Strong 3D prints through ANNEALING, but... Part 1: PLA

[@xyzconceptsYT]

I have done anealing of PLA, I tried a 3D benchy. The layers fused so well, there were no layer lines to the naked eye. The Benchy was now a perfect PLA puddle.

[@CNCKitchen]

Congratulations 😉

[@GridDweller77]

You had us in the first half, not gonna lie

[@mururoa7024]

You just melted the surface. Cut it open and you'll see the layers are still there. There's no way FDM can compete with injection molding unless you're ready to shed $800K for an industrial printer from say Siemens or HP.

[@xyzconceptsYT]

@@mururoa7024 The PLA puddle means annealing went horribly wrong. I made no claim or comparing that it was like "injection moulding" at all.

[@mb2k100]

@@mururoa7024 R/woooosh

[@feliperodrigues2487]

Hi Sthephan! I was able to get a +300% increase in impact resistance while annealing natural PLA. I tested according to ASTM D4508, for which the sample is smaller. As printed, it broke easily, but after 20min at 95°C they did not even break, using the same pendulum. I will be publishing the results next year at the Brazilian Congress of Manufacturing Engineering (COBEF2023).

[@CuttinInIdaho]

are the results available?

[@SpunkyGo0se]

link the results plz

[@AutoRevLife]

Was there any warping?

[@waynefilkins8394]

have you tried petg?

[@00-Dima]

So where

[@HitsandHeadlines]

Stephan, you are a godsend for the 3d printing community. Thank you for your service

[@CNCKitchen]

At your service 😉

[@capmilk]

Don't listen to Skynet! They will be printing Terminators soon!

[@HitsandHeadlines]

@@capmilk 😈😈😈

[@subtilo3322]

Couldn't agree more. Greetings from Belgium.

[@MisterMakerNL]

I finally get your you-tube channel name.

[@court2379]

But what does his wife say about hijacking the oven?

[@jaynayk1176]

Court when the print is thin it might I don’t know work with the heatet bet

[@AnsAnsAns]

I don't

[@moleyfromsmokelawn6902]

@@AnsAnsAns cnc KITCHEN. he uses a kitchen appliance in the video 🤙🏻

[@iandawkins2182]

I love what you are doing, taking 3D printer to the next level and breaking new ground and dispelling urban myths on 3D printed parts. Thanks and respect.

[@CNCKitchen]

You're welcome!

[@gianfrancolozupone3271]

I have tried boiling some PLA+ parts (kind of ring shaped) and letting them cool down to 40c in the water. They were thin walled parts, 2mm thick, so 10 minutes boiling was more than enough to change the temperature resistance. As a result the part was still hard at 80c while normal PLA gets rubbery at 50/55. But the same results with deformation and warping. Uneven depending on the axis. I will keep trying with other shapes and failed prints just for fun. I still think that this can be useful in parts that can be printed, annealed and then post proccesed to get the desired dimensions (sanding, drilling, etc. ). Great channel!! I really apreciate your work. Congrats!!

[@CyanOgilvie]

I've annealed PLA (plain and modified) by dunking the prints into boiling water for 5 minutes, then quenching with cold water (not my original idea, saw it in a youtube vid somewhere). I mainly do it for the improved temperature resistance, but that is almost always with functional, mechanical parts that need to fit with other parts, so warping is not acceptable. I've found the boiling water method produces almost no warping at all, other than the predictable shrinkage in x and y, and growth in z. The shrinkage is predictable enough to compensate for in the slicer. I've printed a fan duct that works fine on the MK2S, a few mm from the heaterblock, printing high temperature materials, so the heat resistance is good with this approach. It's also way quicker and easier than annealing in an oven. My process is to put the part into a mug or similar and pour boiling water over it, tumble the part to get rid of trapped air bubbles, then pour in cold water after 5 minutes. Once the part dries it's ready to use.

[@ZILLION4EVER]

reacting to your question on 2:20: yes, used volcano pla (formfutura, crimps minimal, reasonnably cheap as I live in Belgium, for usa the shipping must be crazy) like you used on that coffee maker like a year ago (?) printed clotheshangers from that and they are holding up after one year of serious (ab)use : one time I noticed visitors put like 3 wet winter jackets (heavy!) on one hook and it didn't fail. Used your 'making parts stronger info' vid and did print them with 5 perimeters instead of high infill. clearly worked, thanx for all the research Stephan!!

[@ElectricalInsanity]

I wonder if using a heated build chamber would make a difference in layer adhesion?

[@Slavko_Husam]

good question, I would like to know the answer too

[@faxxzc]

Yes it does. i get up to 100% adhesion in the Z compared to the xy

[@Anon.G]

Yeah it does, same with lowering the fan speed

[@MrHeHim]

Keeping the print warm definitely helps with layer adhesion, same with slower printing speed (really slow) and slower cooling fan or just turned off. Which has me investigating how to turn off the cooling fan for internal fill, so that the fan only turns on for the shell. Furthermore, so the fan only turns on at a certain level of degree and ceiling layers. So that when you print vertical walls there's no cooling fan, but once you reach let's say 75 degrees it starts to kick in or ramp up for the outer shell if its printing outwards or the inner layer if its printing inwards. Might have to write my own code, haven't done that in a while lol.

