A replicator 2/2X air scrubber that really works..

by RodLaird Jul 30, 2013
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Has anyone tried wiring the fan directly into the MakerBot Replicator? Considering how powerful the supply is, I can't imagine it would impact the printer's performance much if at all. I would like to make it so that the filter is always on when the printer is on and reduce the number of wires needed. If the fan uses the most power when first turning on, that should be fine as the printer uses the most power when preheating the bed and extruders, right?

Does anyone see any issue with wiring the fan up in this way?

Hi Rod,
I'm using the same fan and filter but the airflow is so low, it couldn't blow a candle out. Is that what you're getting?

Hi there! I get a reasonable airflow. You can feel it with your fingers but its no stiff breeze. The point is only to create a gentle airflow out of the case. If you carefully seal the lid and other top holes you create a small negative pressure inside the case that ensures there are no major fume leaks. The filters have a modest air resistance but the fan i use generates a good static pressure and in fact i never run the fan at anything like rated power. Check the static pressure of the fan i guess and that the filter canister does allow air through easily. (Cup yiur hands and breathe through it). Honestly cannot imagine what could be wrong unless you are way underpowerung the fan

quick question, not a native english speaker, but what is a "cum suspension system"? I am too scared to google that at work for obvious reasons...

Lolz. In this context cum means "sort of like a"

There is a square piece that prints with the Exhaust.stl. Can someone tell me what is is for??

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Great design!

Has anyone from Europe built and is using this scrubber?

If so, what filter cartridge do you use and found to work?

I've come across some different brands (eg: Willson), though due to cost, I would rather go with a tried and tested cartridge if possible. Just in the case the one I end up buying ends up too dense to effectively /pull/push air through.


i'd also be much interested in a source for the filter in Europe!

Any idea how much more restrictive the Neiko 53885A is than the filter listed for AU?

No idea; but the specified fan is very powerful. (I turn it down a lot). you are not looking to create a breeze here; just a modest airflow that maintains an negative internal pressure in the case. I would be confident that the filter would work; but in the end there cannot be much opportunity cost to just trying it eh?

Is there a cheaper alternative for the fan? The one in the link comes to $60 after shipping :(

Sounds about right but I am not in the business of sourcing parts; Mr Google is your shopping friend.... The fan needs to be able to deliver considerable pressure differential; this is not something that cheap fans do...

Thanks for the reply. I've scoured google and can't find anything cheaper that delivers the same pressure. One more question; I'm doing the majority of my prints in PETG, is there any reason this wouldn't work with PETG or other materials I might print in the future e.g. nylon?

Should be absolutely fine

I have my printer build into a small Ikea closet (60x50x64cm). Assuming I could make the closet air tight, would the airscrubber be effective enough to cleanse the air in this space, even though it is a bit larger?

As I understand it, you can increase fan pressure by stacking fans, so couldn't you build this with 2-3 cheaper and more widely available CPU fans? To find out how many fans you need, just stack more on until it pushes the air through! http://www.overclockers.com/fan-stacking-myth-vs-reality/

Is the RC56 filter supposed to fit inside the adapter that goes to the fan? Or is it supposed to butt up against it? I've got the exact same filter that is pictured.

I'm struggling with scaling on my printer, I'm not sure if the problem is my printer or the part itself. My filter cartridge has an external diameter at the outlet of 69.6mm, and the adapter ring printed out at around 67.5mm diameter.

Can anyone shed some light on this issue for me please?

I've just opened the file in meshmixer, and have measured the internal diameter of the adapter ring. It turns out to be ~67.6 mm in diameter.

Can someone who has built this thing PLEASE tell me how the filter mates with the adapter ring?

Thanks in advance.

You can see in the photos that the filter sits neatly inside the adapter ring...

I calibrated my printer carefully and the design was set to be a moderate tight fit based on filter measurements. The printed adapters just fitted for me.

