Is Vacuum Filament Drying Best the Best Technique?
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- เผยแพร่เมื่อ 12 ก.ค. 2019
- Baking filament to remove the moisture causes problems. It anneals PLA which leads to difficulty getting successful prints, and for the other filaments it causes hydrolysis which degrades your filament. By boiling the water out of your filament with a vacuum chamber you avoid both these problems.
RichRap's video about a low power heated filament box: • DIY Heated DryBox for ...
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This guy shows a scientific explanation for why such vacuum systems don't work as expected and don't give a significant result (th-cam.com/video/SfkphhQtEys/w-d-xo.html)
I learned a lot from this link. Thank you for posting it. Based on the new information I would say that a vacuum chamber is no better at drying anything than a chamber full of completely dry air (0% humidity). It now appears to me that the only advantage of a vacuum chamber for drying purposes is freeze-drying which really offers no advantages for filament drying.
@@DesignPrototypeTest actually is not the same. Pick up a basic of thermodynamics when you lower the pressure the phase diagram changes. You actually need a better vacuum pump please a diafram pump you are using an oil pump and breathing the oil gas you need to vent on the exit port using a hose.
At our lab in this situation submerge the petg or abs in ipa 90% to displace the water then a few hours later remove and plase under the vacuum chamber for a couple of hours ( turned on) and give it a try..
@@maxplank That's a lot of IPA. Then what do you do when the IPA becomes saturated with water?
@@RClarke3660 discard the ipa once you reach 80%ipa. You can calculate the water presence by the weight of the dry filament vs pervious weight and alcohol volume. Purifying the acohol(distillation) is not recomend unless you are licensed.
I'll give you some of my experience with vacuum and drying.
First up, try keeping your room dry with a room dehydrator. They aren't too expensive, and will take BUCKETS of water out of the room air per day. That's water that will never get into your filament to begin with. And it would allow longer run times without having the filament get wet.
Next, I would suggest you try chemical dehydration. There are a couple chemicals that will pull water right out of the air, and they aren't that expensive. One of them that works really well is used as an ice melt for sidewalks. I spilled a little of it on the floor of my garage and for years that spot looked like there was a leaky pipe above it. Finally I figured out what happened and cleaned it up. You can buy chemical dehydration systems made to keep closets dry. But they are pretty simple. Just a can filled about a third of the way up with the chemical, and it will fill up 2/3 of the can with water. If you enclose everything in a "Tupperware" type of box there will be a limit to how much water will end up in the can, because there just won't be anymore water left to pull out of the box. It keeps things VERY dry and is considerably cheaper than using a vacuum.
If you want to make your vacuum chamber work, try making a custom fit gasket from two part silicon mold putty from moldputty.com. It can pull such detail from a piece to be molded that it would seal the scratch on your window easily. Just mix the two parts, roll it into a ball, flatten the ball and reassemble the original parts on top of it very gently so you'll end up with about a 4 mm gasket. Then wait for your gasket to cure (about 10 min). Once it is fully cured you can tighten things down more.
Also, try a 2 stage vacuum pump. They work much better than the fan type pumps that were built to take Freon out of air conditioners and refrigerators. They pull a much deeper vacuum, which will cause water to boil a lot more vigorously. Trust me, I've had both, and once you go two stage you'll never go back!
One other thing. The "cloud" coming out of the output of your vacuum pump is a cloud of the silicon oil that you poured into it. Read the cautions on the label of the oil bottle and I think you'll agree that breathing it as an oil fog is probably not the best idea. It's best to vent it outside. But you certainly don't want to breath all the time.
Good luck. I hope some of this helps.
Pro tip from someone who worked around vacuum pumps for years: Stick a cut-off plastic bottle filled with cotton on top of the pump's exhaust. These pumps spew lots of oil mist!
P.S. There is no such thing as "negative pressure".
Sure, there is such a thing as "negative pressure". It all depends on where your reference is. The gauge that he got measures "gauge" pressure, not absolute pressure. Therefore, the reading that he will see on his gauge is referenced to his ambient atmospheric pressure.
@@Sembazuru sea level or ambient ?