@@MrHeHim you don't need the fan for pla but it does help with bridging and you should be able to enable it just for bridging easy enough.

[@gannacss78]

Hi! I looked a bit into that subject previously to improve my quadcopter strength. I found that if I disabled cooling and tweeked a bit the temperatures the parts were almost not deformed after the heat treatment. Of course, disabling cooling and the temperatures affect the look and it is not suitable for all parts but if you are only looking for strength it is good and you do not need to compensate for any deformation. Thanks for the work you do. It is quite interesting and helping. :-)

[@jonwebb9261]

As always, this video was incredibly informative and all the testing was very detailed. You really are an asset to the 3D printing community and I've seen no other channel go into detail in the way you do. Great job man

I'd like to see you test the hook that completely melted and see how it fails compared to the normal vertical hook. Great video always enjoy them thanks.

[@dbaznr]

There are different results changing the infill density. 10%, 50% and 99% behave differently, especially regarding the type of deformation (uniform in X and Y). Z shrinks less, meaning that there is not a big layer fusion. Also, the deformation depends of the infill pattern used. A ventilated oven usually distributes the temperature more evenly. I'm not sure of the benefits of the slowdown temperature because in any case the skin remane cooler than the interior, and the process of loosing energy depends mostly from the geometry of the part, creating deformations. I'm testing the results using the microwave oven...

[@RentableSocks]

please try this with Esun PLA+ , in my experience it performs better than standard PLA when annealing.

[@iandawkins2182]

I use eSun filament as it is a great affordable filament. Have also had some great results with Hobby King own brand filament too.

[@boggisthecat]

Ian Dawkins The more expensive HobbyKing stuff is made by MCPP: www.mcpp-3dp.com The engineering PLA - ‘PLA-X3’ - is very good but a little pricey. It has very good annealing behaviour.

[@iandawkins2182]

Thanks that is useful information.

[@andylindsaytunes]

You should have called this episode "Make 'em, Bake 'em, and Break 'em."

[@nict2618]

I recently tried drilling small holes on opposite side of my print. With about 20% infill I then used a syringe to push epoxy and silicone glue through two different parts. I used a transparent filament with about 2 or 3 walls. It drastically changed the feel of the parts. You should try testing some hooks that have epoxy or silicone in them. My only problem is that the epoxy got pretty hot.

[@Makak0007]

Use epoxy which cures slowly (as opposed to regular epoxy). This way you generate the same amount of heat during chemical reaction but you have much longer time to dissipate it, therefore the max. temerature stays way lover.

[@Makak0007]

lover = lower

[@angry_zergling]

Oh that's so awesome I just got into 3D printing, had some parts that needed extra rigidity, and was thinking of the exact same thing! cylindrical voids running the length of the print injected with something, or geometry resembling lightening cuts in the appropriate orientation filled with JB weld.

[@theKashConnoisseur]

Nylon will appear to be quite stiff and strong fresh from the oven. But take care, as the print adsorbs moisture from the air, the mechanical properties of the nylon change and it becomes more flexible and less stiff. Some people take the initial stiffness to indicate that Nylon can be stiffened from heat treatment, but they fail to acknowledge the temporary nature of it. Annealing Polymaker's PC-Max blend will be fine, but to anneal real, pure PC prints you need a precision temperature controlled oven. We're talking being able to control temps to a 10c rise over the course of an hour sort of thing. Without such control, you might as well not bother annealing pure PC as it won't be beneficial. Of course, it's better to just print PC in a 120c chamber to begin with so there's not any printed in stresses resulting from the part cooling too fast, but most people don't have setups capable of that.

[@anyuferrari]

Thank you very much for this information! I was looking everywhere for a plastic that can stand both about 100ºC and some steam pressure. I´ll try now with PLA, PET and HIPS and annealing them. You helped me a lot!

[@mcoozfpvish823]

man your videos are so informative... deftly got me hooked

[@jcugnoni]

Great video. Another property that would be interesting to test is the creep resistance. I have had several PLA part fail over time under constant load (preloaded assembly for example). I guess that increase in crystalinity could reduce the creep rate. For the load, you could compare several heat treatments at 70% to 80% of ultimate strength for example.

[@SeanCMonahan]

I've been testing how annealing Inland PLA+ test hooks affects material creep for the past couple months. (I think Inland PLA+ is made by eSun, but I haven't been able to get confirmation yet.) I annealed half of the C creep test loops at 85°C for two hours on the print bed with some a paper foam insulation on top. I've had the two kinds of hooks loaded continuously with 3 lbs. (about 1.36 kg) for more than a month now. The gap on the unannealed part has grown from 2.0 mm to 18.1 mm, whereas the annealed part is steady at just 7.3 mm! I think it might be an alloy of PLA and PBT, both of which are semicrystalline.

[@jonathanramirez4183]

I just tried annealing Proto-pasta PLA in sand and had great results. I put the parts in a glass baking dish, covered in 70 mesh high purity silica sand and left a probe in the center of the sand/glass plate setup. I used a convection oven. It took about an hour to reach 100C in the middle; I held it for 10 and then turned the oven off and left everything in there to cool. I was pleased with dimensional stability of my parts.

[@SeanCMonahan]

Did you hold it for ten _minutes_ or ten _hours_ when annealing the PLA in sand?

