Fumes?

Hi all,

Since I didn't want to hijack the thread on Mendel90 enclosures, I thought I'd start a separate thread on controlling the fumes. I'm too planning to build an enclosure for a while now. But what I want to add is a fume extraction mechanism. I've already read a study stating that a desktop 3d printer can be labelled as a "high emitter" of nano sized particles which could be harmful. Since I'm always close to the printer I think I should take care of this risk. So I was thinking of attaching a fan to some air-duct material. But I'm a bit worried about creating a draft inside the print chamber which could disturb the printing process. Is there a smart way for dealing with this?

Regards,

Nilez

The only thoughts I have are that the hot-end fan will push the fumes down towards the heated bed and they will circulate everywhere from there. I think it might be an idea to vent the case at the centre-rear and let clean air in at the top of the case. A low airflow should prevent too much breeze effect and the incoming cool air will mix with any rising warmer air. I am not sure that the conventional wisdom of pulling the air out of the case top is a good idea when you consider the machine structure and existing forced airflow.

Regards,
Neil Darlow

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I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.

Sounds very plausible Neil. Thanks!

Does PLA pose the same risk or is it just ABS? If you don't use the fan with ABS (I find that I don't need it) and if the toxicity only applies to this material then the standard overhead fume extraction method won't be such a problem as there won't be a force airflow near the bed to play havoc with the fluid dynamics...

Also, if it's just extraction you need rather than temperature control then is it viable to just have a hood and fan duct above the printer to remove the majority of the fumes?

Hi QP,

Here's a link to one of the papers: [www.sciencedirect.com]. It concerns the emission of UFP (ultra fine particles) caused by the heating of PLA as well as ABS. Although ABS emits 10 times more. Apart from the fumes, I need to build an enclosure to keep heat in because I'm moving my printer to a garage space.

How about an enclosure + this carbon filter ?

Is there a TL;DR version which compares the relative toxicity of PLA/ABS nano-particles with say, sitting next to a laser printer, or having the window open next to a busy city street or even just in an office that has air-conditioning? I'm not disputing the science - it'd just be nice if they produced versions for those of us who don't have a solid background in what is considered "normal"...

[www.youtube.com]

Quote
neildarlow
The only thoughts I have are that the hot-end fan will push the fumes down towards the heated bed and they will circulate everywhere from there. I think it might be an idea to vent the case at the centre-rear and let clean air in at the top of the case. A low airflow should prevent too much breeze effect and the incoming cool air will mix with any rising warmer air. I am not sure that the conventional wisdom of pulling the air out of the case top is a good idea when you consider the machine structure and existing forced airflow.

Regards,
Neil Darlow

Just thinking out loud for a moment - would either a reversible fan (if such a thing exists) or a push/pull configuration where only one is active at a time, located where the current bed fan is mounted be a suitable solution to this?
I'm guessing that for most enclosures people have simply blanked out the existing bed fan intake - if this could be done instead then we don't lose the use of a bed cooling fan?