@@Elamin008 Ambient. Disconnected from everything, that gauge should always read zero whether at sea level or on the top of a mountain.
You also lost vacuum to the water being removed from the filament as it boils out of the filament.
Rollie is correct. When you have moisture in liquid form and then boil/evaporate it, the liquid transforms into vapor. That liquid takes up approx 700 times the space than it did as liquid.
The best way to tell if the water in the vacuum chamber is the cause of your pressure increase vs an actual leak wold be to first clean and dry the chamber with paper towels. Then vacuum the air out of the empty pot. Leave it sit overnight. If the pressure holds then you have a good pot without a leak and the pressure increase is your fillement drying out as intended.
As every AC guy knows. The System which has swallowed water is only dry again if the vacuum stays min 24hrs. Otherwise evacuate again and again. ..
I use the same setup and I don't lose that much in such a short time. It holds vacuum very nicely for days. ABS does not hold as much moisture as Nylon does (up to 20% volume) and I still don't get a noticeable drop in vacuum over 12 hours or more.
Those pumps are meant to run for extended periods. They will get hot but that's normal. You are constantly losing vacuum from water boiling out. Leave it running for an hour or two to boil the majority of water and then let it sit in the vacuum and pull down again if necessary
Can confirm this. You'll see the water vapor coming out of the pumps exhaust while it's boiling off as well.
@@dayjeremyThats oil..
This is the type of video you are great at. You got the discussion going and then experts filled in some of the missing data. In HVAC, you have to leave the vacuum on until closing the system sees very little rise (water vapor). You were very nearly there. Well done. Make more videos like this.
Cool idea. As a 30 yr. veteran of the injection molding industry, I would say that you would be better of using ceramic sieve desiccant. Nylon needs to get warm enough to open the pores and release the water molecules. Usually around 170 deg F ish. You will need to regen the desiccant in your oven but still doable. Check molding suppliers like ppe.com to get the desiccant plus a bunch of other plastics specific items.
Awesome information. Thank you!
@@DesignPrototypeTest, you might get much better results if you gently heat the vacuum chamber to like 90+F / 30+C. This will speed up the process considerably. Also, over Ebay you might find much better vacuum chambers with glass lids.
Consider using a little silicone or teflon grease to improve the seal.
Another word of advice: never try to cold-boil water on a rotary vane vacuum pump such as yours. The water vapor will inevitably condense inside the pump vanes, mix into the oil and damage your pump.
You're correctly turning on the pump and then close the valve, this will prevent the water from migrating to the pump. I suggest you drop a few silica drying bags into the vacuum chamber, that will trap any excess water that could be migrating into the pump once you do the vacuum.
That's it for now.
Try using some 3M vacuum grease on the seals. This should help but, as stated in many posts below, as the water boils out the vacuum will drop and that is a good sign that system is doing the job. Great vid!
the drying will slow down over time as the filament gets colder over time and thus there is less energy to make the water boil. Thunderfoot explains some of this in his video about a fake vacuum dryer. So adding a heat source will increase the effectiveness of the filament dryer.
Make sure to run the vacuum pump till the oil gets hot as water gets in the oil from the air, the heat forces the water out of the oil, but if its on till it heats, on and off quickly it can be a issue. Cool video 👍
This is probably one of your best videos. A simpler solution to keeping a vacuum in the chamber would be to simply use a timer. Not quite as elegant but probably just as effective. You really don't have to worry about overheating the vacuum pump. I leave my harbor freight one on constantly overnight when evacuating car AC systems. One of the things you may not have considered is that the increase in pressure inside the chamber, or decrease in vacuum, is that the water vapor from the filament is whats doing it. There may also be offgassing from the plastic itself. It might not be leaking. So yeah, a timer set to turn on the vacuum pump once an hour for 2 minutes or so, would probably do the trick. Setup a solenoid valve to open and close on a delay-opening just after the pump starts and closing just after the pump stops. Sounds like a cool little arduino project. Perhaps a simple check valve could contain the vacuum inside when the pump turns off...thats even simpler if you can get a good enough check valve and one thats sensitive enough
Thanks for the compliment and great ideas!
