One aspect of temperature that you didn't cover in this video, but have in past ones: thermal expansion. The hotter you print, the more the plastic expands, and therefore contracts while cooling... This is one of the main factors in warping and necessitates a heated build chamber for certain materials. The low temps parts aren't shrinking as much and are tighter when put in the same hole as a part printed at a higher temp. Also print speed is a huge factor in print temperature. The bottom line is heat transfer, how much heat is getting into the plastic, what that heat does, and how long it stays there. If I want stronger prints with better adhered layers, I print slower. If strength isn't a factor and I need a faster print, I turn up the temp with the speed.
What would you consider as slow printing? I can most certainly confirm that printing Cf nylon at 30mm/s is much weaker than printing the exact same part at 60mm/s. By printing faster, the lower layers are actually at a higher temperature thus improving bonding strength. You can take this further by printing at 60-80mm/s but at far higher temperatures than recommended. For example, I print Taulmans CF nylon at ~70mm/s at 280-285°C. They recommend 255-260°C. This makes the layer adhesion insanely strong and the part overall is leagues stronger and stiffer. The downside is supports will bond way too well and warping becomes a factor to be weary of.
I know im 2 years behind on this comment, but I am also finding that in some cases not cooling quickly enough with certain filaments (in my case polymaker polylite pla pro) Causes filament on overhands to curl upward due to still being too hot when the nozzle runs back over them and leaves them curled upwards. So in some cases cooling is very important, especially after the first few layers!
Cold prints getting stuck in the impact test jig: parts printed at lower temperatures likely shrink less after printing, resulting in larger parts and a tighter fit.
All white filaments are a hassle to me, no matter the polymer. PLA, PETG, ASA, ABS, TPU, no matter what, I need at least two prints to get acceptable results.
The "milky white" PETG I get from California Filaments has always printed fine for me. My guess is that they have less of the white pigment - hence the semi-translucent "milky" appearance. If you really want white in PETG, you might give that a try.
For me, 10 ° under high number on filament spool has always worked well. Then bed pla 55 ° and Petg 85 ° Biggest fix I’ve learn for bed adhesion and avoiding fuzzy first lays with a PEI Flex sheet is just occasionally washing it in the sink under hot water with dawn dish detergent. Try this first when things go wrong all of the sudden. I learned this after days of settings chasing. Great video!
@@muffty1337 Another UA-cam 3D printer/CNC content creator (Channel is "CNC Kitchen"). Thomas and Stefan have Podcast together (Podcast is "The Melt Zone").
honestly, temperature settings are something I set on a per-print basis. Things that I factor in are: Nozzle size, purpose of the print, room temperature, are there any large bridges etc. I generally print PLA with 200-210 Celsius, a bit lower for 0.2 nozzle, about 220 with a 0.6/0.8 nozzle(those are mostly vasae mode prints where I want it to hold water and usually increase flow to about 110% ish)
11:40 "I should note that the default temperature for Prusament PETG, on PrusaSlicer on a Prusa MK3 is 250 Prusa-degrees" I know Prusa have printers and slicers but I didn't know they had their own units 😂
All the post-soviet 3d printing enthusiasts refer to "parrots", not degrees. This origins from an old cartoon scene with character measuring a big snakes body length with a parrot. Every printer reports temperature a bit off (most of them are Chinese here, so more prone to this behavior) so sharing what temperature you use is more "scientific" if you mention the units may vary this way:)
Most of the thermistors are manufacturered in China. Even on American and German 3D printers, so mostly their temperatures are the same as the Chinese ones. You can buy thermistors with different temperature tolerances. All from China. So it depends on what is installed and where exactly it is located in measurement. Also the thermistors are all rated at 25C but have different thermal constants. But the manufacturers are aware of what these are and choose them specifically. The possibility is manufacturers don't test a part to confirm the characteristic tolerance is within spec.
I have also noticed PLA having a tendency of printing less glossy, more matte at lower temperatures, which is why I tend to lower the temperature somewhat for decorative items; matte items just tend to look better than glossy. I haven't bothered increasing temperatures and instead just adjust infill and/or shells, if I need stronger parts -- I haven't done any proper measurements, but I haven't seen any benefit in increased temps.
Watching this makes me glad I can create project profiles directly on my old faithful Ultimaker S3 dual nozzle printer (with NFC filament recognition) (auto levelling & heating). Using preset profiles that I found can include all known and customisable settings, making it easy for novices like me, to start at commercial grade printing qualities, without the hassle of knowing in advance what's required, just splice and load to get projects completed quickly, with a professional finish that requires little to no post processing. Thanks for sharing your invaluable information. 👍
9:30 My guess would be, that there's a higher pressure build up in the nozzle, when you print colder. And because of that pressure, the filament will bloat up more, when leaving the nozzle.
@@erikwithaknotac Except that the user sets the Extrusion Multiplier so that the final extrusion width should match the value entered in the slicer for extrusion width, theoretically taking shrinkage out of the equation for the baseline. Also, for the lower temperatures, thermal expansion plays a much lower role than die swell for governing extrusion width (you can verify this by observing the relative change in line width with change in temperature vs change in extrusion speed). I am assuming that Tom didn't change the EM settings for each temperature, but just used the stock setting for the entire run, which means that the main contributor to extrusion width is going to be die swell.
thank you so much, i always have problems with dimensions of my parts and tried everything to fix it. I will now test higher temp bc i have always printed at 195°
Thank you Thomas for a lot of work to do all these tests. I'm glad you got back to the "old" tracks when you focused on the topic, not personal tours and sometimes strange opinions and comments. There was a point where I saw too much irritation in your videos that pissed me off enough that I stopped following your channel. Let's focus on the topic without intrusive private content. I appreciate you for that. And many others, probably too. Regards.
Thanks for the test! I do appreciate the time it takes to print all those test samples =) I usually found that "glittery" PLA prints way smoother welds at 225 compared to 215 that i actually found works best for run of the mill single color PLA.
The trouble is, each printer and each brand of filament is going to be slightly different, meaning that really we still need to do at least some calibration with our printers and filaments no matter how much information we have. This testing, and other testing like it, definitely gives us a helping hand to get closer with less testing, but the testing will still be needed.
3 factors will impact your dimensional accuracy in regards to temperature. 1) shrink as the part cools 2) viscosity in the nozzle (pressures) 3) viscosity of extruded material, allowing more creep. Each can be measured and calibrated to identify the cause, then correct. You will need to adjust using a couple test prints.
I had to lower temperatures when used 0.2 nozzle. When print in low height rows standard 230C degrees with PETG result in deformations and stringing, so I use 220C instead. Which gave me decent quality on small detail.
i print pla in 210 and petg in 240 for me best results , i depends on few more things like temp alone in my experience. my printers stands in an enclosure and there i can slightly lower my temps
Good tips but in general it's simply easier to pick the highest temperature which allows bridges and overhangs to work well. It's usually very close to the optimal temperature, there's little to be gained by going higher.
Lower temp parts are overdimensioned because leaving the nozzle retaining the stress of a larger filament expand in XY and contracts in Z to retain its previous shape. Raising temps or using turbulent nozzles like CHT reduce the effect.
I'm guessing the cold parts are coming out oversized due to die swell. Basically you have a greater temperature gradient as not all the plastic is coming out at the same level of "melted". This leads to internal stresses that can cause the filament to expand out of the nozzle
Thanks for the info...however in engineering terms, impact strength is different to tensile strength. Strength in printed parts with regards to heat and adhesion properties is always going to be governed by application needs. So, print variables should be practiced depending on application. No one setting is actually better than the next. That would be my conclusion. Thanks for the great and interesting content. Much appreciated.
If you print below temperature, you will have some solid and soft mix on the polymer, it will make it wiggle while it leaves the nozzle making the tolerances bigger
For cold extrusion temps, the filament is not entirely molten but soft enough to squeeze through the nozzle and then expands after it exits causing the layers to be thicker thus poorer tolerance. It may even be molten on the outside since that is the part of the filament in direct contact with the heater block but with a soft inner core not totally hitting the molten temp. You can see this with a zoom camera on the nozzle.
