I am sensitive even to PLA Toxic fumes, and I need to have an enclosure for my MK4S
Hello,
last week I did another long print of about 6 hours, and guess what.... towards the evening I started to have a sore throat again. It felt like burning my mouth, and this lasted until the next day. Since it already happened to me several times, I'm now sure that I'm sensitive to fumes or particles from printing. Imagine that I was using simple PRUSAMENT PLA, nothing special. Imagine if I had used those awful smelling PLAs.
At this point I'm convinced that I need to use an enclosure on the MK4S. I looked at the PRUSA Enclosure but it costs almost as much as half a MK4S 😮 , so i decided to build one myself, and to start with I'll build an IKEA Enclosure which is quite simple.
However neither the IKEA enclosure nor the PRUSA Enclosure are airtight. I studied the PRUSA filter, and it simply filters the internal air, and re-introduces it inside (theoretically purified), but particles still pass through the myriad of spaced parts and surfaces that are not sealed.
Same thing for the IKEA Enclosure, whose Plexiglass is about 2 mm away from the wood. So I opted for the definitive solution: reuse the hole in my window glass where I connect the air conditioner in the summer, to connect an exhaust tube that will be connected to the IKEA enclosure.
The secret is that if I can keep the box under atmospheric pressure even for a fraction of a BAR this will prevent the fumes from coming out from the holes in the box and enter in the room, because all the air will be sucked in by the tube connected to the extractor.
To test the idea I built the crudest of enclosures: IKEA Lack as table, with the MK4S on top, with an IKEA stool (from which I removed the seat) on top of the Lack.
The stool is large as the Lack and so the MK4S can be fit inside. The bars of the stool legs act like the poles of a camping tent. I wrapped sheets of polyethylene made from garbage bags around the poles, all held in place with tape. A piece of cardboard with a circular hole on the back, supports a plastic jar cut in two, where the screw-on lid has been drilled and acts as a bolt to screw the jar/tube into the cardboard. On the front I put a transparent sheet of flexible PVC with magnets as a door.
I bought an adjustable PWM vacuum turbofan and two 10 cm diameter tubes on Amazon and connected everything to the jar/tube.
The concept works perfectly. It is enough just to keep it at speed 1 (with the motor that you can't even hear) and it already creates enough vacuum to not let out odours. I did a 7-hour print without the slightest odour.
Now that it passed the test, I moved on to rework on the CAD the parts of the IKEA Lack Enclosure and print them.
Work in progress.... 😀
Regards
An unfortunate condition. You are unlikely to be sensitive to fumes from pure PLA- unless you have problems with ordinary cooking; most likely you will be able to print natural, or clear PLA with minimum precautions while avoiding coloured filaments. PLA doesn't print well in most enclosures, especially in summer so consider printing in a closed room then ventilating the room for long enough for a couple of air changes before reoccupying it.
Cheerio,
RE: I am sensitive even to PLA Toxic fumes, and I need to have an enclosure for my MK4S
Hello,
unfortunately I can't. I live almost all the time in the same room, where I fit also the printers (MK3.5S+MMU3, MK4S, FLSUN V400) and I don't have other spaces. It would not be a good idea put the printers in the kitchen.. 😆
Now all the parts of my IKEA box are almost completed. I had to redesign almost all the plastic parts, because the original IKEA Enclosure from PRUSA was only 44 cm high, and the top cover is too low when the Nextruder is at the maximum height. Moreover the solidity of the upper plastic parts did not satisfied me: too much risk they could break during maintenance.
The new parts I designed do the following:
- They increase the internal space, bringing the heigh to around 54 cm, so that when the Nextruder is printing very high prints and it is almost at the limit, the filament does not turn and flex to 80° risking to break when the extruder is at X<100 or X>130.
- The lateral suspension wings of the plastic high parts should not sustain all the stress any more, since they are enforced with vertical metal screws.
Regarding the bed cable that hits the back panel when it is at home position, I do not plan to replace the heating bed cover with the 60° angled version, as the angled version converts the normal bend into torsional stress, reducing the life of the cable and increasing the possibility of cable breakage and sparking.
Since the box is only a square of 55 cm, there are two options I am evaluating now:
- Dismount the LCD and mount it externally, bring the printer forward and earning enough centimetres to avoid problems when the bed cable is all back.