I have no experience about drying filament but I got experinece about industrial dryer for plastic material, The "filament dryier" can be considered as "hot air dryer", while resins like PC, PET, PA ( also compounded with filler such as wood powder) usually requre dryers. There are many kind of technology but the most common about dryer use the technology of molecular sieves, In short the difference is about the quality of air you flow inside the chamber where the resin is processed. Molecular sieves dryer can acheve very low moisture inside airflow so the resin is forced to loose moisture. Others effects than hydrolysis can stress the resin, there are also oxidation and thermal stress (PET suffer a lot about hydrolysis during thermoplastic process, like PA but PC suffer about therma stress. For that reason there are some "recipe" where is listed: the process temperature, the residence time and the level of dreyed air required to achive a deifned drying process. Usually there must be defined the final moisture (measure in ppm) and the initial one so Winston Smith is in true: raw data of moisutre contnenet can be measured with thermobalance or other analytical equipment but they aren't cheap. You can run one test, warm one spool with the owen till you got the full temperature, than run with the vacuum, you'll get beeter result than run only with vacuum.
I suspect you've already figured this out, but the reason you're loosing vacuum is the remaining moisture. Look up rate of rise once you clear that bar you know material is dry. I worked in high vacuum industry (cryopumps and the like) for some time otherwise I'd not know this unusual phenomenon.
The way those four spools fit perfectly in the pot...
I worked in the semiconductor manufacturing field for many years where achieving and maintaining high vacuum is an art as much as scientific. This particular application would be considered "rough" or low vacuum. Wish I would have kept one of the small 2-stage 15cfm mechanical vacuum pumps I used to deal with on a daily basis. Would have been handy now that I need one for drying my filaments. BTW, your vacuum chamber won't maintain a vacuum for very long because the sealing surfaces are too rough to make an idea seal plus the the filament and spool will constantly be out-gassing for quite a while. Also, any finger prints either on the spools or on any inside surface for the chamber will also out-gas for quite awhile. You would have to have that 3cfm vacuum pump attached and running for several hours to get rid of most of the water vapor and other contaminants. The problem with that is that pump doesn't have a oil mist filter on it's exhaust so it'll get a bit smelly in the room.
You are absolutely correct, Im using a 7cfm Vacuum pump and let it run for 90 minutes, works well ,
The idea of the vacuum switch is great, however you cannot leave the valve to the vacuum pump open when the pump is off.. If you do so, it will lose vacuum. So you would need a vacuum switch and a solenoid with a delay on make relay to allow the pump to start and run for a minute or so to bring a vacuum on the hose before you open to the pot. A micron gauge will be more accurate and your can take the reading of that gauge and see the boiling point of water at that given vacuum level.
Why not just use a check valve?
@@Bantallar I don't know of a check valve that is deep vacuum rated. I'm sure there must be one. I come from a HVAC background so that is the knowledge I have about boiling water out of AC lines when performing a repair.
Do you have a digital scale? They're cheap. It would be interesting to weight the spools before and after each vacuum treatment.
There will be only a small difference in weight, unless you’ve kept your filament out in the rain for a week.
The drop in vacuum could be attributed to gas accumulation in the tank as the water changes phase.
Yes, it's a frustrating business, but it's always good when we end up with the same number of fingers. 😁
I've found PET-G a right mare but the layer adhesion and stability are too good to pass up. The initial chinese filament blobbed terribly, so I switched to a Dutch filament. Straight out the packaging, exactly same result. Sooner or later a blob ends up kicking the X or Y stepper out of line. The problem seems to have two main causes - overhangs, and infill. I can design out the worst kind of overhangs by rounding corners, but the infill has the habit of causing the bead to lift up behind the nozzle. PLA is incredibly annoying because it prints so beautifully, but just doesn't have the properties I want. ASA seems pretty good too, and I use it for parts subject to weather and UV, and when I want to use glue. But I'm still keen on PET-G for some parts. I've been trying to fit a piece of PTFE around the tip as a kind of wiper blade, but PTFE is crazy stuff to work with. I fitted the nozzle through some aluminium in the hope of searing a piece into place, but again no luck. I got the threaded end of the nozzle glowing red at one point and melted the aluminium, but the PTFE just fell off. I swear it was sneering at me. Then I carefully polished the brass nozzle to a real shine and wiped a cotton bud round the sides with a bit of silicone release agent. Even in my advanced state of aggravation, the result was really quite hilarious. Printing a plain cube, instead of the usual crosshatch of infill, there was not a single line inside the whole thing. I ended up with perfectly formed pillars from the bottom to the top and nothing connecting one with another, not even stringing. Now I've got to get rid of the silicone, which is a science in itself. But the good news is it's mostly gone and I am now nearly back to where I started. Meantime, after a five day run of ASA printing, my eyes, nose and throat are suggesting to me if I don't get some ventilation I might not need to worry about anything much longer anyway.
