Improved Core ONE Fan Shroud?
I have noticed a tendency for overhangs facing the chamber doors (the side opposite the fan shroud) to slightly sag, even when using supports. It is not critical, but I see it and it annoys the hell out of me.
If I print the same model rotated by 180°, it comes out fine - but then the issue manifests on the opposing side, if there are some overhangs. This happens even with the chamber door open, so it is not an issue of the environment being too hot, but rather the air not properly reaching the filament on the side facing away from the fan shroud.
I tested this with the stock silicone sock and the stock 0.4 mm HF nozzle across different printing profiles, using various materials and brands. As an experienced Prusa user since the MK2, noob mistakes can be safely ruled out.
The "blowing-on-water" test results in a fairly acceptable pattern, but the issue still manifests during actual prints. (For those unfamiliar, this test involves pouring water into a small bowl and placing it underneath the print head to see where the fan actually blows; ideally, it should show a concentric, circular indentation centered directly underneath the nozzle).
I will post an example photo when I come back home.
Has anyone else noticed this or perhaps designed an improved fan shroud? I haven't found one yet.
RE: Improved Core ONE Fan Shroud?
I have certainly experienced the same -- the "360° cooling" Prusa advertises for the Nextruder needs to be taken with a grain of salt.
But I have not come across any improved designs. It's probably not easy to achieve more even airflow distribution with a single fan. The air path from back to front will always be longer, and you want to retain some visibility of the nozzle tip and access for swapping the nozzle.
RE: Improved Core ONE Fan Shroud?
I have certainly experienced the same -- the "360° cooling" Prusa advertises for the Nextruder needs to be taken with a grain of salt.
But I have not come across any improved designs. It's probably not easy to achieve more even airflow distribution with a single fan. The air path from back to front will always be longer, and you want to retain some visibility of the nozzle tip and access for swapping the nozzle.
There is also one counter-intuitive issue with this concept: increasing the fan speed might actually worsen the effect, as the air might blow the filament away from the nozzle.
RE: Improved Core ONE Fan Shroud?
There is also one counter-intuitive issue with this concept: increasing the fan speed might actually worsen the effect, as the air might blow the filament away from the nozzle.
And you will probably get into the regime of turbulent airflow soon, where all bets are off... The overall flow might actually drop due to increased resistance, and the spatial distribution will be hard to predict.