I'm currently using the Bambu Lab 3d printer P1S. It's an enclosed printer. I noticed that the smaller surface area I'm working with, the hotter I need to print, but I'm only heating up the bed from 35C to 55C. The biggest issue I believe I was having, was the Bambu default settings for the cooling fans is maxed out. My parts were flying off the bed. Definitely going to take some time to learn the best settings for heating and cooling.
Thanks for doing science! I've just been printing PLA at the default setting of 200C, except bumping up the first layer to 205C for better bed adhesion at the cost of more elephant's foot. Maybe I need to do some testing myself to see if slightly higher temps would be better for the subsequent layers.
I found that my PETG and PLA prints were getting more and more matte the faster the printer was moving, and I wanted a more glossy and clean look so I increased the temperature as much as I could before the bridges started to sag and then I was able to reach much higher speeds without getting that matte finish. This I think means that the matte finish happens when your filament hasn't had enough time in the hot zone before getting pushed out, so I guess a volcano hotend would help if you print at lower temperatures at faster speeds.
Thanks for your contribution to this type of info. However, what about the affects of fan cooling on layer adhesion. For instance using 15% fan power vs 100% fan on PLA prints. I know personal experience shows this is definitely the case for PETG favoring 15% fan power and not much more for best layer adhesion.
Absolutely. I appreciate the time gone into the video. I just wish this was mentioned. Unless my layer times are low, I print with no fan for PETG to get max strength. It makes a huge difference especially with layer adhesion.
@@karlosss1868 I agree for max strength running petg with 0% fans. But If the print design needs some assistance for some fan cooling for bridging, it is always a balance of quality of overall shape yields vs strength in conjunction with overall quality of a parts intended purpose.
CNC kitchen has a great video on how cooling fan affects part strength. With PLA and PETG you can turn fan down alot but you must print your parts really slow. This will allow the layer to cool enough to not have bad print quality but you must be patient.
my elagoo fillament pla in black says 205 - 230 but a tempreture tower produces best results at 190c i do first layer at 200 but that is quite different to manufactures recommendation. in short print a temp tower on every new fillament batch thats what i do anyway
A good point. A test like this can give you a good sense of the general tendency, but you need to calibrate to your own machine in the end. My gut feel is that consumer machines probably vary enough that any two machines could easily be 5C different for the same indicated temperature. You could check build plates with a simple IR thermometer. But nozzle temp is a bit tougher.
@@wturber my ender 3 s1 bed was about 8° C lower than the temperature sensor reported before I redid the PID tuning and added insulation foam. Now its only 4°C colder than set.
The larger dimensions on parts when printing below their optimal temperature can most likely be explained from non-uniform shrinking in relation to the printing temperature. I have long had the suspicion that shrinkage in 3D printed parts is non-lineair. Meaning that the hotter a print is or the more volume of plastic is deposited the more the part will shrink because of the disturbance in the polymer chains being more or less. Keep in mind that with 3D printing we're at the low-end of the liquid range of most plastics. PETG usually prints fine at 230C whilst I believe it's injection molded at close to 280C~ don't quote me on that, but I know from my own injection molding press that I cant get good shots at the same temp as the printing temp. Long story short; 3D printed polymers, specifically FDM printed polymers most likely shrink more when printed at higher temperatures and less when printed at lower printing temperatures. This could well show up in printing a tower at scaling temperatures during the print and the carefully measuring the print. The mechanism behind it must have something to do with how to polymer chains crystallise. I'm not sure if the amorphous or crystalline nature of a polymer would matter or not.
I never printed matt filament, neither PETG nor PLA. The matt-optics is the result of the filament filled with some stuff (chalk, talc, whatever) and it wears down the nozzle. I’m not surprised that your results were bad.
09:30 Could it be that the material gets stressed from the high nozzle pressure buildup occuring when printing at too low temperatures, causing residual stresses in the material to cause something similar to die swell, messing up the final dimensions?
It’s can also be because the parts shrink less than they do at regular temperatures. Those tenths of a mm could turn a loose fit into a pressfit. The shear stress and resulting die swell you mentioned could also be a reason especially if Thomas printed the parts at the same speed-/ flow settings and only changed the temperatures for the parts. He didn’t mention calibration for the different temperatures which could somewhat falsify the tests.
I second the pressure therory. I think the cause is the higher viscosity of the material at lower temperatures, resulting in more pressure against "itself", thus increasing layer width, because the other directions are constricted.
@@kkpal Die swell does increase at lower temperatures but that is only relevant when printing into free air. When laying down filament its width is determined by the volume per unit length over layer height. With the higher pressure at lower temperatures I would expect the hobbed drive to give a bit less filament, not more, so it is a mystery to me why the parts would get bigger. Perhaps bigger layer start zits due to the extra pressure.
Lower Temperatures at "higher speeds" means that the material is less viscous and as such the extrudate swell (die swell) is more severe which might have influence the tolerances. If you print them at lower speeds the impact test samples might fit better (potentially).
I love the concept of sequential printing, but every time I try the first part comes out fine but the others have terrible first layer extrusion, like when you print without a skirt or staring line and there’s not enough filament in the nozzle at the start of the perimeters.
I've defiantly experienced dimensional shifts when printing hotter. I'm pretty sure it has something to do with thermal expansion of the plastic while printing. Yes the mechanics are making the same moves and the extruder is pushing the same steps resulting in the same mass. (As others has mentioned pressure, mass would be something to look into.) But I think even with the same mass you can get different dimensions because hot parts will shrink more. Say a printer is accurately placing a 0.6mm line on the permitter of a part at 190c, when that part cools down to room temp it will have shrunken down to Xmm. Being less than 0.6mm. The same line *extruded to the same accuracy of 0.6mm* at say 230c, will shrink to Ymm at room temp. But Y will be less than X because Y had more temperature shrinkage, thus the part printed at 230 will have overall smaller dimensions.
Constructive criticism.. reconsider your force to break test methodology. The pipe used as a lever has a variable angle of incidence on the printed test part, when it appears you are trying to test vertical strength.. you are actually testing strength in a constantly changing Y and X vector. Rig up a pulley that is in between the luggage scale and your force input and you will constrain it to the Y axis.
I had to shake my head a bit about this test batch. Firstly, if I'm printing a part for which strength is a concern, you can darn well bet that I'm not going to print with two walls and 15% infill. That's the kind of setting I would use for generally non-functional parts that deal with little or no real stress. For strong parts, you really do often want your part to "pretend" that it is an injected molded part. Why? Because injection molding is expensive and sometimes you want a part to actually do useful work. I don't print my bike tire removal levers with two walls and 15% infill precisely because I'm going to subject them to high bending loads near the limits of the PETG material - much as your bending test does. Secondly, you chose a matte PETG?!?!? Even if you didn't run into the semi predictable problems that you showed (I print a fair bit of matte black PETG because I really like the finish), I would never assume that a matte PETG filament would provide typical PETG results. In looking at matte PETG, it appears to have some kind of filler that gives it the matte finish. I don't know what that filler is, but I'm assuming that it does not increase structural strength and that it probably compromises it. I treat it as a different material than ordinary PETG. If I were to take this kind of time to do a test, I'd pick either ordinary colors that were the same for both materials, or neutral/no pigment colors. In this case, clear and "natural" for PETG and PLA respectively would be preferred. Doing this means you are testing the plastic and not the dyes or fillers. I'm a fan of both Thomas and Stefan. But I found this test video a bit dumbfounding.
I think you misunderstood his explanation about the strength testing parts. He wasn't trying to test ways to make strong parts, he was trying to test the strength of typical printed parts using the most common settings of 2 walls and 15% infill. There are better ways to make strong parts than that. CNC kitchen did a great video on that, it's really most efficient to increase shell thickness. On the second point, I think he was using the standard Prusament PETG that isn't a special matte finish. I had never heard of the matte finish specific PETG though, that sounds really interesting! Have you found the matte black to have significant mechanical weaknesses? That sounds kind of perfect for a project I've got going.