This is gold.
@@DesignPrototypeTest Gee thanks, Matt. I'm honoured. 😊
You still need to add silica gel or calcium chloride to the chamber to scavenge the water vapor released, as well as periodically running the pump.
Get another lid from the supplier - that scratch is unacceptable as it is a stress riser and could cause an implosion.
Phenomenal. I was just in the process of designing a similar device! Awesome work! YES, TPU is like popcorn when moisture is high! Molecular sieve is a better agent. Also use a proper vacuum type hose.
You got a great deal on the chamber, I can’t find a similar sized unit for that sort of price here in the UK...
Great video man. I’m all for R and D and showing your workings. The ending was mind bending back ground music wise. You do need to keep an eye on it, too be on the cheap. 👊🏻🇦🇺🍀😎
Heat does do the trick. I set my heating pad to 5 degrees C below whatever you set your printers heated bed to, to print a particular material. So when I have a PLA spool on the bottom of the chamber, I set the heating pad to 55 C. I lose about 5 C through the bottom metal surface and the silicon liner, so the PLA spool get about 50 C. If you want to dry PLA and PETG at the same time, I’ll put PETG on the bottom, set the heat to 80 C, and stack other PLA or PETG on top, up to 4 total. Put the hygrometer on the top spool. Pre-heat the chamber for 1hr before turning on the vacuum. The duty cycle of pump isn’t great, so I don’t run the pump for more than an hour before giving it a rest to cool down. While it’s cooling down, the heat is still doing it’s work.
Hey! Add cheap mechanical timer switch to the pump to turn it on for 15 minutes every 2 hours. That should keep nice vacuum. You can also easy program it to not operate during night hours for silence.
man this is the videos i was talking about no bull crap just straight up cheap ways to do stuff man keep this stuff up!!! and your right about the spools i’ve seen that the spools count in some of those super cheaper brands
Hi very interesting. Nearly 60 years ago as an apprentice we used grease smeared on the sealing surfaces, seals and the metal rim etc. We used needle valves for control. If the leak is consitant you could use a timer to switch the pump on for short periods at regular intervals.
yea I went to a secondhand store and got a old pressure canner did that a few years ago works great still works today
Wouldn't you have to keep pulling vacuum to fully pull the water out since when you stop the boiling stops?
Indeed
Simple/cheap pressure switches are not accurate enough to trigger at low pressures. A cheap vacuum switch could be made from an absolute pressure transducer (sensor), an inexpensive microprocessor like an arduino and a solid state relay. There would be a little more to it than that, but it would be about $20 or less in parts.
Although a vacuum chamber probably isn't the best way to go. What you really need to do is to find some way to reduce the partial pressure of water vapor in the air around your filament. You can do this with a good desiccant or some other dehydrating system that works at atmospheric pressure and room temperature.
You can usually keep the vacuum pump running, they are more efficient when pumping on nothing, no work done so much less heating. Also the water will probably leave pores in the filament. The air will expand when heated and might still cause popping.
Freeze-Dried Filament! I think you might be on to something....As usual, love the process you go through.
that heated box you were talking about with heated mat, maybe the mat was a seed starting mat, is placed under seed trays to help warm the soil.
I'm checking out 3D printing and came across your video, I don't know how big the spools are but you should be able to 3D print support rings/baffles to go inside the 5 gal bucket to keep it from buckling in on itself. maybe 5-6 rings spaced out in the bucket ,as long as the spools fit past them!! just my 2 cents..
