FAN3 header DIY filtration possibilities/thoughts
Hi,
I'm working on a DIY Carbon+HEPA filter box, that has enough airflow for PLA, uses the FAN3 header and hopefully also allows redirecting for ABS/ASA.
The main issue is the fan. Maybe you have some ideas or links.
I didn't really find something that would do what I'd want.
Story time:
I printed the little box from CNC-Kitchen, which uses nevermore carbon and a HEPA filter with the cut-out area of the two chamber fans (13 x 5 cm), but the airflow is very poor.
Chamber fans at 75% (sounding like an aircraft), still 33°C in the chamber after 30 minutes of printing PLA at 215/55.
So the chamber fans need quite some help and the area of the HEPA/carbon needs to be as big as possible to reduce the needed pressure.
https://www.printables.com/model/1187562-core-one-hepa-charcoal-filter
My thoughts:
The Alveo3D fan from all Prusa filters is a 12032 radial fan with 24V/0.5A.
Sadly, they only sell a non-PWM version and a PWM version with 1.0A.
Prusa Support couldn't tell me the maximum current the fan header can take, so I don't want to risk it.. It also wouldn't have the Molex Clik-Mate.
Then there's the fan of the MKx/Mini filtration box in the Prusa-Shop, which costs about 50€ and the fan for the XL enclosure, which seems to be absolutely identical, but costs 31€.
Support says it's not identical, but the rear stickers in the manuals are identical, as are the connectors. And they look identical to the Core One fan headers.
There's no fan for the Core One filtration kit yet, but the pictures look identically again.
And then there are a bunch of 12032, 24V fans out there, many without listing the Amperes, pin count and connector.
I also thought about using an axial fan, like the Noctua industrial 140 mm: 24V, PWM, below 0.5A.
But although the CFM are way better, the static pressure is very poor and probably wouldn't be enough no matter the filter area.
I'm a bit annoyed about the "special" 24V/0.5A specs combined with the Molex Clik-Mate 1.5.
The XL fan + shipping costs 40€ and to me, it looks like it's "just" one of these identical no-name 12032 24V fans from China, with the impeller missing the small bridges from the center to the blades and a Clik-Mate connector.
Paying 3-4x (or 6x, if you buy the MKx/Mini fan) because of missing specs of the fan header and a 2,50€ connector.
Using one of the "Bambu/Voron" 24V fans would be a lot cheaper, but they are 0.8-1.0 A.
----------------------------------
So I guess I'm getting the XL Enclosure fan, put 2-3 of the HEPA filters next to each other (10/15 x 13 cm), fill it with nevermore and think about some design to redirect the air back into the printer.
Maybe one of the holes of the Core One can be used or a magnetic hose from the rear to the intake at the top.
Or one could replace the stock chamber fans with two printed 90° curves, using one for exhaust, the other to switch between exhaust/redirecting, since I'm not sure if they'd be helping the 12032 filter-fan anyway, creating some circular airflow through the filter.
Or putting a smaller blower fan on one cut-out and a 90° redirection on the other.
Does one of you know of a blower fan with a 4-pin Clik-Mate connector?
When done, I'll share it, ofc.
RE: FAN3 header DIY filtration possibilities/thoughts
I've also been giving this some thought, specifically with the assistance of the Hackerboard to directly inform some additional hardware to open/close the top vent, redirect between filtering and exhausting, etc.
The connector is honestly one of the trickiest bits. I've considered just buying more fans to cut the connectors off but that's $10 plus shipping. I've not found any sources able to provide them pre-terminated at a better cost though, so maybe that's the best option besides bypassing it completely and using an independent system that doesn't rely on the in-built temp management, but I'd really prefer just to augment.
To me, the perfect DIY is a recirculating filter (Nevermore style) with the option to selectively exhaust on the post-filter side. Then you still get the single pass filtering in temp-regulation, but most of the air is being repeatedly scrubbed and kept inside. For PLA you could just fully exhaust and open the front vent (working on a servo operated version atm). But for that all to be happy, I think you'd need to be able to independently control how the chamber and filter fans act, and preferably be able to use completely different fans. But between the lack of specifications on the extension board ports and the near impossible to find connectors, it's really shutting out a lot of options...
Let me know if you find out anything more!
RE: FAN3 header DIY filtration possibilities/thoughts
The connector is honestly one of the trickiest bits.
Look at Mouser and DigiKey, search for 'Clik-Mate'. Both offer pre-made cable assemblies in lengths to 600mm for $2-$4.
RE: FAN3 header DIY filtration possibilities/thoughts
I ordered a few of these: https://www.mouser.com/ProductDetail/Molex/15135-0403?qs=jFK2DQXLaBw2%252ByyM%252BREUeQ%3D%3D&countryCode=US¤cyCode=USD
Then you can just cut the cables in half to get tails and don't need to have everything on hand to crimp these connectors.
RE: FAN3 header DIY filtration possibilities/thoughts
Is the FAN3 connector a 4-pin or 6-pin? Looking on the xBuddyExtension schematic, looks like 6...
RE: FAN3 header DIY filtration possibilities/thoughts
Oops, FAN3 is surely 4-pin, my error...
RE: FAN3 header DIY filtration possibilities/thoughts
Assuming one has both the connector that Prusa uses (clik-mate from Mouser for example) and a standard PC fan, where do you get the pinouts from to splice the two cables together?
I'm working on my own version of the filter from Printables (cited above), modified to move the filter above the printer to reduce the space needed behind the printer (and reduced wall thickness to improve print times).