@@evanbarnes9984 I think you missed my point. People printing with only two walls generally aren't very concerned about strength. In situations where strength is any more than a passing issue, people print more and thicker walls - for the exact reasons the CNC Kitchen video outline. I'd also think that having more layers would be make for a statistically better test since with more layer lines, any unusually weaker line would have less relative influence on the results. Maybe his one "noisy" graph would have given better results if more layer lines were involved? To be fair, his two 0.6mm lines are just as thick as three 0.4 mm lines. As for the matte black PETG, I can't say for sure that it isn't as strong. My impression is that its "chalky" nature probably makes for weaker adhesion. But I've never actually tested if. I use the matte because I really like the look. In fact, it can look very nice when combined with the Cura "Fuzzy Skin" feature. If you'd like, I'll do some simple tests. In fact, I'll probably do it either way since this is something I'm a bit curious about myself. As for the look of the filament, search for California Filaments. The have reviews online that often have photos. They also have matte in, I think four colors.
Great to see that prusa has their temps in line! I do get pretty bad stringing with PETG at stock temps though, but I do think that is due to the swampy-ness of Florida more than anything else. Easy to clean up, but a bummer none the less! The impact strength is definitely an interesting one. Those variations could be from layer strength as well either yielding or snapping. Obviously a yield will absorb more than a snap? Not sure if there is correlation there.
Stringing is mostly from not enough cooling for PETG as I had a stock ender 5 pro did tests with it stock before I did the upgraded cooling mod huge difference and no more strings and can even print faster with the new cooling saving time.
@@Bigdog1787 I run mostly Prusas, cooling is not normally an issue. PETG is known to string as it gets a little bit moist. Having ambient humidity near 50% it is no surprise to me. We just deal with it
I have the same problem, and that's with normal humidity and dried filament. Prusament PETG at Stock 250°C prints absolutely awful, hat to go way down to 230 degrees to get reasonable (still not perfect) prints. I am using a plated copper nozzle though, and thought it was due to the better heat transfer. Anyway, i am not happy with how the Prusament PETG Prints on my MK3...
I had an interesting experience with PETG the other day. It was printing like doo doo and everything I tried didn't change it. So in desperation I turned up the hot end temp to 260. It started printing and was looking ok but the extruded PETG sounded like a bowl of rice crispys. You could see the the tiny bubbles in the layer lines. I figured the filament was trash because it was full of water and just let it print. After a little while the bubbles went away and the print looked smooth and glossy. I guess the take away from this is that if you think you filament is wet, crank up the temp and see if it bubbles. If it does, dry it out, and maybe save yourself a headache and a couple of dollars too.
@@gratefulamateur1393 That's what I figured afterwards. I thought this info might help some others with similar problems. Thanks for substantiating my theory.
i find if you follow the numbers printed on the rolls, I get the ideal finish, so long as everything is tuned up. i offer matte parts as opposed to glossy, and for the PETG i use 220C gets me matte and 240C gets me glossy. just the lower temp requires a slower feed rate to prevent under extrusion. bottom line, the most important research you can do, is on your own. working with the 1st layer or first 5 or so layers you can really dial in your feeds and speeds as well as the ideal temp for what you are going for, whether is "strong" parts, nice looking parts, quick and dirty, etc.
Great review, and plotting the values helped me understand the results better. I know that a lot of effort went into those charts, and it is appreciated.
8:07 I too prefer matte, but the tiny steppiness from marlin input shaping at low frequency has enabled me to print hotter as it also makes the finish more matte
The only question you didn't address is 'Are you really printing at the right temperature'? i.e what is the easiest or best way tell how accurately your thermistor is calibrated....
4:30 On that note. Do you guys know of any videos discussing printer head clearance setup and tips. It's extremely clunky and confusing the way it's implemented in Cura.
Btw you should really tweak for the brand (and sometimes color) of filament too. I have some white PLA that strings horribly at 220C and still strings a ton at 215C but works flawlessly at 210C.
Regarding DIMENSIONAL ISSUES with LOWER TEMPERATURE: I experienced, that for each temperature the pressure advance needed is differently. In fact, even the filament flow seems to have an impact on this. Meaning, even though you perfectly calibrated pressure advance, the more filament is pushed through the nozzle per time (=volumetric speed) the more under-extrusion you get. In fact, there seems to be a linear relationship between volumetric speed and volumetric-flow-% (effective flow-factor). Meaning: real_extrusion = (1 + factor * volumetric_speed) * extrusion_commanded. This factor effectively seems to be temperature related and not be be compensated for by the slicer or pressure advance.... HOWEVER, there seems to be a sweet spot in the temperature range, where this factor seems to is very low. -- RESULT: So when you calibrate your printer for a higher temperature (pressure advance and flow) and then print at a lower temperature, this results in over-extrusion... and hence parts that are larger in dimensions. I guess this is what happened here.
Realized with my V400 that the consistency in the performance of the hot end thermistor is degrading the more I increase the temp, which is why accurately controlling the actual temp of the nozzle is obviously affected. Perhaps this component of the printer system should be part of what is upgraded instead of being the low-cost performance part that comes standard. However, it may be a challenge to integrate a better component with the controller board. NTC(not PTC) thermistors are expected in 3D printers. Perhaps the real problem comes from the resistance in the thermistors not being linear in the temperature range, which leads to the question of the ideal(but perhaps unnecessary) of having different thermistors with more narrow temp intervals depending on what material is printed (i.e., PLA vs. ASA). This would ultimately lead to one printer modified in HW and not only SW settings for one specific material(or even brand on top of that), and another printer HW+SW modified for whatever other material needs to be printed.
I love these kind of videos. It'd be fun to see you print a bunch of different filaments, go over the challenges of them and do some stress tests. Love the videos keep em coming!
I am happy to see that the 215° that I print at for PLA is in fact the best option. Although I do have some silk PLA that clogs my printer unless I print it at 225°.
I did a nozzle change recently, and i realized 😂 I needed to print significantly hotter because the nozzle was “clogging” but really it just was t following good enough.
I tried my first roll of silk pla filament. The roll label said hot end temp 180-240. I very first went with 220 for a Oreo caddy. The printed subject on the bed appeared to have “bubbles”. After 20mins of a 11 hour I quit print. I started to print a temp tower at 220 first layer and same so I changed temp down to 210 and let it go few more mins. Not happy I gave up temporarily and packed roll away to try later
The PLA we use in Argentina (3N3) is printed at lower temperatures. 215 degrees is actually almost too much. We print at 195-210 degrees on this material.
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Wow, the impact graph is weird and not at all what I expected...
Engineering school was a long time ago for me, but does part cooling have an impact on brittleness as well? I recall from my materials science course that quenching metal rapidly made it harder but more brittle-also true for plastic?
hotter layers have more time to shrink within second after deposition. Same thing can be observed on curves sometimes, when some perimeters just shrink away leaving gap.
I print my South African SA Filament PETG at lower than recommended after numerous temp towers. I even had to abandon the manufacturers PETG temp tower range of 235 to 255C. I find it prints best in gloss at 210C. I thought it was pla except it is flexible like petg and won't stick to my glass bed unless I turn up the heat on the bed to 70C and 250C for the first layer. It's also really strong. It's supposed to be copper coloured (actually more like pot plant orange brown). The fan speed I am still tweeking. Zero on first layer and 40 to 70% on subsequent layers.
the only thing i can think of regarding the tolerance of the parts fitting into the jig is printing outside walls first or not. Beyond elephants foot I've noticed that printing from inside to outside can make a part fatter by.02-.3mm the other factors being the various temps involved and if enclosed or not.
It depends a lot on the speed too, prusas are slow and the filament is kept hotter for longer, on a fast printer higher temps just make flow possible without insane pressure buildups
I ponder if the used pigments alter the materials performance. Aluminium particles, being metal, absorbing more heat, darker colours heating in much faster versus transparent colours being slower.