- Cut a circular hole on the back of the Plexiglass panel (around 8 cm) in the cable zone and install a dome semi sphere just enough to incorporate the cable when it is back.
I will probably go for option 2, since the printer will remain unchanged.
Regarding the Power supply, I am evaluation also if I will move outside, since the continuos air replacement inside do not cause hot temperatures.
Keep in mind that this is the first Enclosure version, the one where all the cover part with doors and glasses can be just raised and removed way and it stays in place just by gravity
Regarding problem printing PLA: I am aware of the problem, here in my room on summer, I have around 32° C, so having a heating chamber can be an issue. However my Enclosure is all but a heating chamber. In facts, the box is under constant air depression, and there is a continuos air replacement, sucking air from inside the room and being expelled outside the house. Now, my room has almost 25° and inside the evaluation temporary box that is printing since 6 hours the PETG plastic parts with the bed set at 90° all the required parts for the box, the inside temperature do not exceed 32°C.
In addition I am waiting to receive my CORE One, so I will probably have the same issue. Once it will arrive I will have to modify to incorporate also to it the exhaust tubes. I do not plan to print ABS or PC on the MK4S with enclosure, I will print on the CORE One if the case.
Regards
RE:
For some design ideas, take a look at the assembly instructions for the Prusa enclosure. (I got one when I ordered my MK4 because there was a discount to bundle the enclosure with the printer.) Of note, look at how the Prusa enclosure handles the filament path. It uses reverse bowden with the fixed end close to the front opening of the enclosure. This helps manage the bending (and rubbing) of the filament on the underside of the top of the enclosure, especially at high print heights.
Another thing to consider about the design height of your enclosure. You may want to consider allowing extra enclosure height to allow room for a heavy paver stone (or scrap from a granite countertop shop) on top of a foam square (cut piece of yoga mat?) to act as a mass damper to cut down transmitting vibrations to the enclosure for noise control.
The negative pressure that you are planning is a good idea to keep fumes and particulate pollution from entering your living space. Just make sure that any place where air is intentionally allowed to enter the enclosure doesn't cause a cold air draft in the print volume. If you can't move a hole that is causing a draft, maybe a baffle on the inside right in front of the hole to disrupt the air stream.
See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs
RE: I am sensitive even to PLA Toxic fumes, and I need to have an enclosure for my MK4S
Good ideas. I did not noticed how PRUSA managed the filament in the original metal enclosure, I should check and keep note.
For the air entrance you raised an interesting point. Now even if the box is raw, all the plastic around block any air. But with the IKEA Lack, all borders around the Plexiglas walls and door have at least 3 mm air gap. Pro & Cons: they will allow much air to enter avoiding that inside the temperature raises too much and the power supply (that will stay inside), the electronics, and the LCD could not suffer. Moreover I hope it will avoid PLA to melt in the extruder cold area. On the contrary, air gaps could create cold fluxes that could bend sensitive materials; even if I do not plan to print ABS inside, in the past I experienced also bending of PLA and PETG of some manufacturers. I will see. May be I could use silicon glue to seal all the walls that do not need to be dismounted.
Regarding the damp heavy material, it will not be present since the IKEA Lack table on which the printer is, can't sustain heavy things (max 25 Kg).
It was planned to put the new arriving CORE One on a second Lack, but now I noticed that the CORE One weights 22.5 Kg, plus a 1Kg spool and stuff = around 24 Kg that is very near the maximum resistance of a Lack. Now I am not sure I will put on a IKEA Lack. I would avoid that with vibrations the Lack just collapse due to the weight to the limit. The legs are cardboards with top & bottom wood cubes to allow screws to be fitted. I will need a different table, and I do not have space now, since the V400 that is another beast take all the space on a solid table.
Even if I have almost finished to design the half sphere on the CAD I just found exactly the same thing on Amazon, in polycarbonate. Very nice and smooth, better that the look & feel it could have by printing it (and wait 11 hours); but it costs 17€ and it would improve a lot the final look. However it would require to drill 4 holes into the Plexiglas and in the polycarbonate without doing mess. I have not yet taken a decision.
Regards
RE: I am sensitive even to PLA Toxic fumes, and I need to have an enclosure for my MK4S
The Prusa enclosure is not airtight and has a lot of holes and such. Some people have even posted to Printables designs for plugs and things to make it more air tight. Prusa also sells a Hepa filter for the enclosure that recirculates the air inside the enclosure.