I am overseas and not in a position to revalidate any of the measurements for 3 weeks

Hi Rod,

Have you had a chance to measure the diameter of your filter where it mates with the fan housing? I'm keen to build this fan housing, and have spent weeks calibrating my printer so that it prints perfectly -- mainly to print this scrubber.

Just back now from the US. Inflow dia is 66.5mm and outflow 69.4mm. Fits in my design...

Thanks Rod, I appreciate your reply. I just can't see how my filter would fit in there. Maybe they've changed the dimensions of those filters or something. I look forward to hearing from you when you've had a chance to measure your filter.

Well, I've finally managed to build this device. I had to scale the adapter that goes between the filter and the motor by 103%, and also scale the adapter that goes on the other end of the filter by 95%. As far as I can tell, the parts as designed pull air the wrong way through the filter. Printing at those scales means that the filter can be oriented the right way, to suck air from the inflow (small diameter) to the outflow of the filter (larger diameter).

I used silicone tape (self healing stuff from the plumbing department) as the motor seal, it works really well.

I've got it running on 7.5V and it's a little champion, pulling air through the filter just fine. At 12V it sounds like a jet taking off! Those fans are amazing. I got 5 surplus from some servers. The rubber band system works an absolute treat, it's a great design.

Can't wait to build an enclosure for my printers and stick this puppy inside.

Comments deleted.

Ok, So I've made one of these and because I'm in the US had to use the Neiko 53885A filter along with a Delta PFB0612UHE blower. The specs on this blower ROCK (http://www.delta.com.tw/product/cp/dcfans/download/pdf/PFB/PFB60x60x38mm.pdf) (has better specs than the Orion), but even with those specs it's not moving enough air through that filter to create a negative pressure gradient in my FFCP. Not even close, even when powered at maximum. (which is ridiculously loud)

What gives??

Hmmm; the spec's look good indeed. I get a reasonable airflow through the filter with mine operating at way less than full power. I have gone to some trouble to ensure all of the top of my Rep2X is sealed off with plugs in the corners and reasonably closely sealed covers on the rear of the lid. Air of course comes in through 3 bottom corners of the Rep2X space and of course one of those is the exhaust for the fan. I don't expect to have a huge negative pressure - just enough to ensure a net outflow in a space that is "loosely sealed". The proof of the pudding is in the eating - and in this case the result is that you cannot smell any ABS fumes when the fan is running... After sealing the case as much as you can, just try the system with a moderate speed fan and see how the sniff test goes...

Thanks for the suggestion RodLaird. The ABS filament I'm currently using doesn't have an odor, at least not that I'm able to detect. (or my wife)

I'm thinking the Neiko 53885A filter maybe somehow much more restrictive then yours. I'm going to borrow a vane anemometer from work and see exactly how much air this is moving. From my knee jerk guess, I would say < 3 cfm (I literally can't feel any air moving across my cheek on the intake side of the filter.)

So at this point even If I was able to seal every single air leak in the entire case, the air scrubber would not be able to overcome the natural hot air convection through the Plexiglas top that I would guess the nano particles would be riding on.

Did you seal those corners from the inside?
Not sure what kind of top you have, but how did you seal yours up? Silicone?

On the FFCP, it will literally require disassembly of unit to seal the upper corners from the inside, something I'm not at all excited about doing.. :-)

Sounds like sensible steps. There is another thingiverse project I did which prints sealer caps for the Rep2X corners and also a lid hinge that you can also add sealers to. I would just bung some bluetack in the holes while you are investigating. My filters deliver a steady output airflow which is easy to detect. the inflow is more difficult due to the surface area of the filter...

As I suspected, very little air volume moving through my R-621 Respirator Filter. Here's a video I made on it. The best I could get through it was ~8 cfm running at 12vdc. Since you and others have seen great results, I suspect that this filter is far more restrictive that yours.


So I think my next step will be a HEPA filter. What do you think about using HEPA?

I think you need an activated carbon filter so that the polar ABS nano-particles "stick"; I am not sure that HEPA filters are other than micro-particulate filters...