[@EmilyTestAccount]

but what about the one that melted? can't have layer separation if there aren't any layers :v

[@nekononiaow]

This is an absolutely valid remark. Although the part looks different it may actually be much more functional strength wise. He should definitely test it.

[@calvindibartolo2686]

@@nekononiaow generally though being a puddle loses a crystalline structure. I imagine it'd actually be significantly weaker.......... at least weaker than the flat-printed hooks. Not sure about the upright ones though. But, I could be wrong too: after all that part is solid now

[@stevesclocks]

The best way to make a part would be with an injection mold. No need for a 3d printer any more.

[@monad_tcp]

@@stevesclocks if it only it was cheaper making the mold

[@court2379]

I want to see it tested too.

[@Hernerokka84]

Weird thing I've seen in doing some annealing tests of my own is that two different brands of PLA shrunk and expanded in different directions. Both test parts were printed in same orientation and annealed in same orientation as well. Still one of them expanded in X direction and shrunk in Z and the other one did the usual shrinking in X and Y and expanded in Z.

[@paulb8264]

You tried sand but I was wondering how well something that sets like plaster might work? You cast a part, heat treat then wash away the plaster. It sounds like a ton of work but might be worth investigating

[@enjibkk6850]

I was wondering also with plaster... when it has hardened, and assuming that the part is completely filled, could the part then me heated to much higher temperature to completely melt the PLA and sort of have a 'cast PLA' part ?

[@ryanlangan1060]

Using plaster is an interesting idea, but if you're going to all that trouble, then just do an investment casting. Once the part is covered in plaster, you can bake the filament out and cast metal inside. Takes some planning to cast properly, but you get much better parts.

[@chomp7927]

The amount of effort required to make sure the plaster gets into every single nook and cranny, and then taken out when done, would not be worth the 10% gains while maintaining the same dimensions, if it even works. Instead of going to all that hassle, just use something 10% better from the start, it'll be cheaper in the long run too

[@a930913]

Encasing in plaster and reflowing makes the part way stronger. Print 100%, mix plaster and immerse part, wait until set, then bake at 200C until temperature will be even throughout. Let cool and wash away plaster. Keeps a lot of detail, though any air trapped will create a void at the top. I suspect with further research I could print an integral reservoir to fill the void and let the air out of the piece. Fridge clips I was printing kept breaking along lamination lines, but reflowing them removes all lamination.

[@leofortey7561]

@@a930913 you might as well build a rotational mold machine and use plastic pellets. This is FDM. You get what you get.

[@christianmarkussen6412]

Great video as always 👍. I have tried annealing high temperature PLA and found it to have a positive effect. I don't have your test setup but did a simple bend test by hand and found the annealed piece it to be a bit stronger. I did get some warping when I annealed at 100C but none when I used 85C. I had the best results (no warping) when I let the part warm up slowly with the oven rather than putting it into the oven after it was warm. I also let it cool down slowly after an hour of annealing. Supposedly the HTPLA also gets better impact resistens after annealing. It would be great if you could test HTPLA to get some real data on it. Keep up the good work 😀

[@japonicaren]

What brand of HTPLA?

[@christianmarkussen6412]

@@japonicaren I have used the Proto Pasta HTPLA V2 and the HTPLA Carbon fiber. I really like the CF for functional parts that need to be strong and it prints great.

[@TheNorthDevonOrganist]

the expansion in one direction (generally) is caused by the oven heating up all the trapped air bubbles in the material and stretching it.

[@theheadone]

I love your videos! you are truly an asset to the 3D-printing community :) I look forward to all of your future videos!

[@jonboyte]

There are some factors in the heating and cooling. Since heat rises, the top of the part is the last part to cool, thus why you see different expansions in z versus x and y. If you could somehow put the parts in a 3D rotisserie as they go through the process, you should see a more uniform change in size. In large turbines, this is why they have to keep turning during cool down or they bow “upwards”.

[@dinglebop9998]

I work in a glass factory, and toughen/temper glass daily. The glass goes into the furnace, which consists of ceramic rollers running back and forth through the oven at 690-725 degrees celcius, depending on thickness. What is interesting to note is that glass SLUMPING, which is where glass is melted over a material to imprint shapes or designs into it, happen at about 650 degrees celcius. We temper at a higher temperature because it is in the oven for a much shorter time, and is quickly quenched and cooled afterwards to introduce stress in the crystalline structure and leave us with tempered glass. Things to note: The glass we put in is always a flat sheet, so deformation is minimal The glass warps upwards in the oven. As the edges heat up much quicker than the center, they lift up, and once the center heats up to a similar temperature, they lower back down (but this leaves the glass slightly warped). It can be counteracted by having air of varying intensity blown onto the glass while it heats. Rounded corners are much easier to work with since the stresses are less localised. Any holes put into the glass are generally countersunk for the same reason as having rounded corners, but they must have a diameter wider than or equal to the thickness of the glass, else the glass will most likely break during quenching and cooling. The heat is absorbed into the glass not just from the air in the furnace, but mostly comes from the ceramic rollers. A smaller panel will overheat and distort less if it travels over only a few rollers, rather than absorbing the heat back and forth across all rollers. A few seconds makes a difference. 12mm thick glass will be in the furnace for a little over 600 seconds. You can consistently have panels break at the stock temperatures, but adding only 15-20 seconds can make them all come out perfect. A few degrees makes a difference. The heaters on the furnace are top and bottom, and the top is set to a lower temperature since heat rises from the bottom. You get a sort of average between the heaters, on the rollers, but the heat is quickly sucked out from glass going into the furnace. A couple of degrees too hot or too cold can make a huge difference in the quality of the glass coming out. Colour and emissivity is important. The darker and less reflecting a panel is, the more heat it will absorb, and vice versa. Seeing PLA in the oven feels kind of redundant to me. You can't accurately regulate the temperatures in the oven, especially since you need to open the door and let heat out to put the plastic in. Having varying, unsupported shapes, such as the fan shroud. You might benefit from leaving supports on the open gap between the fan shroud and removing it after processing it. I think maybe having flat specimens only, you would automatically see more consistent results, since the heat is more uniformly distributed and warping can be minimal, but with no way to apply forces to counteract any warping, it is kind of inevitable in a conventional oven. I know I'm late to this channel/video and I can't imagine many will read this, but just food for thought.