Fantastic idear :-)
Nice to see the real test/trial process, love it :-)
When you lowering the pressore on air/water, then the boiling temperature of the water is lowered, that is why it i boiling at room temperature.
CNCkitchen (Stefan) says, that when baking PLA, you may not exceed 40oC in the oven.
Nice walk through
Thanks for sharing :-)
Ex commercial diver here that had to be pressed down in a decompression chamber multiple times after many saturation dives. Even though it is the opposite of what you’re doing they are pressuring us down to dive depth And then slowly bringing us out according to the step plan it is a essentially a vacuum chamber in action. When we are being pressed down to depth or pressurized It is equal to you bleeding gas back in to your chamber bringing it back to atmospheric pressure. The issue is when we would get pressed down There would be massive amounts of moisture caused by this in the air and all over the walls of the chambers so I would think you would Negate any drying done by the vacuum by moisture induced when you bring it back to atmospheric pressure.
Great video! A suggestion: Try drying the wet filament by leaving the vacuum pump on for the duration of the drying period. That way the vacuum level stays constant. You probably will dry the rolls in a couple of hours. Yes it is annoying having the pump on but you can put the system in a closet or room or build a sound barrier. The exhaust is most likely the low molecular weight vacuum oil in the pump which should dissipate after time. You can put a exhaust filter to reduce that issue.
I like the suggestion to add desiccant, so you know where the water has gone too. Good work on the video.
I think that you only need to store your filament in a warm place in your house (I store mine in the same cabinet where my water heater from 1965 resides) this will keep the air moisture well below the rest of the house and ensure that the filament will have no moisture to suck up. When printing you should keep the currently used filament in a tight dry box with desiccant to minimize the amount of amount of moisture that gets access to the filament. A bowden tube from the dry box seems also like a good idea.
Great ideas here. I've got another suggestion you could try on the cheap. Copper sulfate is a farming chemical used in soil and looks like blue rock salt. When you bake it, it dehydrates turning white and wants to absorb water a lot.
If you make a batch of anhydrous copper sulphate and put a bunch is the dog food pail, it should pull out moisture and maintain the spools dry. I haven't tried it, but if you got the other stuff already, maybe it will work for you.
Good job dropping the filament.
I've not once ever had an underweight spool. I was curious about weights myself when I first started 3D printing and found the opposite - weighing spools before use and after use showed that suppliers usually diddle themselves out of 20-50g of filament.
If you're getting short changed on filament maybe you should change suppliers.
I picked up several pressure cookers dirt cheap from second hand stores. I pull down to -20 and leave for 24 hours prior to print.
Great video. Very interesting. I love to see new ideas coming to life like this. Maybe you could make a thicker gasket to seal the chamber. Perhaps one that could clamp the lid down as well. A 2 part epoxy might help with the crack, or contact the seller and get a new one.
Either way can't wait to see what you do next. Keep up the good work.
Great video best 3D printing news and info keep it coming love it 😊
I will endeavor to heed your advice. Thank you for the compliment. 😃
Very nice exploration! I just got my food dehydrator setup working not long ago and it works pretty well. But now I see a solution like this and I feel like I need to migrate over to that... Maybe one day when I have the money and a ton of printers lol. Nice video.
I feel like you could make basically what you bought. Harbor Freight sells a stainless pot that looks almost identical to that. You could use that with the King of Random vacuum chamber.
Some pumps can achieve a vacuum lower than the vapor pressure of the pump oil. When that happens, the pump oil vapor can stream out in to the vacuum chamber and leave oil residue on everything.
It's better to find a pressure above that point, and use a PID controller to maintain it, then get a small heater like a "Golden Rod" to do the bake out.
NPT electric feed-throughs are not hard to find and pretty easy to seal.
Could you test the this and food dehydrator side by side? I would like to see a comparison by the hour of the quality of the prints. The downside of the dehydrator is the electricity it uses and the time it takes, but maybe it it produces higher quality in less time compared to the freeze drier. I dont know, but thats why you should test it!
I have one question! If you use a vaccumsealer like when you put food in a bag and suck out all the air from the bag, would that be a good filament drying method?? Maby something you can try out in your channel? Maby even try to throw in a "silica gel" bag in with the filement before you vaccum the bag, like when you buy the filement from the store?