Thank you so much for your work on this. I recently made an adapter to fit your scrubber for the 3M filters. http://www.thingiverse.com/thing:1000752 Thank you again!

3m organic vapor adapter for RodLaird's Rep2/2X Scrubber
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Fantastic - well done!

Is there any reason why the filters from something like this would not work (once fitted properly):

Basically you just want an activated carbon filter, right? Nothing fancy; or is the quality of the filter important?
I assume since this is a low volume/low pollutant application, the filter is not heavily burdened...

Did you really have to make the RepScrubberCoupler.stl include 3 parts all panelized like that? Thats about 10" long, some don't have that much length to work with and its frustrating since its 3 parts that could be easily separated. And no I'm not too lazy to split an STL, I just don't know how. I just got my printer a couple weeks ago and outside of generating an STL from Solidoworks and OpenSCAD I have no clue how to do much with them other than print.

Anyways after further research it looks like acquiring the filter will be a problem so I'm going to look for another design unfortunately. I really like this one but I'm not paying that much to ship the filters from Australia. A great design with a couple hang ups preventing its practical use and printing by me. Still a thumbs up for the solid engineering!

I think you will find in the comments below (seek Jake), links to adaptions of the design to suit filters available in Europe and NA...

...and on the STLs; manipulating them is a basic skill worth learning! I have no doubt that you will as you ramp up the learning curve associated with 3D printing. Enjoy. "Live long and Print"

Thanks, I found one! Filters are already ordered. Now if I Can split this damn part. Netfabb is way too expensive but I just found Autodesk Meshmixer. I am willing to take recommendations of other programs but so far I am impressed with Meshmixer!

OK - I have split and uploaded the components for you. I would look at blender (http://www.blender.org/) if you want free software that is versatile. The focus of meshmixer on meshes alone is a bit of a problem. Be warned that (like any powerful 3D software) Blender has a considerable learning curve.

For what it's worth I have used many different 3D programmes (most pretty expensive) and for this class of work have settled on Rhino3D as ideal - in no small part because of its very productive interface, powerful toolset, and, above all, its geometry programming language, Grasshopper. Not much out there with so much power. (OpenSCAD has some strengths - but very klunky and nowhere near as powerful / productive) Guess that's what you get if you are not willing to invest some $$

In the end you will have to invest considerable time learning the tools if you want to create interesting things...

You can also use TinkerCAD (www.tinkercad.com), which is a free, very basic, browser based modeling tool. I use it to split .stl files into multiple parts for easier printing all the time. I've also made a few original items as well.

Does anyone have Amazon links or Part names for non printed parts? I will be ordering a reprap kit soon and my wife wants an enclosure built asap and I think this would be a great thing to add to the enclosure. We tend to order everything from Amazon so that is why I am wanting to source all non printed parts from there if possible.

Check out Jake's comment below for a link to his mod to fit filter parts available on Amazon

I read the linked medical article. Not to be a denier or anything, but there is no real proof that these particles are dangerous, and in fact, 3D printers are less of an emitter than cooking on a gas grill (source the same linked article). In fact I've read the exact opposite, that the emissions of ABS and PLA are benign when melted at the temperatures typical of 3D printing. They become dangerous at much higher temperatures because they begin to burn. That's when they get toxic.

God forbid there is anything to this, because if there is, a lot of 3D printer companies are going to get sued out of existence.

Hi BillyD

I'm a Biomedical Engineering Professor active in the nano-technology domain. Nano-particulates are quite capable of infiltrating DNA, raising the prospect of epigenetic effects separate from any chemical toxicity that may result from combustion products. The jury is still very much out on which nano-particulates may be of some concern in this regard. And it may be many years before the evidence is there to clarify this. So it would seem to be prudent to apply the precautionary principle. Ventilate very well in any case - and if you can, reduce the emitted particulates with barriers / filters.