Note that every brand PLA can have it's own ideal printing temperature, so you're better off doing some test prints yourself I think. Printing at 190 is not too low for some brands PLA..
im a total noob, got me a p1s and after two weeks i started to play around with temps.... standard setting is 220 , i turned it down just a lil bit to 217 and its alot better now... can it be a few degree make such a big difference??
Danke für die Aufklärung! I was trying around with different temperatures recently as well, but i ended up destroying All my results by switching way too often between PLA and PETG. This resulted is a big plug of solid filament in the cold section of my revo nozzle. What a pain in the b*** to remove that... Now i dedicate one Set of nozzles to PLA and one Set to PETG. At least this was something i learned during my Experiments.
I see someone mention thermal expansion/contraction as a possible reason for the thicker parts at lower temperatures (i.e. lower temps = less difference between the volume of plastic when it's hot vs. cold leading to slightly bigger parts). I would argue that wouldn't be the case due to the extrusion happening above the melt zone so, assuming all steps can complete, an equal amount would be extruded. However, I know that there might be skipped steps at lower temps. So it's even more counter-intuitive. That said, I wonder if die swell could be a factor? The more pressure you have to exert on a viscous plastic, the more die swell there might be? Just grasping at straws.
filaments tend to puff when printed too cold because of internal stresses, especially when printed with 0.6 nozzle. im 2 years late to tell that but here you go
Dude, I’ve got to say, your rate of improvement in English speaking/presentation is impressive. Your English has always been good, but you sound nearly native now. Your inflection patterns are indistinguishable from a native speaker. Any tips for a fellow language learner?
Can it be that the residual heat keeps plastic more sticky and the polymer chains have more time to form longer chains. And in the colder the chains get shorter. I think a trip in a heated chamber can be interesting to try. And you have so many variables that works here like residual heat in the heating block pid moisture, wind drafts, heating profiles.product variations , But still so good to see the result helps me figure out what's wrong with my prints. Keep up the good work.
I sort of missed out on the fan speed? Is that varied? I tend to print at higher temp for PETG, with like 70% fan speed. That improves bridging. Or at least, I think it does. At lower temps, there is a need for less fan speed on the cooling. Also, using a sock for a V6, the cooling fans is supposed to influence the hotend temp, as in actually not cooling the hot end as much. My point is, the other settings are not the same, if you vary the fan speed. The results will also vary insanely, correlating to print speed. I cannot print with that 70% cooling fan speed, at any high speed at all. Only snail speed. In my case, using a MK3, I prefer slow print speed, medium temp of 240C and fan at 70%, for PETG. If I were to change the temp, I would need to get to play with every setting again. Long post, but Thomas, I would love to get your input on what you think about fan cooling speed setting and print speed, for at given print temp for PETG. What to look for, as to increase print speed or not, and what effect the cooling fan would have. Then compare optimized results for each temp. Like PETG at 230, 240, and 250. There will be pros and cons all over the place, and there definitely will be something I have missed. Looking at the particular test in this video, I just go, "but I would never print like that". For lower temp, I would seriously decrease print speed and fan speed. Using a standard V6 with a sock, I tend to use higher temp and higher fan cooling, but that seriously disallows high print speeds, as in nothing sticks together at higher speeds, due to too much cooling an too poor of a heat end and the Nozzle X sure does not help in my case. (It cleans easily and lasts forever) Since I am rambling: Printing at a lower print speed, results in significant less wear on the printer. There is also far less noise. And if you care about noise, placing the printer on some IKEA plastic boxes made for storing food, just filled with sand, is insanely effective, and almost for free.
One important thing is the environment temperature. I print in 23°C environment without enclosure and my PLA Benchy is with PLA Polymaker at 205°C fantastic. My Voron with enclosure (doors are opend) I have around 30°C and my Benchy has overhangs. First I thought it's because the new mosquito hotend and wrong cooling geometry but I think it's because the environment temperature. So if you print don't forget the environment temperature for PLA
Have you tested the best temperatures with different materials of the nozzle? It seems a hardened steel nozzle requires higher temperatures as it has worse temperature transfer than a brazz nozzle.
I created a pressure petg cotton algae filter and the pressure reached 80psi pressure, there were small leaks I just super glued it and now it has no leaks. (I don't know if the pressure is correct, its the cutoff rating on the Chinese 12v Water Pressure Diaphragm Pump ) and I got the best layer adhesion on 250 degrees Celsius with full infill.
I generally tweak my print temperature from the baseline based on how much plastic I'm trying to shove out the nozzle. If I'm printing faster and/or thicker, I'll bump up the temp a little so my extruder doesn't start clicking. Conversely, if I'm printing slow and/or thin, I'll go down in temp a bit to keep from having that lovely cooked plastic smell.
It would be nice if the printers could adjust their speed to compensate for too much resistance. Some kind of strain gauge on the drive wheel, perhaps.
i'm interested on how temperature correlate to print speed since PETG actually prints better at 250c, it'd be interesting if using a non-high flow nozzle, whether you can push the flow rate higher
Should increase maximum flow. Once talked with a ender3 owner, she said, she cant print the pressure advance print for klipper, hotend cant keep up, told her to bump up the temperature, print was successful
If you use a lined hotend (PTFE inside) you get a clogg since deforming the PTFE at 250 degrees so resulting in slower printing after a short while. Been there, tested that out to find that out, so with those printers I stay only close to 240 degrees and printing a bit slower.
The thing about petgs resistance to outright breaking, is that, at least to anecdotal evidence, it picks up water similarly after as before a print. The reason this matters, is that this means when left 9ut petg always becomes brittle, kinda making it useless 97tside temp resistance.
The conclusion to me is that Prusa did a good job of testing their filaments on their hardware and setting appropriate defaults. Not a huge surprise and bravo for them doing that!
One aspect of temperature that you didn't cover in this video, but have in past ones: thermal expansion. The hotter you print, the more the plastic expands, and therefore contracts while cooling... This is one of the main factors in warping and necessitates a heated build chamber for certain materials. The low temps parts aren't shrinking as much and are tighter when put in the same hole as a part printed at a higher temp.
Also print speed is a huge factor in print temperature. The bottom line is heat transfer, how much heat is getting into the plastic, what that heat does, and how long it stays there. If I want stronger prints with better adhered layers, I print slower. If strength isn't a factor and I need a faster print, I turn up the temp with the speed.
What would you consider as slow printing? I can most certainly confirm that printing Cf nylon at 30mm/s is much weaker than printing the exact same part at 60mm/s. By printing faster, the lower layers are actually at a higher temperature thus improving bonding strength. You can take this further by printing at 60-80mm/s but at far higher temperatures than recommended. For example, I print Taulmans CF nylon at ~70mm/s at 280-285°C. They recommend 255-260°C. This makes the layer adhesion insanely strong and the part overall is leagues stronger and stiffer. The downside is supports will bond way too well and warping becomes a factor to be weary of.
@@FrozenByFire3 there's probably multiple ways to reach a certain result, with different downsides
I know im 2 years behind on this comment, but I am also finding that in some cases not cooling quickly enough with certain filaments (in my case polymaker polylite pla pro) Causes filament on overhands to curl upward due to still being too hot when the nozzle runs back over them and leaves them curled upwards. So in some cases cooling is very important, especially after the first few layers!
Cold prints getting stuck in the impact test jig: parts printed at lower temperatures likely shrink less after printing, resulting in larger parts and a tighter fit.
White PETG is always reliably bad for me, doesn’t matter the brand I’ve tried. Something about the pigment just makes it worse than every other color.
I agree I avoid white filaments
Had the same with white PLA. It was terrible so never again.
All white filaments are a hassle to me, no matter the polymer. PLA, PETG, ASA, ABS, TPU, no matter what, I need at least two prints to get acceptable results.
The "milky white" PETG I get from California Filaments has always printed fine for me. My guess is that they have less of the white pigment - hence the semi-translucent "milky" appearance. If you really want white in PETG, you might give that a try.
Do they just have to load it up too much with the TiO_2 powder to make PET look opaque enough?