I've never had a spool of filament that included the spool's weight to the advertised filament weight. A '1 kg spool' holds 1kg of filament and weighs a total of (usually 1.25 kg. 0.25 kg for the spool.
If you need a quick easy way to dry your filament.....
Most 3d printers come with a heatable printing surface.
Set your print bed temp to 50 degrees. Place your filament spool on the heated bed.
Put the cardboard box your filament came in over top of your spool.
Wait 4-5 hours.
Ta dah!!!!!
THIS IS GOLD!!! Did you come up with this idea? Where did you see it posted. I need to give credit.
@@DesignPrototypeTest My idea I guess.
I havn't seen it anywhere else.
I thought about it awhile back and gave it a try on my Ender 3 pro. I wasn't sure if the heated bed would time out but it stayed on overnight at 55 degrees.
I used it on a stubborn roll of carbon fiber PLA. It seemed to help.
I am sure someone could fancy it up a bit with a store bought plastic cover and I also put a couple of silica bags that came with my PLA in there as well.
Feel free to spread the word.
Cheers, and happy printing.
nice work, I was also just about to suggest add a strong desiccant into the chamber, something like calcium chloride is very cheap.
Alternatively, you could attach a second chamber specifically to hold the desiccant material, which you would use to dry the vacuum. It would need more valves, but by detaching the desiccant chamber, you would be able to remove and replace the saturated desiccant on the fly without having to lose the vacuum in the main pot completely. As @strwlf3 suggests, you might even be able to create a drying chamber that doesn't require a vacuum, just a warm desiccant (or perhaps as an adjunct to your filament dryer as well).
Everyone mentioning the lose of vaccum do to the water is correct. As the water turns to vapor the positive pressure generated lowers the vacuum in the chamber. Same vacuum principle is used to evacuate moisture from air conditioning and refrigeration systems. You just have to keep applying more vacuum as the chamber loses it, and you will know there is no more water when the vacuum stays steady without having to apply more vacuum.
You would probably have better results if you left the vacuum pump running continuously. That pump was made for evacuating air and moisture from AC systems. As a rule of thumb, we would draw down an AC system for at least an hour.
How would you compare the vacuum method to a food dehydrator?
Great video, please keep experimenting with this method, the vacuum need to be kept for better drying. I think. Btw, how about an acrylic chamber, made in cube form?
One other thought. You could use a prototyping board (Raspberry Pi, etc.) with a camera and some OpenCV magic to turn the pump on whenever the dial drops to a certain level. Just keep the camera pointed at the dial and let the Ever Watchful Eye decide when to kick on a and off a solenoid switch connected to the pump.
“alex schubert” I have a water separator attached to the pump side of the vacuum hose to keep water out of the oil. Should I not have that there?
I think you can easily improve the effect significantly. Water at room temperature needs less than 30 mbar to cook. In addition, you have to pump out the evaporated water. I think you need to run the punp much more often. Maybe something like all 5-10 minutes for a minute.
Have you thought about using a wall plug programmer for the pump ? Maybe a 5minuts run every hour is enough to keep the vacuum
How would desiccant work in a sealed container with the filament? Desiccant packs are cheap and might be a non-powered solution.
Not sure how accurate you could make it but you could use an Arduino with and LDR and a relay. Detect the black needle on the gauge and when it drops the needle, it'll be a higher signal with more light getting back to it.
You could possibly even design a part that clips the LDR to the gauge and be rotatable so you can make adjustments.
The pressure increases in your vacuum chamber because of the water leaving the filament. You need to keep the pump running while vacuuming it to continue to pull the water from your filament. Also, you should dry your filament in a food dehydrator and then while it's still warm vacuum the water out. It'll be much more effective. A food dehydrator can't dry filament effectively if the ambient relative humidity is high. I 3d print a lot for my business and much of that is TPU which absorbs moisture quickly. A food dehydrator can't get my filament dry enough for good prints even at 80C for days. Putting the warm roll of filament into my vacuum chamber for a couple of hours (as the pump runs the entire time) does get my filament perfectly dry. Maybe someone will read this and decide to try vacuuming their filament to dry it the proper way.