I would note that there is a strong emphasis on PLA printers now in the enthusiast markets by the larger printer companies. I regard this as no accident; PLA produces less aerosol particulates per se. My direct correspondence with Makerbot on this issue suggests they are very reluctant indeed to make more than generic statements about prospective hazard; I surmise for the reasons I outlined above.

You are right to be sceptical - stay that way (and minimise inhalation of printer pollutants!).



Thanks for your Reply Rod. Well now you've gone and done it. I went from thinking you might be misguided to quickly realizing I was the misguided one lol.

I just downloaded your scrubber. Thanks for this. I am going to take this more seriously until we know more one way or the other.

Just to be clear this device just sits inside the printer (within an enclosure) and filters the air via dc fan. You are not actually sealing anything and creating ductwork, correct? My R2 does have a full enclosure (as is required to print ABS), but it is not airtight by any means. Should I seal it up too?

No probs! It does indeed fit in the enclosure and pushes air out of the rear left corner cuttout. Airtight is not a requirement, this generally creates a negative pressure in the enclosure enough keep things clear. (Depends on fan speed; the tighter the enclosure, the lower the fan speed required to do so.)

You might also look at my corner plugs (for the 2X unfortunately) that turn out on their own to stop a lot of the convective "stink" loss. I cannot remember my old R2 so I am not sure whether there is a similar vertical vent that needs plugging up. (I was surprised when I produced these, that they reduced a huge amount of venting even without the scrubber).

Use in well ventilated area too in any case!

Would it make sense to seal the enclosure as best you can, and just run the filter to recirculate the air in the printer enclosure? Then you don't have "cold" air rushing in to possibly spoil the print. This would reduce the nanoparticles escaping the printer also would it not, since most would get captured in the filter.

The air you need to move is just enough to keep a negative pressure gradient, so it is not like it's "blowing a gale"! I guarantee that it will not draw in enough cool air to affect the print in any way.

OT, here in Oz the problem in summer is keeping the print volume cool enough for the extruders not to fail. Once the interior temperature gets over 50'C, the filament pinch wheels can start to have problems (they are significantly higher temperature) that the air. This limits sustained printing with the lid on to under 35'C ambient....

Last question. A few comments down someone suggests a Neiko filter as something that is available outside of AU. Is that adequate for the nano-particles? It seems more suited to removing the smell of the vapors which I believe is certainly benign, vs the nano-particles your link discusses which may or may not be a health hazard.

I would imagine the prefix nano refers to particles that are very small. And that many filters wouldn't even closely be suitable for that task.

Seems like you'd want a p100 type filter, and then possibly additional filtering if the smell was of concern. I think they make filters that do both, but I don't see where the Neiko filters addresses particulate in any way. Unless it is implied in some way.

I think you'll find that activated charcoal based filters will do a good job. The particulates are reasonably polar I believe and have a good affinity to the carbon... ;-)

Just wanted to say this is a really nice design. I was able to buy everything else I needed on amazon. Found a 1v to 12v variable 2A power supply for $8.99. Added a rocker switch which I will mount right to the makerbot to turn the fan on and off. Magnets, filters on Amazon too. Went with the Neiko brand mentioned elsewhere in this comment section and the alternate prints for same.

Already have the printed parts finished and received the fan from digikey. Like you said in your write-up I too am always amazed at how accurate these printers are. The fan fit perfectly. Like someone hand made it to fit. Got to love 0.2mm tolerances in manufacturing at the press of a button. These truly are amazing machines.

Super - very pleased - mine just works... (Needs new elastic bands every now and then as they degrade with the build chamber heat. Not worth finding silicone ones; rubber bands are cheap!

I have been looking something to help me with this problem. This design is fantastic, thank you for sharing.

You are welcome! I hope it works for you. Mine continues to work flawlessly which is nice in our normally SNAFU world... LOLz Indeed, with the in-line filament cleaner my printing is now pretty much clean and trouble free. The web cam holster lets me keep an eye on things and the filament monitor sends me an email when the print is finished. All pretty ticketypoo down here in Oz!

NOT 40 x 40 x 38mm!!!