For me, 10 ° under high number on filament spool has always worked well. Then bed pla 55 ° and Petg 85 °
Biggest fix I’ve learn for bed adhesion and avoiding fuzzy first lays with a PEI Flex sheet is just occasionally washing it in the sink under hot water with dawn dish detergent. Try this first when things go wrong all of the sudden. I learned this after days of settings chasing. Great video!
Thomas is getting more and more like Stefan. Won't be long before he CNC's a proper pull test jig.
I'd say the opposite is closer to the truth...
Yeah, but i find the charts that Stefan showed, very hard to read. Go-go Thomas!
Who is Stefan?
@@muffty1337 Another UA-cam 3D printer/CNC content creator (Channel is "CNC Kitchen"). Thomas and Stefan have Podcast together (Podcast is "The Melt Zone").
@@muffty1337 Stefan from CNC Kitchen.
honestly, temperature settings are something I set on a per-print basis. Things that I factor in are: Nozzle size, purpose of the print, room temperature, are there any large bridges etc.
I generally print PLA with 200-210 Celsius, a bit lower for 0.2 nozzle, about 220 with a 0.6/0.8 nozzle(those are mostly vasae mode prints where I want it to hold water and usually increase flow to about 110% ish)
what bed temperature?
Thank you Thomas for publishing a neat video in the middle of summer. So we can print at the right temperature. ❤❤❤❤❤
11:40 "I should note that the default temperature for Prusament PETG, on PrusaSlicer on a Prusa MK3 is 250 Prusa-degrees"
I know Prusa have printers and slicers but I didn't know they had their own units 😂
All the post-soviet 3d printing enthusiasts refer to "parrots", not degrees. This origins from an old cartoon scene with character measuring a big snakes body length with a parrot. Every printer reports temperature a bit off (most of them are Chinese here, so more prone to this behavior) so sharing what temperature you use is more "scientific" if you mention the units may vary this way:)
Most of the thermistors are manufacturered in China. Even on American and German 3D printers, so mostly their temperatures are the same as the Chinese ones. You can buy thermistors with different temperature tolerances. All from China. So it depends on what is installed and where exactly it is located in measurement. Also the thermistors are all rated at 25C but have different thermal constants. But the manufacturers are aware of what these are and choose them specifically. The possibility is manufacturers don't test a part to confirm the characteristic tolerance is within spec.
I have also noticed PLA having a tendency of printing less glossy, more matte at lower temperatures, which is why I tend to lower the temperature somewhat for decorative items; matte items just tend to look better than glossy. I haven't bothered increasing temperatures and instead just adjust infill and/or shells, if I need stronger parts -- I haven't done any proper measurements, but I haven't seen any benefit in increased temps.
@Benson Except your analogy is idiotic and doesn't work. One can e.g. perfectly well tell an improvement in acceleration even without a speedometer.
Watching this makes me glad I can create project profiles directly on my old faithful Ultimaker S3 dual nozzle printer (with NFC filament recognition) (auto levelling & heating). Using preset profiles that I found can include all known and customisable settings, making it easy for novices like me, to start at commercial grade printing qualities, without the hassle of knowing in advance what's required, just splice and load to get projects completed quickly, with a professional finish that requires little to no post processing.
Thanks for sharing your invaluable information. 👍
I got into printing a month ago by picking up an Ender 3 V2. Your high-quality videos have been immensely helpful. Keep up the great work!
It's been a year, but slap the Professional Firmware by mriscoc, it's a game changer and so nice
9:30 My guess would be, that there's a higher pressure build up in the nozzle, when you print colder.
And because of that pressure, the filament will bloat up more, when leaving the nozzle.
yup, was thinking the same thing. Lower temp = higher viscosity, which in turn results in higher extrusion pressures and increased die swell.
I would have thought slicers allocate for shrink, but too cold and the parts don't shrink to expected dimensions and end up slightly larger
@@erikwithaknotac Except that the user sets the Extrusion Multiplier so that the final extrusion width should match the value entered in the slicer for extrusion width, theoretically taking shrinkage out of the equation for the baseline. Also, for the lower temperatures, thermal expansion plays a much lower role than die swell for governing extrusion width (you can verify this by observing the relative change in line width with change in temperature vs change in extrusion speed).
I am assuming that Tom didn't change the EM settings for each temperature, but just used the stock setting for the entire run, which means that the main contributor to extrusion width is going to be die swell.
thank you so much, i always have problems with dimensions of my parts and tried everything to fix it. I will now test higher temp bc i have always printed at 195°
Thank you Thomas for a lot of work to do all these tests.
I'm glad you got back to the "old" tracks when you focused on the topic, not personal tours and sometimes strange opinions and comments.
There was a point where I saw too much irritation in your videos that pissed me off enough that I stopped following your channel.
Let's focus on the topic without intrusive private content. I appreciate you for that. And many others, probably too.
Regards.
Thanks for the test! I do appreciate the time it takes to print all those test samples =)
I usually found that "glittery" PLA prints way smoother welds at 225 compared to 215 that i actually found works best for run of the mill single color PLA.
Additives definitely skew the temperatures. Anything with an iridescent additive I crank up to 230, else it just falls apart.
Velocity affects surface gloss for PETG as well. If my print speeds are not constant, my prints are always banded with gloss and matte layers.
The trouble is, each printer and each brand of filament is going to be slightly different, meaning that really we still need to do at least some calibration with our printers and filaments no matter how much information we have. This testing, and other testing like it, definitely gives us a helping hand to get closer with less testing, but the testing will still be needed.
3 factors will impact your dimensional accuracy in regards to temperature.
1) shrink as the part cools
2) viscosity in the nozzle (pressures)
3) viscosity of extruded material, allowing more creep.
Each can be measured and calibrated to identify the cause, then correct.
You will need to adjust using a couple test prints.
I had to lower temperatures when used 0.2 nozzle. When print in low height rows standard 230C degrees with PETG result in deformations and stringing, so I use 220C instead. Which gave me decent quality on small detail.
i print pla in 210 and petg in 240 for me best results , i depends on few more things like temp alone in my experience. my printers stands in an enclosure and there i can slightly lower my temps
Good tips but in general it's simply easier to pick the highest temperature which allows bridges and overhangs to work well. It's usually very close to the optimal temperature, there's little to be gained by going higher.
Lower temp parts are overdimensioned because leaving the nozzle retaining the stress of a larger filament expand in XY and contracts in Z to retain its previous shape. Raising temps or using turbulent nozzles like CHT reduce the effect.
dud e why are you not changing the first layer temp, thats like the most important setting
I'm guessing the cold parts are coming out oversized due to die swell. Basically you have a greater temperature gradient as not all the plastic is coming out at the same level of "melted". This leads to internal stresses that can cause the filament to expand out of the nozzle
Bingo.
Thanks for the info...however in engineering terms, impact strength is different to tensile strength. Strength in printed parts with regards to heat and adhesion properties is always going to be governed by application needs. So, print variables should be practiced depending on application. No one setting is actually better than the next. That would be my conclusion. Thanks for the great and interesting content. Much appreciated.
If you print below temperature, you will have some solid and soft mix on the polymer, it will make it wiggle while it leaves the nozzle making the tolerances bigger
For cold extrusion temps, the filament is not entirely molten but soft enough to squeeze through the nozzle and then expands after it exits causing the layers to be thicker thus poorer tolerance. It may even be molten on the outside since that is the part of the filament in direct contact with the heater block but with a soft inner core not totally hitting the molten temp. You can see this with a zoom camera on the nozzle.
I'm currently using the Bambu Lab 3d printer P1S. It's an enclosed printer. I noticed that the smaller surface area I'm working with, the hotter I need to print, but I'm only heating up the bed from 35C to 55C. The biggest issue I believe I was having, was the Bambu default settings for the cooling fans is maxed out. My parts were flying off the bed.
Definitely going to take some time to learn the best settings for heating and cooling.
Thanks for doing science! I've just been printing PLA at the default setting of 200C, except bumping up the first layer to 205C for better bed adhesion at the cost of more elephant's foot. Maybe I need to do some testing myself to see if slightly higher temps would be better for the subsequent layers.
what do you set the bed temperature?