[@scotticus66]

hey i have been using methylene chloride to make pneumatic fittings take pressures of 150 psi and other water tight parts and fuzzes layers well.

[@ChiralSymmetry]

Thanks for the video! Very interesting. Two things you may want to investigate in the future for annealing of PLA: (1) Some manufacturers make PLA that is specifically designed to be annealed. My understanding is that these types of PLA have solid particles included in the PLA that are supposed to help "seed" the microcrystalization process. (2) I think there was speculation that PLA with pigments (colored solid particles) would more easily crystalize than PLA with dyes (colored chemical dissolved in the PLA as a solution; no particles). If you have time, I would be really interested to see you perform similar tests on, say, white-opaque PLA (which very likely has pigments like titanium dioxide, zinc oxide, etc.) as well as PLA that is specifically designed to be annealed. I have no idea if there would be any difference in results. There are numerous academic papers on annealing PLA and PLA crystallinity. It would be interesting to see if your results are roughly the same as theirs. They studied things like annealing times and temperatures (crystallinity vs time at a given temperature), mechanical properties, and microstructure.

[@panicraptor2837]

If you want really strong parts, create 0% infill and then inject epoxy or other glue components.

[@woopdeedoodaa]

You can still use gyroid infill with this process.

[@OzAndyify]

Interesting. I might try this with PU.

[@TheMastaRob]

I have a bunch of parts on my CNC machine that I designed to be fill with epoxy granite, works really well.

[@Daekar3]

I have done this and it turned out fairly well at small scale.

[@JSCB-365]

UV resin could be used as infil with translucent filaments.

[@rogerneilhogg]

Hi. I swear by the. Using 3D fillies pla plus. 100 c for 30 min. Raises its temperature stability to over 100c. For parts that may get hot in a car it’s a must. Shrinkage is only 1.5 pct xy and expands 1 pct z. I don’t use a cool down step. Whip out of oven while hot and then clamp them down on a cold metal surface. Also have some wooden jigs to hold the critical dimensions in place during ht. All this adds up to quality stable parts that look great and take the very hot Australian sun. Strength is also much better. I have tried this on several pla brands and not all respond the same. Stephan. You should do these tests on ht pla or pla plus. People will be put off based on this video. It’s never a blobby disaster for me with ht. Just get the right material.

[@Serachja]

Great video, thanks for the upload. In case you try it with ABS, I just finished a test myself. I think Thomas did something similar but he chose around 105°C for the annealing temperature for both PLA&ABS. I just did the annealing of ABS at 140°C. The reason being, that PLA has a glas transition temp (TG) of 60-65°C and ABS at 105°C. I've seen that the annealing of PLA works at around 100°C, so 40°C above its TG. Therefore ABS has to be annealed at around 145°C. My Part shrank but the geometry remained ok. All the best with your experiments! Edit: sorry it wasn't Thomas video with the ABS, it was your video as well. It's name was temperature resistance after annealing and you inserted the parts at 110°C (PLA,PETG,ABS). I would suggest setting the temperature 40°C above the TG of the material being annealed.

[@rmatveev]

Such a high annealing temperature is not possible for parts should be accurate in dimensions. ABS is a material of interest for me as well.

[@ronholder5844]

I tried to anneal a Hero Me duct by using an electric water heating pot, which has buttons to reach and maintain several different temperatures. (I love it for making tea.) My parts were put inside a plastic ziplock bag. The water was preheated before I put the parts in. I had read an article on what temperature was best to use and used that. After half an hour in the water, they were too warped to use. At that point I decided I had to get new PTFE tubing and some PETG filament if I wanted a duct that would hold up to long term use. I am assuming that to maintain the temperature, while heating, some of the water got too hot. Haven't watched the video yet but may learn how to do it in a way that will keep PLA from deforming.

[@tstevens06ts]

I have used PLA in my car. Initially PLA was softened by sun heated ambient the first time it was exposed. The next day and other days that were hotter it did not soften again.

[@AquariumsToGo]

I live in Queensland...so I had something more akin to a blob after the first day.

[@antone.henderson]

Thanks for the enlightenment. Explaining a complex matter in an easy to comprehend format is no easy undertaking. Regards Tony

[@jack0cat]

I’m here because the 3D printing nerd suggested that I check your channel out. I’m glad I did and I subscribed.