Actually 60 x 60 x 38mm thought I had the fan on the shelf..

Ooops, typo, Fixed

Thanks for a great design! I have started printing the parts, but have a request. Could you please load a version of the support posts STL file with the supports laying flat to the build platform? I can build them as is, but this would require supports.

Could someone share an image of where to mount the scrubber? Or is the scrubber not mounted to the machine? I'm not entirely sure how it would work if the scrubber is not mounted to the machine in order to suck/scrub the compromised air quality produced from the ABS. Is there a port cut into one of the windows of the Rep2X?

It sits inside the build chamber, in the back left corner. The air blows out a small cut-out in the corner.

I found a US vapor cartridge that nearly fits (http://www.amazon.com/gp/product/B000XUF7RI/ref=oh_details_o09_s01_i01?ie=UTF8&psc=1)http://www.amazon.com/gp/produ....
-- The R-621 is 68.9mm diameter inlet, 69.8mm diameter outlet,and 32.2mm thick.
-- I printed the thing scaled up 2% and it printed 70.5mm diameter outlet, 68.3mm diameter inlet, and 61.2mm square fan case. So everything fits but the cartridge inlet.
I don't have software to edit the diameters, so I'm going to do a small amount of dremel work and it should fit fine.

See http://www.thingiverse.com/thing:245644http://www.thingiverse.com/thi... for a middle fitting designed for . I had to use 103% to get the exhaust-side fitting to print at the right inner diameter. I used netfabb basic to slice up RodLaird's plate so I could print each component individually at different scaling factors.

Middle fitting for RodLaird's Rep2/2X Scrubber for use with Neiko Respirator Cartridge
by Jake

Performance update: with the corner plugs in the machine (see related Thing) and the draught covers suggested in that model, very little vapour leaks from the printer. I find that I can set the fan speed at a very low - and QUIET - speed and basically eliminate external stinks... The scrubber just stops vapour leaks through the induced negative pressure and keeps the machine interior fresh, so that when you open the printer you don't get a bolus of vapour ejected into your workspace.

I do suggest you take out the filter and shake it up from time to time to minimise the clumping of the activated carbon. Lower fan speeds / airflows will also significantly reduce clumping and generally also prolong filter life.

I'm going to fund our intern here at our school to adapt this to fix 3M's Tekk air mask filters. The shape of the 3M filters is not a circle as this design. Should take a week or two. 3M's air filter can be bought on Amazon.

Hello, was there an update on whether you finished making this mod?

Bravo - it will be a very popular mod! I think I offered to do this is
there was enough interest and in hindsight could/should have used a
globally available filter. However the filters I use are ever so convenient in form factor! (and are made by Scott - an international
firm - but I suspect to an Australian standard.) I have shipped some to
those who have asked - but this is not something I can/will do in

Bravo - it will be a very popular mod! I think I offered to do this is there was enough interest and in hindsight could/should have used a globally available filter. However the filters I use are every so convenient in form factor! (and are made by Scott - an international firm - but I suspect to an Australian standard.) I have shipped some to those who have asked - but this is not something I can/will do in future.

Do look at the new chassis corner plugs and suggestion to restrict rear hood airflows. These alone actually cut down a lot of emission and I would recommend doing them immediately while you are waiting for the scrubber mod. With the scrubber the performance is very good indeed. (with the usual caveats that nothing is perfect!)

Oops - somehow the reply got doubled; somehow editing one copied it to a "Guest" post... Huh? You get the gist I am sure

That would be great, thank you. I too am having trouble finding a US supplier for the filter.
thought about packing it with the round carbon filters. But the 3M solution would be the way to go.

Love the design and thinking about printing this. Can anyone recommend a vapour filter availabe in Europe (Germany), as the Protector RC-56 seems to be an Australia only product.

Sorry about that! I guess I should have picked a global product like 3M to design to... However, they are an awkward geometry. There are some circular filters made by Wilson, North, Moldex and others in the UK to which the design could be rapidly adapted. In truth an elastic band coupler could be made to work with any of these. The design files are there for you to modify. Let me know if you need another format.