I am thinking an old pressure cooker from thrift store converted to vacuum pot has positive lock and seal
When working with pressure differentials I always run some math. Your ~4 inch wide by ~20 inch tall wood panels would equate to:
4 x 20 = 80 square inches of surface area. The differential pressure seen across that panel would be the vacuum pressure ~30 psi (pounds per square inch).
80sqin x 30pounds/sqin = 2,400lbs of force against each single face of the wood box. That's 9.6 tons of atmosphere going for a big crush. I'm relieved that plan derailed before completion.
Maybe try several 1h cycles next time with time in between to let the water in the filament warm up again for the next cycle. As pointed out already, the evaporating water lowers the vacuum. Also, an infrared heater may work if you want to go continuous, however that may also melt the filament.
I have a good high quality vacuum sealer for food. When sealed, the bags keep air out seemingly indefinitely. How do you think that would work for keeping filament dry??
Stick a desiccant pack inside the package and I think it will work fantastically.
If dry filament is better then why does my old filament print better when I submerge it into boiling water? I live in a very dry climate and believe that my old filament deviated from it's new idea moisture level as is over dries. You know new filament is passed through water to cool right?
is the spool weight included in the price of the filament? isn't the filament spool a measured weight? the filament is 1kg regardless of packaging weight.
King of Random has a few videos on how to create your own vacuum pot. Their method with a custom gasket could provide a better seal.
Make a clamp that goes over the lid and mounts on the handles. You need some force holding the seal besides just vacuum or it may be the scratch as well.
Just had a idea, how about using a room dehumidifier and dry everything in the room all the time, even when the spool is on the printer.
Similar to my vacuum bagging device ... I would suggest to also install a vacuum switch that will shut the unit down when it reaches the desired vacuum. Later
You could use a pressure cooker for your pressure vessel (vaccuum chamber). Seems like it would be straightforward to swap fittings with existing holes in the lid, dont forget to get rid of that pesky pressure failsafe if you're doing this though. Cheap pressure cookers should be available almost everywhere.
I know I spelled vacuum wrong. Vaccum. Vacumm. What ever. “Misplaced prepper1”, I do keep the vacuum pump running as long as I’m home to mind it. If I leave, I turn off the pump but keep the heat on. I keep one of those cheap button type hygrometers in the tank so I can see the RH level. I’ll run the pump for an hour with heat, turn off the pump and wait a few minutes to see if the RH rises above 10%. If it does, I turn the pump on for a little longer. I do that until the hygrometer stays at 10%.
The vacuum is exhausting oil mist. Some brands (and 3rd party suppliers) have mist filters for the exhaust to reduce the oil loss and contamination of your workspace.
Part of your vacuum loss is due to water boiling off, but also because your chamber is not designed to hold vacuum for longer than about 10 minutes. Your solution to use a vacuum pressure switch or an Arduino with a pressure sensor and relays should compensate for the system leaks.
The large Tupperware container with a seed starting mat or a reptile tank heating mat is an interesting idea.
when you pull a vacuum, as the water boils out, you lose vacuum. The vacuum is being replaced by water vapor. When the vacuum stops going down, you know you have pulled everything out that will come out. Suck it down empty and see if it holds. If it does, it's working exactly like it should.
Lone Wolf I’m a little late to the game here, but they missed the whole reason we don’t use vacuum to dry our cloths or dishes. The amount of heat lost when the water evaporates is hard to overcome. Then the temperature drops below the point it will evaporate under those conditions(plus the loss of vacuum due to the evaporation. Vacuum pumps are designed to keep running so It can evacuate the humidity and overcome the vacuum loss.
For "hot drying" PLA you need to keep below the Tg (glass transition temperature) 60-65 C.
Filament could be used inside the vacuum sealed package, all you would need is a a box frame to let the spool rotate.
feed output through a silicone valve. It may not hold a vacuum after opening, but it would limit the amount of moisture.
I was just doing a bit of investigation .... were is the water going. From what I’ve read the water is accumulating in the oil. The oil needs to be replaced when that happens or it will damage the pump. Vacuum switch has a range on the cheaper ones. Adjustable gets up there all available on Amazon. Thanks.