[@tinkerman-q]

Don't know if anything changed from then to now or if it is just the PLA brand I used. But my eSun black PLA+ became indestructible after doing rudimentary annealing. Really, I'd use it as bullet proof vest. The flat playing card like surface object I printed has around 2mm of thickness. My precious PETG print of the same part would make crackling sounds just by applying slight pressure on the sides. Unannealed would just break very easily. Not after taking going to the sauna. First thing I noticed is that the layers seem to have fused and surfaces looked like solid paint. And no matter how hard I tried to bend it. It just refused to make any level of deformation. Fel like bending metal .

[@antalz]

I tried annealing myself, but the shrinkage causes buckling on walls, which is visibly clearly on the fan shroud. Annealing is only worth it for functional parts, but functional parts need to be accurate, so you can't really do anything with this. The only thing I still want to try is bolting down a part to a metal plate, and then annealing a part while it's constrained. I tried some filaments that were specifically advertised for annealing, 3dktop Berlin, volcano PLA and something else, but they still warp. The process is interesting from a scientific standpoint, but engineering wise, for now, seems entirely useless.

[@prkl3]

Nice Work Dude! I have annieled some pla mic adapters immersed in 75c water for 30 mins. Old coffee maker as a bath, since it has 75c thermostat. Parts in ziplock bag with an aluminium plate ensuring parts flatness and old Shure mic body ensuring tight fit after annealing. Works fine and heat transfer is uniform if you get all the air out of the bag. You really should test this. Alltho better way might be a Sous Vide cooker and real vacuum bags. Keep up the good work!

[@jakubmaurenc6781]

I have tried to print some parts at 100% infill, then put them into a plaster and heated them to nearly melting point of pla. The idea was that all layers will fuse together. Then the plaster is just "disolved" in water. But my test were unsuccesfull probably due to a low temperature. And i never tried again, but i thing that i could make the part really strong. Would be nice to see you test that.

[@barndweller4573]

This sounds something like what we do when casting bullets our of lead alloys. Yes our temps are much higher (720 degrees F). We drop the hot bullet as fast as we can out of the mold as soon as it changes from a liquid to a solid into a bucket of water, the colder the better (Does not stay cold very long). We do this to increase hardness. It has something to do with crystals in the alloy. I wonder if cooling fast is possible and if it would make a difference? Thank you for your videos, I have ordered a 3D printer and have been watching your videos. I want to use my 3D Printer to make Antenna Parts for Amateur Radio.

[@Thomllama]

Awesome as always,!!! I do hope you try HT PLA’ s generally made from a raw 850 or 870 resin. These PLA’s are higher temp and generally take to annealing much better than the standard cheaper PLA resins most filaments are made from!

[@pomprocks]

I'd love to see tests with 870.

[@woopdeedoodaa]

Please try annealing parts immersed in common household oils, castor, canola/rapeseed or vegetable oils in particular. Its would be interesting to see the different effects that each oil had (if any) due to chemical compatibility and the duration and temperature of the annealing process. If you use the gyroid infill pattern and had drain/fill holes in the part where it wouldn't affect strength then, as its a "porous", the oil could evenly contact all of the material evenly, reducing warping, and as it would allow the parts to be brought up to temperature evenly it should more throughly and evenly annealing the part. I'd suggest a process of annealing at 45c, 60c and ~75c for 20, 40 and 60 minutes. That would be a 3x3 matrix of results. Ideally one such test for each oil type. I think this is the most complete process that could be done in the home environment.

[@johndavid4825]

I just ran into these videos. I love them! I thought I would comment on two things. The first is that I have never seen a DIY notched impact machine before. Brilliant. The second is that you could also print a little finger (similar to the max travel on the imact tester) for your finger torque wrench to record the max there as well.

[@kwad3d10]

Thanks for keeping your channel "real". I can't stand other fake printer channels where the host talks funny and acts fake on camera for subs. Not to mention they don't even know how to properly tune a printer and post prints covered in cobweb strings

[@CNCKitchen]

Thank you!

[@S41t4r4]

There are fake ones?

[@kwad3d10]

@@S41t4r4 Only one in particular off the top of my head. but everyone has seen the channel. its a great channel for new 3d printer users but anybody with some printing experience can see their lack of knowledge displayed by the quality of their prints.

[@AS-ug2vq]

@@kwad3d10 who?

[@kwad3d10]

I don't want to point fingers.... just keep your eyes open. Im not saying im a expert printer or anything but I shouldn't have less strings on my TPU prints than their PLA ones LOL

[@aaronbrown7750]

I believe the pla+ and some HTPLA's are better equipped to do this with, as they are supposed to warp less during the annealing process, like how you found that the volcano one warped less then the crystal blue. Makergeeks used to sell a "raptor" line pla that was like $15 extra that was supposedly made to be annealed. I have several spools of it, but have only tried it once with putting a part in some boiling water for 10 or so min. It was a dragon print and the wings kinda ended up sagging down a bit, but after it went soft, it hardened back up in like 4-5 seconds and you couldn't get it to be pliable anymore. I ended up snapping the wings off trying to get them back lined up..

[@jparky1972]

I would have been interested in finding out what the tests said against the hook that really melted. That one would really have merged the layers. So perhaps you should consider testing it anyway.