Is there a way to mount this on the outside of an enclosure instead of the inside? Also about how long does the filter last before it needs to be replaced?

You could indeed mount the fan / filter assembly externally if you designed an appropriate air tube coupler. I built a prior external version that was noisy and ineffective and ugly/untidy. Coupling tube impedance is a significant problem. This design was the result of realising that a minimalist approach might be better in all ways. Indeed, this design;

  • tucks right out of the way clear of the HBP (is in fact visually unobtrusive)
  • much quieter
  • amazingly effective.
    indeed, printing all day today in an enclosed 55m^3 room resulted in barely discernible odour either in the room or case. And no significant excess noise. This is a huge contrast to the previous situation even when using exhaust fans and open windows. And where you could not avoid a face full of fug when opening the case...
    As for filter life; I cannot tell you for sure. Using this class of filter in respirators, I have always gotten several years use. So I'm guessing something of that order. The filters cost me around $5 so if I had to replace them frequently, I would not be bothered. Particularly since it is my long term health which is at stake - and at last I have a setup that I can use confidently with just normal room ventilation.

Can you push air through the filter instead of pulling it through like you have in your current design? I do like your design but I don't have a Rep 2/2x. I do have a custom enclosure that I was going to put a fan on and vent it out, but I have no place to vent it out to. Your design is a perfect for this but I have mount it on the outside of the enclosure.

I have uploaded the files for a blow-through-the-filter configuration to thing 125264. Let me know how you go. Good luck.

Rubber-band suspension does not work good in the long term. The bands will rapidly dry out, crack, and snap. Perhaps wrap some wire instead?

In this application I expect 3-5 years after which I will bear the enormous time and expense of putting in new elastic bands! I have neoprene bands that can also work, but their lower elastic reduces the noise isolation a little. I like the rubber bands better... If you are finicky you might want to source some silicone bands. Wire will not work in this design. If you find silicone bands let me know; I will not be bothering to source them myself for the reasons above.

Fair enough, but you may be having to replace the rubberbands yearly at least. I've tried using them to hold together projects, they do NOT cope well with... much of anything.

Stress levels are low on the little beggars; but if it proves they weaken prematurely then I also may drop back to the neoprene loops. While I have found some sources of more durable bands - they are only available in larger quantities. So seems I will stick to plan A. gain, let me know if you come up with another stratagem / source.

Performance update: Currently printing in a closed room to test performance. No odour detectable to my highly analytic vapour sensor (aka nose) with the final design. I would not take this as advice to work without good ventilation, but it does seem to indicate that this is working as well as you could hope...

A note to all who have downloaded this; my apologies but there are now new and much improved STL's available. There is a really simple exhaust system that pushes scrubbed air outside the case, ensuring laminar air flows and negative pressure inside the printer case. (And hides the motor wiring egress). It prints (like all my model components without support) and snaps together. You should also reprint the coupler and base because I have reversed the cartridge direction and this changes both of them. The old version will still work, but I suspect the airflow with the filter cartridge the right way around is a little better.... Sorry about that. The final design however works really, really well; aka its "nice"

I use an enclosed Replicator 1 with an increased size, high mass build plate. Because of this, it can get quite warm in the enclosure. I won't know until I try, but the heat MIGHT be an issue for the rubber band longevity. If this proves to be an issue I will look for an alternative method to bind it together. I'll share back if I do this.

The Rep2 / 2X's are all fully enclosed. You will not have a problem with rubber band deterioration; they get warm but not that warm!

Sorry to be dense but how does this attach to the printer/printer case?

Take a look at the last photo... It shows it on the case floor at the edge of the case. It is quite narrow so fits in very neatly with no clearance problems...

great reference as well, thank you!

I've been thinking about designing one of these for a while now. Thanks, now I don't have to!

LoL - my pleasure. Do let us know how it performs for you.