I found that my PETG and PLA prints were getting more and more matte the faster the printer was moving, and I wanted a more glossy and clean look so I increased the temperature as much as I could before the bridges started to sag and then I was able to reach much higher speeds without getting that matte finish. This I think means that the matte finish happens when your filament hasn't had enough time in the hot zone before getting pushed out, so I guess a volcano hotend would help if you print at lower temperatures at faster speeds.
Thanks for your contribution to this type of info. However, what about the affects of fan cooling on layer adhesion. For instance using 15% fan power vs 100% fan on PLA prints. I know personal experience shows this is definitely the case for PETG favoring 15% fan power and not much more for best layer adhesion.
Absolutely. I appreciate the time gone into the video. I just wish this was mentioned. Unless my layer times are low, I print with no fan for PETG to get max strength. It makes a huge difference especially with layer adhesion.
@@karlosss1868 Odd I have always printed with 100% and never noticed adhesion issues. I'll have to play with it now.
@@karlosss1868 I agree for max strength running petg with 0% fans. But If the print design needs some assistance for some fan cooling for bridging, it is always a balance of quality of overall shape yields vs strength in conjunction with overall quality of a parts intended purpose.
Probably something to do with exponential growth of the search space.
CNC kitchen has a great video on how cooling fan affects part strength. With PLA and PETG you can turn fan down alot but you must print your parts really slow. This will allow the layer to cool enough to not have bad print quality but you must be patient.
my elagoo fillament pla in black says 205 - 230 but a tempreture tower produces best results at 190c i do first layer at 200 but that is quite different to manufactures recommendation. in short print a temp tower on every new fillament batch thats what i do anyway
I've been printing PLA at 200° this whole time and was disappointed in my layer adhesion. THANK YOU!
The only confounding part: how accurate is each machine’s thermistor?
A good point. A test like this can give you a good sense of the general tendency, but you need to calibrate to your own machine in the end. My gut feel is that consumer machines probably vary enough that any two machines could easily be 5C different for the same indicated temperature. You could check build plates with a simple IR thermometer. But nozzle temp is a bit tougher.
@@wturber my ender 3 s1 bed was about 8° C lower than the temperature sensor reported before I redid the PID tuning and added insulation foam. Now its only 4°C colder than set.
@@twanheijkoop6753 I should actually test mine.
The larger dimensions on parts when printing below their optimal temperature can most likely be explained from non-uniform shrinking in relation to the printing temperature. I have long had the suspicion that shrinkage in 3D printed parts is non-lineair. Meaning that the hotter a print is or the more volume of plastic is deposited the more the part will shrink because of the disturbance in the polymer chains being more or less. Keep in mind that with 3D printing we're at the low-end of the liquid range of most plastics. PETG usually prints fine at 230C whilst I believe it's injection molded at close to 280C~ don't quote me on that, but I know from my own injection molding press that I cant get good shots at the same temp as the printing temp.
Long story short; 3D printed polymers, specifically FDM printed polymers most likely shrink more when printed at higher temperatures and less when printed at lower printing temperatures.
This could well show up in printing a tower at scaling temperatures during the print and the carefully measuring the print.
The mechanism behind it must have something to do with how to polymer chains crystallise. I'm not sure if the amorphous or crystalline nature of a polymer would matter or not.
I never printed matt filament, neither PETG nor PLA.
The matt-optics is the result of the filament filled with some stuff (chalk, talc, whatever) and it wears down the nozzle.
I’m not surprised that your results were bad.
thank you so much for that analysis, it will be really helpful for the improvement of my full 3D printed Bronco
09:30 Could it be that the material gets stressed from the high nozzle pressure buildup occuring when printing at too low temperatures, causing residual stresses in the material to cause something similar to die swell, messing up the final dimensions?
That's a good thought
It’s can also be because the parts shrink less than they do at regular temperatures. Those tenths of a mm could turn a loose fit into a pressfit.
The shear stress and resulting die swell you mentioned could also be a reason especially if Thomas printed the parts at the same speed-/ flow settings and only changed the temperatures for the parts.
He didn’t mention calibration for the different temperatures which could somewhat falsify the tests.
Yeah I think not fully melted polymer will have swelling around the extruder.
I second the pressure therory. I think the cause is the higher viscosity of the material at lower temperatures, resulting in more pressure against "itself", thus increasing layer width, because the other directions are constricted.
@@kkpal Die swell does increase at lower temperatures but that is only relevant when printing into free air. When laying down filament its width is determined by the volume per unit length over layer height. With the higher pressure at lower temperatures I would expect the hobbed drive to give a bit less filament, not more, so it is a mystery to me why the parts would get bigger. Perhaps bigger layer start zits due to the extra pressure.
Lower Temperatures at "higher speeds" means that the material is less viscous and as such the extrudate swell (die swell) is more severe which might have influence the tolerances. If you print them at lower speeds the impact test samples might fit better (potentially).
+1
Die swell from extrusion pressure being higher at lower temps?
I love the concept of sequential printing, but every time I try the first part comes out fine but the others have terrible first layer extrusion, like when you print without a skirt or staring line and there’s not enough filament in the nozzle at the start of the perimeters.
What about high temp for high speed?
I've defiantly experienced dimensional shifts when printing hotter. I'm pretty sure it has something to do with thermal expansion of the plastic while printing. Yes the mechanics are making the same moves and the extruder is pushing the same steps resulting in the same mass. (As others has mentioned pressure, mass would be something to look into.) But I think even with the same mass you can get different dimensions because hot parts will shrink more. Say a printer is accurately placing a 0.6mm line on the permitter of a part at 190c, when that part cools down to room temp it will have shrunken down to Xmm. Being less than 0.6mm. The same line *extruded to the same accuracy of 0.6mm* at say 230c, will shrink to Ymm at room temp. But Y will be less than X because Y had more temperature shrinkage, thus the part printed at 230 will have overall smaller dimensions.
Great video! Would be interesting to see (part of) the test repeated for fine tuning. So eg PLA at 209, 212, 215, 218, 221 or so.
Constructive criticism.. reconsider your force to break test methodology. The pipe used as a lever has a variable angle of incidence on the printed test part, when it appears you are trying to test vertical strength.. you are actually testing strength in a constantly changing Y and X vector. Rig up a pulley that is in between the luggage scale and your force input and you will constrain it to the Y axis.
I had to shake my head a bit about this test batch. Firstly, if I'm printing a part for which strength is a concern, you can darn well bet that I'm not going to print with two walls and 15% infill. That's the kind of setting I would use for generally non-functional parts that deal with little or no real stress. For strong parts, you really do often want your part to "pretend" that it is an injected molded part. Why? Because injection molding is expensive and sometimes you want a part to actually do useful work. I don't print my bike tire removal levers with two walls and 15% infill precisely because I'm going to subject them to high bending loads near the limits of the PETG material - much as your bending test does.
Secondly, you chose a matte PETG?!?!? Even if you didn't run into the semi predictable problems that you showed (I print a fair bit of matte black PETG because I really like the finish), I would never assume that a matte PETG filament would provide typical PETG results. In looking at matte PETG, it appears to have some kind of filler that gives it the matte finish. I don't know what that filler is, but I'm assuming that it does not increase structural strength and that it probably compromises it. I treat it as a different material than ordinary PETG. If I were to take this kind of time to do a test, I'd pick either ordinary colors that were the same for both materials, or neutral/no pigment colors. In this case, clear and "natural" for PETG and PLA respectively would be preferred. Doing this means you are testing the plastic and not the dyes or fillers.
I'm a fan of both Thomas and Stefan. But I found this test video a bit dumbfounding.
I think you misunderstood his explanation about the strength testing parts. He wasn't trying to test ways to make strong parts, he was trying to test the strength of typical printed parts using the most common settings of 2 walls and 15% infill. There are better ways to make strong parts than that. CNC kitchen did a great video on that, it's really most efficient to increase shell thickness.