[@Personnenenparle]

@_ David _ the surface area at the breaking point would be similar sizes, so it would be very comparable.

[@jparky1972]

@_ David _ Yes. I appreciate that. It's more out of pure intrigue than anything else. If results are noticeably stronger. Then maybe an experiment with 100% infil with the piece placed in a mould in the oven to keep its overall shape and dimensions. I appreciate that this then more or less turns the part into an injection moulded part. But as I said. Just intrigued, that's all.

[@olleo_ol]

What if you try annealing in silicone mold to avoid warping during annealing process? Silicone form if something not difficult to make and it will keep form while heated.

If you're worried about the bend modulus changing, could you use your 3d scanner to scan the deformed test piece then 3d print the control with that mesh and compare those? Also agree with what others have mentioned about trapped air potentially causing further layer adhesion. The fact that your XY shrinks and Z pillows in that cube corner calibration piece shows that air is trapped (albiet the infill space is more to blame there). Could you do zero perimeter pieces or cut/sand external faces to expose solid linear infills and test if giving air between extrusions a place to escape can improve your results further?

[@GregAtlas]

I hope you cover HTPLA and PLA+ That was a great idea to use sand. I've used hot sand to bend PVC pipes without kinking for costume projects. It makes the heating more even and also prevents the PVC pipe from collapsing in on itself. I hope you continue to experiment using the sand technique and try the larger container to be thorough to see if that helps any. You also might want to try heating the sand first before pouring it in to see what affect it might have.

[@MacroAggressor]

Have you considered using an oil bath (maybe with a sous vide) to maintain more consistent annealing temps? Might help with warping. Looking forward to the stress relief video.

[@jonaanz8071]

At 7:45, what does data point mean on the plot? Is it the number of tests don't for that number? Or the experiment number for one independent experiment?

[@mindsofgreatness]

First learning about Volcano PLA from Form Futura, going to test out their 50 gram to see how it goes before picking up a large spool. Thanks for sharing your research!

[@dvdganon0812]

actually i have some idea. if you can use a molding send. like they use in aluminum casting. you can get the oven to 220 c more or less. and get full melting and adhesion of the plastic. this way. we can make "molded plastic" parts. but instead of making a mold and inject the plastic. we first 3d print the part and put it in a sand mold. the mold hold the structure. and the part is fully melting inside and becoming one piece of plastic. very interesting to see what will happen. if you smooth the part a little bit before this process, you can get even smoother molded part. i also believe that the sand will not get inside the layers spaces, if you print in high resolution. so maybe no need to smooth the part. (0.12res) but you probably will get the rough texture of the sand.

[@Sleepery22]

Thanks for this video! I followed your instructions and tried annealing mechanical parts printed with eSun PLA+ (in my kitchen oven). I got some minor deformations, but I was able to Dremel them and use the part. They definitely feel stronger, but I can't measure how much really..

[@BOSS-bk2jx]

Interesting investigation as usual... I really adore the way you apply scientific method to your investigations. Keep up the good work. I wonder if the layer adhesion quality is related to the hot plastic being reactive to humidity or oxygen in the air, or perhaps some air is trapped at the interface between layers reducing the effective connection between them. Is it possible for you to make an investigation about that idea? [3D printing in a vacuum, different pressure levels or in an inert atmosphere]

[@ScottyMakesStuff]

Hi Stefan, thanks for taking the time to educate the larger 3D printing community. It's been bugging me a bit but I think the phenomenon of the annealed prints becoming less amorphous may not be correct. I suspect it's a bit more complex than that. I can't say I know the real answer but a typical thermoplastic should become more amorphous when heated above it's glass transition as the stresses that the printing has applied are relieved somewhat so that the polymers individual strings can go back to a relaxed state which is why we see some XY decreases and Z increases in size. Could the print lines be lensing the light? Maybe there's a polymer chemist here that can put me in my place :)

[@georgelaskaris1682]

Boiling Water Annealing. I made a 5 inch screen shroud for a backup camera installation on my wifes car about x170mm y130mm z130mm from pla and covered it with fake leather upholstery ! So in about 5 days it just melted and annealed rock hard on the dash under the sun. I then reprinted compensating about +5% on x and y and -4% on z axis. I then annealed in a pot on the stove with BOILING WATER for 35-40 minutes and let cool. Short story, The thing is now on the dash over 6 months under the Greek sun (60-70 degrees on the front dash) and it has not deformed in any way, I did make a few small 100mm x10mm x5mm test print strips before with the 100mm test print on each axis. I suppose the boil anneal process keeps preasure on all surfaces the same for minimal deforming. I dont know about strength of prints but temperature resistance increase for prints is about 30-40%. Parts annealed in boiling water have to be secured and not dance around or some deformation may occur . Thanks for all the great tests you do for us.

[@danapatelzick594]

Your work is really done well. Please continue.

[@jacksin3323]

Heres a tip for using a home oven vs a professional rig... Your home oven has a 25°F swing in each direction, because of how it samples and corrects temp changes... use a foil "tent" or keep your pieces on a cookie sheet with another cookie sheet on top to act as a heat sink/thermal regulator. I heat treat steels in my home oven. It also helps to keep a second thermo inside of the oven. I keep 2, one sampling the heat in the oven, and one inside of the cookie sheets. You need to stabilize temps on product to yield ANY scientific results worth anything. If you need more tips, lmk. I know how to mod an open door toaster into a great heat treat oven.

