât be printed in PLA or PETG. With the fans off the highest temp the chamber sees is still less than 60° with a bed temp of 100°.
All that said, you will not get the required precision out of the printer as shipped. Filaments expand and contract at different rates, etc. You need to have closely tuned your printer and filament settings â in particular your X-Y shrinkage and Z-shrinkage â in order to achieve a snap-fit. But youâll want to do that anyway if you are printing scale models.
Note: most shrinkage test prints use small cubes. They are not sufficiently precise for the large MAX bed, but scaling them up increases print time and material use exponentially. I designed this quick and dirty (but highly accurate) model for use with the MAX (or any other large bed printer) :
do you calibrate dimensions by measuring both widths and lengths of your modelâs beams and inserting values into the 2 equations(for length and width) system with 2 variables (xy shrinkage [%] and xy compensation [%])?
Wait for it to cool. Measure X. Measure Y. Hopefully they are identical, if not, average them. Divide by 3 (since they are 300mm long). Enter the value under the XY Shrinkage Compensation for the filament. Do the same with the Z axis (divide by 3 if you used the 300mm tall version, leave as is if you printed the 100mm tall version) entering it under the Z Shrinkage Compensation value.
X-Y hole and X-Y Contour compensation (under the process settings) is separate and should be done after the shrinkage. Use the Orca hole compensation âHandy Modelâ for that.
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