On the second point, I think he was using the standard Prusament PETG that isn't a special matte finish. I had never heard of the matte finish specific PETG though, that sounds really interesting! Have you found the matte black to have significant mechanical weaknesses? That sounds kind of perfect for a project I've got going.
@@evanbarnes9984 I think you missed my point. People printing with only two walls generally aren't very concerned about strength. In situations where strength is any more than a passing issue, people print more and thicker walls - for the exact reasons the CNC Kitchen video outline. I'd also think that having more layers would be make for a statistically better test since with more layer lines, any unusually weaker line would have less relative influence on the results. Maybe his one "noisy" graph would have given better results if more layer lines were involved?
To be fair, his two 0.6mm lines are just as thick as three 0.4 mm lines.
As for the matte black PETG, I can't say for sure that it isn't as strong. My impression is that its "chalky" nature probably makes for weaker adhesion. But I've never actually tested if. I use the matte because I really like the look. In fact, it can look very nice when combined with the Cura "Fuzzy Skin" feature. If you'd like, I'll do some simple tests. In fact, I'll probably do it either way since this is something I'm a bit curious about myself.
As for the look of the filament, search for California Filaments. The have reviews online that often have photos. They also have matte in, I think four colors.
Thank you for these tests and your summary. Great information in the end and you answered a few questions I had in mind along the way.
Great to see that prusa has their temps in line! I do get pretty bad stringing with PETG at stock temps though, but I do think that is due to the swampy-ness of Florida more than anything else. Easy to clean up, but a bummer none the less! The impact strength is definitely an interesting one. Those variations could be from layer strength as well either yielding or snapping. Obviously a yield will absorb more than a snap? Not sure if there is correlation there.
Stringing is mostly from not enough cooling for PETG as I had a stock ender 5 pro did tests with it stock before I did the upgraded cooling mod huge difference and no more strings and can even print faster with the new cooling saving time.
@@Bigdog1787 I run mostly Prusas, cooling is not normally an issue. PETG is known to string as it gets a little bit moist. Having ambient humidity near 50% it is no surprise to me. We just deal with it
I have the same problem, and that's with normal humidity and dried filament. Prusament PETG at Stock 250°C prints absolutely awful, hat to go way down to 230 degrees to get reasonable (still not perfect) prints. I am using a plated copper nozzle though, and thought it was due to the better heat transfer. Anyway, i am not happy with how the Prusament PETG Prints on my MK3...
I had an interesting experience with PETG the other day. It was printing like doo doo and everything I tried didn't change it. So in desperation I turned up the hot end temp to 260. It started printing and was looking ok but the extruded PETG sounded like a bowl of rice crispys. You could see the the tiny bubbles in the layer lines. I figured the filament was trash because it was full of water and just let it print. After a little while the bubbles went away and the print looked smooth and glossy. I guess the take away from this is that if you think you filament is wet, crank up the temp and see if it bubbles. If it does, dry it out, and maybe save yourself a headache and a couple of dollars too.
The filament on the outside of the spool absorbs more water than filament inside the spool. Filament on the inside is blocked by outside filament.
@@gratefulamateur1393 That's what I figured afterwards. I thought this info might help some others with similar problems. Thanks for substantiating my theory.
i find if you follow the numbers printed on the rolls, I get the ideal finish, so long as everything is tuned up. i offer matte parts as opposed to glossy, and for the PETG i use 220C gets me matte and 240C gets me glossy. just the lower temp requires a slower feed rate to prevent under extrusion.
bottom line, the most important research you can do, is on your own. working with the 1st layer or first 5 or so layers you can really dial in your feeds and speeds as well as the ideal temp for what you are going for, whether is "strong" parts, nice looking parts, quick and dirty, etc.
What fan speed do you use.i use 0 for the 1st layer and then use 40 to 70% for subsequent. I am not sure what's est yet.
Great review, and plotting the values helped me understand the results better. I know that a lot of effort went into those charts, and it is appreciated.
8:07 I too prefer matte, but the tiny steppiness from marlin input shaping at low frequency has enabled me to print hotter as it also makes the finish more matte
I accidentally printed PLA at 260 yesterday, it looked fine but was rather brittle
The only question you didn't address is 'Are you really printing at the right temperature'? i.e what is the easiest or best way tell how accurately your thermistor is calibrated....
Is there a link to the Tom test board?
4:30 On that note. Do you guys know of any videos discussing printer head clearance setup and tips. It's extremely clunky and confusing the way it's implemented in Cura.
Btw you should really tweak for the brand (and sometimes color) of filament too. I have some white PLA that strings horribly at 220C and still strings a ton at 215C but works flawlessly at 210C.
Regarding DIMENSIONAL ISSUES with LOWER TEMPERATURE: I experienced, that for each temperature the pressure advance needed is differently. In fact, even the filament flow seems to have an impact on this. Meaning, even though you perfectly calibrated pressure advance, the more filament is pushed through the nozzle per time (=volumetric speed) the more under-extrusion you get. In fact, there seems to be a linear relationship between volumetric speed and volumetric-flow-% (effective flow-factor). Meaning: real_extrusion = (1 + factor * volumetric_speed) * extrusion_commanded. This factor effectively seems to be temperature related and not be be compensated for by the slicer or pressure advance.... HOWEVER, there seems to be a sweet spot in the temperature range, where this factor seems to is very low. -- RESULT: So when you calibrate your printer for a higher temperature (pressure advance and flow) and then print at a lower temperature, this results in over-extrusion... and hence parts that are larger in dimensions. I guess this is what happened here.
Realized with my V400 that the consistency in the performance of the hot end thermistor is degrading the more I increase the temp, which is why accurately controlling the actual temp of the nozzle is obviously affected. Perhaps this component of the printer system should be part of what is upgraded instead of being the low-cost performance part that comes standard. However, it may be a challenge to integrate a better component with the controller board. NTC(not PTC) thermistors are expected in 3D printers. Perhaps the real problem comes from the resistance in the thermistors not being linear in the temperature range, which leads to the question of the ideal(but perhaps unnecessary) of having different thermistors with more narrow temp intervals depending on what material is printed (i.e., PLA vs. ASA). This would ultimately lead to one printer modified in HW and not only SW settings for one specific material(or even brand on top of that), and another printer HW+SW modified for whatever other material needs to be printed.
I love these kind of videos. It'd be fun to see you print a bunch of different filaments, go over the challenges of them and do some stress tests. Love the videos keep em coming!
I am happy to see that the 215° that I print at for PLA is in fact the best option. Although I do have some silk PLA that clogs my printer unless I print it at 225°.
I was thinking I was running super hot when I was printing at 210 c for pla but you're telling me 215 c?
I did a nozzle change recently, and i realized 😂 I needed to print significantly hotter because the nozzle was “clogging” but really it just was t following good enough.
I tried my first roll of silk pla filament. The roll label said hot end temp 180-240. I very first went with 220 for a Oreo caddy. The printed subject on the bed appeared to have “bubbles”. After 20mins of a 11 hour I quit print. I started to print a temp tower at 220 first layer and same so I changed temp down to 210 and let it go few more mins. Not happy I gave up temporarily and packed roll away to try later
The PLA we use in Argentina (3N3) is printed at lower temperatures. 215 degrees is actually almost too much. We print at 195-210 degrees on this material.
Wow, the impact graph is weird and not at all what I expected...
Engineering school was a long time ago for me, but does part cooling have an impact on brittleness as well? I recall from my materials science course that quenching metal rapidly made it harder but more brittle-also true for plastic?
hotter layers have more time to shrink within second after deposition. Same thing can be observed on curves sometimes, when some perimeters just shrink away leaving gap.
I print my South African SA Filament PETG at lower than recommended after numerous temp towers. I even had to abandon the manufacturers PETG temp tower range of 235 to 255C. I find it prints best in gloss at 210C. I thought it was pla except it is flexible like petg and won't stick to my glass bed unless I turn up the heat on the bed to 70C and 250C for the first layer. It's also really strong. It's supposed to be copper coloured (actually more like pot plant orange brown). The fan speed I am still tweeking. Zero on first layer and 40 to 70% on subsequent layers.