[@kerricaine]

one technique i've been trying is to make a silicone mold of a printed part, and take ground up PLA remnants (supports, rafts, failed prints) melt them till it's almost clay-like in it's consistency, and then press it into the mold. you essentially get a 100% solid model. that being said, i've never tried anything to measure tensile strength of these PLA casts, but i would love to see how that would compare if you were to try it!

[@Niloc1922]

Do you have a masters in engineering? You are so smart, and I love that you use your knowledge for fun, yet very scientific tests.

[@lm6036]

You don't need something as artificial as a degree to be smart :)

[@Niloc1922]

@@lm6036 Sure, but it doesn't hurt.

[@kingmasterlord]

@@Niloc1922 student loans disagree

[@Niloc1922]

King Masterlord fair enough, however, it’s almost free for Germans to get an undergraduate or graduate degree. Getting a degree teaches you a lot at any well respected school.

[@kingmasterlord]

@@Niloc1922 yeah that would be nice, but as an American in this day and age I'm in a unique position to value targeted self education and as-needed research and study preferentially.

[@marcmengel1]

What if, instead of whole-part-in-the-oven annealing, you heat treated specific areas with a small flame torch to fuse the layers, let each section cool before moving on to reduce warpage? You could do that to the stress-point of a vertically printed hook and see if it strengthens the strain point... The problem I guess is not overheating it...

[@Personnenenparle]

I use a soldering iron with more filament to reinforce the layer this way. Heatguns can do but the warping is way worse without a lot of practice. Also the heat dont reach very far in, so to just dip the whole thing in epoxy make it just as strong if not stronger

[@jeffwells641]

You're more likely to add as many or more stress points as you remove. To remove stress you need to normalize temperatures between regions, and the only way to do that effectively is to heat the entire part as evenly as possible.

[@michroz]

I was looking for data about the PETG annealing and couldn't find the Part 2 video :(

[@ZerqTM]

this is useful... reducing translucency helps a lot... i am making some key chains and i really did not like the translucency... this could make it look a loot better! awesome and very helpful!

[@SimonFiliatrault]

Thanks for this! I always wondered if it would help the layer adhesion, a bit of a bummer it's not. I think we would need a printer that would be able to rotate a piece while printing and have a layers added horizontally on top of vertical ones... But I cannot think how a machine like this could work! I did many parts in two sub parts, one printed horizontally and the other vertically and glued together after to augment the resistance, works well, but more work in design and built

[@buckmanstijn]

i work in a plastic lab and i do this all day ^^ :-D you test good !

[@mbalunovic]

Have not used this before but will definitely do that for parts that are likely to experience raised temps dooring life.

[@Deqster]

Oh, you're already on track to investigate inter-layer adhesion. Not looking like there is any particular advantage to heating for adhesion. What is really interesting is the smaller warppage when you stress-relieve first... that could prove useful. You might try burying the part in sand, then vibrating to settle the particulates, then compressing them with a lid/clamp. Locking the grains together might help minimize the possibility of the warping part displacing sand only held in place by gravity. It might also crush the part a little.... would have to test it.

[@Royvan7]

would it be possible to remelt the plastic and retain the parts shape. you could encase the part in plaster or something else that will retain its shape at high temps for support.

[@skaltura]

I use quick passes with blow torch on parts with mechanical strength requirements. This gets the surface layers annealed, and sometimes even melting without distorting the whole part.

[@rhynoorhyon5291]

I wonder if pressure applied during the heating process would allow for layer bonding. Perhaps a weight on some packed sand, with the layers you'd like to bond, parallel to the ground?

[@Classcelementmultimedia]

100% infill works the best for annealing pla

[@skyak4493]

Stephan, Nice job but I think it only proves that one specific PLA does not strengthen with heat treating. I heat treat PLA for heat and creep resistance. For layer bond strength I turn off the part cooling fan and/or use a larger nozzle. For overhangs I am experimenting with air blown only at the overhangs from the side and below by ducts fixed to the build surface. This may sound like a lot of screwing around but my theory is that I save time and inventory by making everything in one foolproof material.

[@georgekrapohl2406]

Thanks This was very insightfull and learned alot. I was wondering if this annealing process if it followed, a reflow soldering temerature curve where you heat the parts to a specific temp for a certain time that every object can reach that temp then ramp up the temp for short period then decrease the temp slowly. Probally achieve the same results..... Or will it?

[@beaconofwierd1883]

I would be very interested to know if PLA deforms over time. I heard that it slowly deforms under pressure, but I don’t know if this is because the pressure is high enough to cause plastic deformation or if PLA deforms over time even if it is not in the plastic deformation pressure zone.

[@CNCKitchen]

Is on my list!

[@brucebelvin2058]

I never understood the name CNC Kitchen until now. PLA cookies anyone?

[@macmaniacal]

Have you made a video about epoxy filling parts? Obviously it'll be much stronger, but how much would be cool to see.

[@donamills]

So damn informative. You save me and the community soooo much time. Thank you.