Why not try using a 1 bar (relative) pressure switch inside the chamber and reference the atmosphere (through a port)? If the switch is inside the chamber then the ambient pressure should activate it when the pressure is down around -1bar. If you can’t find a normally closed switch, just use a cheap relay.
Ideally you need to give the water a place to go. I put silica gel dessicant beads in the chamber with the filament, then evacuate it and leave it until I need to use it next.
Scotch brite and high vacuum grease are your friend.
Non vacuum rated valves are going to give you non stop troubles.
Building one of these currently for same reason.
A cheaper, slower solution might be to store your filament with a chemical desiccant, in which case you would need only those dog food lids and plastic pails. Silica gel, calcium chloride, even oven dried wood, many options.
Another cheap possibility is to attach a simple household timer to the vacuum pump such that it runs for a few minutes each hour, regardless the pressure.
You need a 2 stage vacuum pump to get a true vacuum. You need to pump that thing down to 29.92" Hg or - 1 bar to get a true absolute vacuum.
1. A bit of drying agent like silica gel in the chamber.
2. A timer turning the pump on for say 30 seconds every 2 hours.
That pump (Zeny) is now $65.99. I know this the food dehydrator trick does not work for me even after 3 days I still get steam and pops from ABS/PETG.
what was wrong with that print with the wet filament? All my prints look like that!!
i know this was awhile ago but i thought you could have used some metal rings on the inside to stop the bucket from caving in on itself
A 20 dollar pressure cooker modified to hold vacuum plus a $15 hot plate would have solved everything. I’ve been doing like this with a two stage vacuum pump for years. You just can’t overcome the evaporation lowering the temperature and stopping the evaporation without a little heat. I don’t even worry about my filament getting wet anymore cause I know I can dry in in an hour or less. I adjust the hot plate so the pressure cooker is never over 120 deg and keep an eye on it.
What program is that he used to design the model?
th-cam.com/video/pKLSTQcFTUI/w-d-xo.html
Design Prototype Buy ! , best shoping review chanel ever!, btw you print then you aneal it not the other way around xD
You've almost built yourself a vacuum oven. All you needed to do was heat your chamber and leave the vacuum pump running. I'm surprised you didn't test this.
Take an old boiler, and cut out of it a metal tank, or an old large pot, cheaply and securely.
For keeping the vacuum try a cheap wifi power switch and a webcam pointed right at the gauge. It cant be that hard to have software detect if the needle is within range, and if not to turn on the switch till it is. (I'm sure this could be achieved with a $10 ESP32Cam, and maybe a switching mosfet)
If you want to collaborate on such a thing, drop me a line.
Boiling does not equate to evaporation. The better print equality you experienced will be due to a small amount of drying whilst in a zero humidity and due to you exposing 'fresher' filament as the spool unwound. Think of a cylinder shaped packet of biscuits/cookies that's been left open at one end. The first one is soft/stale but the further into the packet you go the 'fresher' they get.
Cheap stainless pot, a plexi lid and a gasket is about all you need. However you are not going to "freeze dry" using one of these. Freeze drying is alittle bit more complicated then just tossing it into a vac chamber.
Cool video! Glad I moved to Arizona! Lol. Do you watch AvE?
Yes, of course I watch AvE (Arduino versus evil). Long live the empire of dirt! Lately his channel is more CNC related so I'm not watching as much as I used to.
Design Prototype Test yeah me either! I love that guy!
Design Prototype Test I find the Cnc interesting, but I don’t have a cnc, sooo...
I still got moisture into my pla moisture gets into everything F moisture, I ordered some roles of petg that were vacuumed sealed and guess what, that had bloody moisture in it as well, not buying from that supplier again
New subscriber here... 🤜🏼🤛🏼🇦🇺😎 The wood version should be tested too it’s fullest and beyond as a safety video🤓😂 Vacuums are powerful beyond belief. The fact we all are existing within one right now doesn’t make vacuums safe.... there’s irony there somewhere😐. Wood splinters give high velocity... splinters equal fast aerodynamic projectiles. 😏