That Segway to prusament filament. Slick thou... Best one this far 😂
bubbling/boiling off the moisture in the material is not hydrolysis. it just sounds fancy
the only thing i can think of regarding the tolerance of the parts fitting into the jig is printing outside walls first or not. Beyond elephants foot I've noticed that printing from inside to outside can make a part fatter by.02-.3mm the other factors being the various temps involved and if enclosed or not.
why is 0.6 the best size?? im kinda new
ua-cam.com/video/WgXM2zPusXo/v-deo.html
or this one:
ua-cam.com/video/nmigF5qyJ4M/v-deo.html
@@MadeWithLayers thank you for the reply and i will watch both :D
Thanks. I was going to ask the same thing.
i always printed my PLA at 190°C and was fine with it. Interesting results, will try out a bit more heat :D
It depends a lot on the speed too, prusas are slow and the filament is kept hotter for longer, on a fast printer higher temps just make flow possible without insane pressure buildups
I ponder if the used pigments alter the materials performance. Aluminium particles, being metal, absorbing more heat, darker colours heating in much faster versus transparent colours being slower.
Great video. I’ve been printing PLA at 190 and 200, which by your tests is waaaaaay to low of a temp.
I’ll modify my setting now! :)
Note that every brand PLA can have it's own ideal printing temperature, so you're better off doing some test prints yourself I think.
Printing at 190 is not too low for some brands PLA..
im a total noob, got me a p1s and after two weeks i started to play around with temps.... standard setting is 220 , i turned it down just a lil bit to 217 and its alot better now... can it be a few degree make such a big difference??
very informative, i appreciate your work taking the time to figure this all out
I would say it’s probably die swell that’s causing the parts to become too big at the lower temps
The bed adhesion graph was super interesting, going to change to 215 now.
Fantastic in depth video Tom. I'm a bit of a materials science nerd so this was very informative to me. Thanks!!!
Danke für die Aufklärung!
I was trying around with different temperatures recently as well, but i ended up destroying All my results by switching way too often between PLA and PETG. This resulted is a big plug of solid filament in the cold section of my revo nozzle. What a pain in the b*** to remove that...
Now i dedicate one Set of nozzles to PLA and one Set to PETG. At least this was something i learned during my Experiments.
I see someone mention thermal expansion/contraction as a possible reason for the thicker parts at lower temperatures (i.e. lower temps = less difference between the volume of plastic when it's hot vs. cold leading to slightly bigger parts). I would argue that wouldn't be the case due to the extrusion happening above the melt zone so, assuming all steps can complete, an equal amount would be extruded.
However, I know that there might be skipped steps at lower temps. So it's even more counter-intuitive.
That said, I wonder if die swell could be a factor? The more pressure you have to exert on a viscous plastic, the more die swell there might be? Just grasping at straws.
filaments tend to puff when printed too cold because of internal stresses, especially when printed with 0.6 nozzle. im 2 years late to tell that but here you go
cool that u used the charpy v notch test
Dude, I’ve got to say, your rate of improvement in English speaking/presentation is impressive. Your English has always been good, but you sound nearly native now. Your inflection patterns are indistinguishable from a native speaker. Any tips for a fellow language learner?
Can it be that the residual heat keeps plastic more sticky and the polymer chains have more time to form longer chains. And in the colder the chains get shorter. I think a trip in a heated chamber can be interesting to try. And you have so many variables that works here like residual heat in the heating block pid moisture, wind drafts, heating profiles.product variations , But still so good to see the result helps me figure out what's wrong with my prints. Keep up the good work.
Fantastic video Thomas. I will start printing at 215 I normally hover around 200. Great efforts 👍🏻Motters 🇬🇧
I sort of missed out on the fan speed? Is that varied? I tend to print at higher temp for PETG, with like 70% fan speed. That improves bridging. Or at least, I think it does. At lower temps, there is a need for less fan speed on the cooling. Also, using a sock for a V6, the cooling fans is supposed to influence the hotend temp, as in actually not cooling the hot end as much. My point is, the other settings are not the same, if you vary the fan speed. The results will also vary insanely, correlating to print speed. I cannot print with that 70% cooling fan speed, at any high speed at all. Only snail speed. In my case, using a MK3, I prefer slow print speed, medium temp of 240C and fan at 70%, for PETG. If I were to change the temp, I would need to get to play with every setting again.
Long post, but Thomas, I would love to get your input on what you think about fan cooling speed setting and print speed, for at given print temp for PETG. What to look for, as to increase print speed or not, and what effect the cooling fan would have. Then compare optimized results for each temp. Like PETG at 230, 240, and 250. There will be pros and cons all over the place, and there definitely will be something I have missed.
Looking at the particular test in this video, I just go, "but I would never print like that". For lower temp, I would seriously decrease print speed and fan speed. Using a standard V6 with a sock, I tend to use higher temp and higher fan cooling, but that seriously disallows high print speeds, as in nothing sticks together at higher speeds, due to too much cooling an too poor of a heat end and the Nozzle X sure does not help in my case. (It cleans easily and lasts forever)
Since I am rambling: Printing at a lower print speed, results in significant less wear on the printer. There is also far less noise. And if you care about noise, placing the printer on some IKEA plastic boxes made for storing food, just filled with sand, is insanely effective, and almost for free.
One important thing is the environment temperature. I print in 23°C environment without enclosure and my PLA Benchy is with PLA Polymaker at 205°C fantastic. My Voron with enclosure (doors are opend) I have around 30°C and my Benchy has overhangs. First I thought it's because the new mosquito hotend and wrong cooling geometry but I think it's because the environment temperature.
So if you print don't forget the environment temperature for PLA
Have you tested the best temperatures with different materials of the nozzle? It seems a hardened steel nozzle requires higher temperatures as it has worse temperature transfer than a brazz nozzle.
Do these test with a .8 or 1mm nozzle where the added temp helps a ton. I print at .6 layer heights at 235 for pla.
I created a pressure petg cotton algae filter and the pressure reached 80psi pressure, there were small leaks I just super glued it and now it has no leaks. (I don't know if the pressure is correct, its the cutoff rating on the Chinese 12v Water Pressure Diaphragm Pump ) and I got the best layer adhesion on 250 degrees Celsius with full infill.
I generally tweak my print temperature from the baseline based on how much plastic I'm trying to shove out the nozzle. If I'm printing faster and/or thicker, I'll bump up the temp a little so my extruder doesn't start clicking. Conversely, if I'm printing slow and/or thin, I'll go down in temp a bit to keep from having that lovely cooked plastic smell.
It would be nice if the printers could adjust their speed to compensate for too much resistance. Some kind of strain gauge on the drive wheel, perhaps.
Would be interested in seeing if additives and different PLA/PETG formulations changes this
K1 max 15min benchy boat 600mm/sec hyper pla+ 240c is flawless. So device makes a huge difference. I fine enclosures make the biggest difference.
i'm interested on how temperature correlate to print speed
since PETG actually prints better at 250c, it'd be interesting if using a non-high flow nozzle, whether you can push the flow rate higher
Should increase maximum flow. Once talked with a ender3 owner, she said, she cant print the pressure advance print for klipper, hotend cant keep up, told her to bump up the temperature, print was successful
250? It completely depends on your printer calibration and print speed...
If you use a lined hotend (PTFE inside) you get a clogg since deforming the PTFE at 250 degrees so resulting in slower printing after a short while.
Been there, tested that out to find that out, so with those printers I stay only close to 240 degrees and printing a bit slower.
@@elvinhaak yeah same, did that for my ender, though I've heard that speed benchy ppl went higher temperature for higher flowrate
The thing about petgs resistance to outright breaking, is that, at least to anecdotal evidence, it picks up water similarly after as before a print. The reason this matters, is that this means when left 9ut petg always becomes brittle, kinda making it useless 97tside temp resistance.
The conclusion to me is that Prusa did a good job of testing their filaments on their hardware and setting appropriate defaults. Not a huge surprise and bravo for them doing that!