[@pr0xZen]

I only have an old DaVinci Mini, got it 2nd hand for cheap along with a roll of blank tags, to learn and print some handy little gadgets. This can be very useful to try, as many prints is various holders and adapters used for solder equipment ("functional prints"). It's not directly in contact with hundreds of degrees, but it can be near so radiative heat exposure often up to 80-90°C, which has already messed up some of my printed parts. Btw, the DaVinci doesn't have a heated bed,and its construction doesn't seem to make adding one a realistic task. Would plopping an enclosure over it, help notably with bed adhesion? Room temp is usually 25-26°C when printing, but I assume a box around the whole printer could probably increase the effective ambient temp for prints..?

[@MikhaelHausgeist]

Sand is too soft even if You pressurised it. If mechanical properties needed to be impruved without warping and geometry deformation maybe use a gypsum? Print and pour in gypsum, wait a little before it will dry out and only then put into owen with 70-80% of melting/printing temperatures (if material melt on 100 degrees so use 70-80 degrees). Dryed gipsum didn't change the shape so printed detail can't chenging shape also, but pure gipsum pretty easy to ramove and reuse. It be useable only with details like hooks You use, but I think use it for some hollow details was screwed... Also some one using aceton to remove layers texture and I think it can help to adhesion and stranghtened details too. Sorry if video about already was I did't see it yet.

[@ol4er]

PETG gets also crystalline! actually you buy PET as you give the time after it get crystalline ... The sintering (how you call the treatment you have done) is a slow process and you need to be 2/3 of the melt temperature... so I think maybe ABS is the better material to try it, the problem here is you didn’t get any support and it could happen that it just melts ... What I really think you can try is to form first the crystallines in pla and after it get crystalline you heating it up close under the melting temperature so the crystallines keeping the structure... and your material can sinter together...

[@twiddler71]

What about testing PLA plus or PLA Pro? Also, would annealing improve thermal resistance enough to match that of ABS or PETG?

[@Polymate3D]

Nice testing as always. I have wondered about a infra red heat lamp is use during printing as I did it before to reduce warping but it keeping the previous layer warmer may help with layer adhesion

[@BuzZ.]

Wouldnt it be cool to have a duble extrusion 3d printer that would have really high temp plastic in one nozzle and like pla in other. So it would print the shell of the part and than crank up the bed temp to 220°C and fill the inside with pla. It would make really strong parts

[@trischas.2809]

I found that brushing over a surface with a soldering iron can increase the stability some, but that is pretty much a very strategic re-melting of the outer shell.

[@zachmarks6337]

What doing boiling PLA prints do, since the glass temp is below water's boiling point?

[@chain3519]

Or Even better, double boiling

[@TangoDeltaDelta]

I have used a heat gun to remove "wisps" that sometimes appear, and if used VERY carefully, it can slightly smooth layer lines without warping the shape. It isn't consistent, however, and easy to mess up.

[@edwardure]

What about using a blow torch on the surface with some kind of rotation? This might even help to smooth the print and increase the strength somewhat at least the surface layers. Or what about a rotisserie oven.

[@herseem]

Thanks for this video, you've persuaded me not to bother annealing PLA, which has inevitably saved me a load of time and money

[@elrondmcbong467]

I absolutely love PLA, it's sturdy, tough, pretty abrasion ressistent, comes in a gazillion of colours, is cheap, stupid easy to print, almost impossible to ignite, doesn't need any mods for your printer and doesn't release nasty fumes while printing. The only real downside really is its low temperature it can ressist against deforming. If you could bring the point where it looses form stability up to 80°C, 90°C or even around 100°C with annealing, it would be pretty much the perfect allround filament from which you even can print car interior parts without the worry of warping like crazy.

[@lornelorne5727]

"doesn't release nasty fumes while printing" - false. Be careful with that. It's a common misconception that PLA printing is totally safe. Some people are even printing in their bedrooms overnight. Shocking. You don't want to be breathing this stuff in. It's not as bad as ABS but it still releases harmful fumes and clouds of micro plastics. There are studies showing this. And long term effects are unknown.

[@stang1966gt]

Hi Stefan! Great channel with tons of educational material. I am interested to increase part strength. Was wondering if epoxy coating will help. Or even wrap monofilament around the parts and then epoxy coat. Thank you

[@akumabito2008]

Could you rig up a tiny spray nozzle that sprays a minuscule amount of acetone in front of the print nozzle? Maybe that way you could solvent weld individual layers together.

[@jasonm2477]

when you were placing them in tightly packed sand did you enclose the sand? I have found warping almost went away when tightly packed and closed in a container, that being said itw as way more effort than its worth and i'd never bother doing it again

[@BOTmaster15]

With that much work why bother with pla anymore. Just cast whole part. It won't be much more work but it will be worth it.

[@andrewdowling6321]

YES! Really filament dependent. But better heat resistance, better strength. However, I had some warping as well. I found Z elongation, with XY shrinkage. I found other materials also like some annealing. PETG, ABS. Nylon does not seem to care.

[@thaumaturgicresearchcounci4180]

You should have a go at hot isostatic pressing of some parts. It's commonly done for high integrity castings, powder metallurgy, metal injection moulded parts. Would be interesting to see how it might work.

[@jscancella]

What about surrounding the part with plaster of Paris and then heating until the pla melts? The plaster of Paris should keep the dimensions but is easy to remove by submersing in water.