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The biggest problem printing with TPU for me has been getting proper layer adhesion along the XY axis. Maybe I need to adjust line width, but for whatever reason the TPU bonds well along the vertical axis but not the horizontal. Any suggestions?
Hello stefan, Thank you for the nice and insightful video! I have a couple of suggestions to test based on my experience with TPE filaments: Temperature greatly changes stiffness of TPU. I have printed powepads for my EUC. at -20°c they shattered instantly from small impact. It was printed from purple transparent TPU from esun which gets to my second point/question: Does transparency or colour affect material properties? I also have parts printed from extrudr medium anthracite (grey), it still holds up fine. I have also noticed creeping issues with TPU. Even under small load they will slowly give up and permanently change form. I have noticed this from several different applications, biggest one was kickstand for EUC which made it unusable because it gave up on one side and will always flip to that side. It worked fine for couple of days until it started to give in. I printed thin PETG supports to fix that issue. That brings my fourth thought, would heat treatment (annealing)help with this issue, or are there TPU filaments that doesn't do that. (It also happens with PLA, you cannot print springs or compliant mechanism that are stored as momentarily "deformed state". It will slowly give in. Also side note: I have noticed PP, to have a considerable amount of friction compared to it's shore hardness. It is also really nice material.
I printed some inserts for a tablet holder from TPU. It was as easy as you said (bed adhesion is amazing - the brim I added was completely unnecessary) and I was blown away by the seemingly indestructible parts I got. However, they're not as soft as I had hoped. Most generic TPUs you can buy are 95A shore hardness, which is just too hard for the "rubbery" effect I was going for. I want to try 30D next. Overall an excellent video, the only thing I think not mentioned was price - unfortunately, TPEs are all quite expensive, with the softer ones easily going into the 80€/kg range.
One thing while printing flexible materials i learned the hard way is to also lower your non-print speeds when printing tall models. Bed slingers tend to cause quite a bit of wobbling and models can get misaligned
@@timgromeyer2061 No idea, sorry. I would assume that since with delta or corexy the model itself doesn't move in x or y direction the movement speed shouldn't matter. I mainly use bed slinger for my printing and this is the first time i encountered this sort of problem with any filament. I admit i was also bit greedy and wanted to cheap out on structure and some of the supports and adding some more mass to model made it a lot more stable.
The issue with bed slingers is not speed but acceleration. So you can keep print speed on "bed-axis" but drastically decrease acceleration. You could also reduce acceleration by height, so the total print time is even lower
<a href="#" class="seekto" data-time="262">4:22</a> "I can't really wrap my head around what to print with this" Oh I think you already know, judging by what's printing in the background. I'm sure Mrs. Stefan is quite pleased.
Someone in the Rat Rig Facebook group gave me great advice that really works: When the print finishes rather than tear it off the bed pour a little bit of isopropyl alcohol or similar around its edges. I had trouble with phone cases that kept getting deformed when pulled off the bed. This solved it completely. The alcohol gets under the print I think via some capilarry action and almost releases the print from the bed. The force needed to peel it off the bed is reduced to something that feels like 10% of what it was before. I have tried it with several TPUs that before tended to damage my powder coated PEI sheet and it works beautifully. With G10 smooth surface it works too but a bit slower. After getting it off the bed this way I just have to let it dry out the alcohol from its pores.
@@MartianMoon All my beds are flexible too, but especiall with relatively low height parts with big foorprint the printed part is sometimes more flexible than the bed 🙂. I buy the IPA in plastic bottle with a tiny opening on top so it is easy to squirt a thin stream of it around the base of the print too.
@BaghaShams for textured PEI and G10 I know for sure it does. I never use glue stick. I am guessing that for smooth PEI it works also without gluestick but I don't have one to test it.
My favorite use for TPE is printing gaskets, though I'd really like some purpose-built ultra-soft filament with excellent chemical resistance specifically designed for it.
Prusa has a table with many materials and brands on their site that is really simple and intuitive. I’ve used it a couple of times to check the best brand and material for some of my projects :)
I legit allways use TPU when possible. It is basically indesctrucable ! And The Layer adhesion is sooo good. I have 2 Waterbottle holders for my bike printed in TPU, every other material cracked after a while cause of the impacts of the full waterbottle but the tpu one still works just fine!!
Can you recommend some very hard TPE ? I have some TPU over here but it's very soft and hard to print on my ender 3 with Bowden drive. I don't know the shore hardness. I don't even know the brand.
@@Saeschboy You can just buy hard TPU, most is quite flexible, but some sell multiple varieties, including hard ones. Basically indestructable to hard forces.
@@tarakivu8861It's a shame the hard TPUs are so expensive though. Anything above 95A is ridiculous. There is 64D and 74D hardness TPU available which sounds incredibly useful but it's like $1 per gram.
I actually slightly oil the bed for TPU: Put a drop on the PEI and distribute it. Then wipe it off with a dry cloth. Works great for me. (I use some fine mechanics oil.)
... and Every Bourbon is a whiskey, but definitely not every whiskey is a bourbon! The maximum volumetric speed was one of the best discoveries that I've made in 4 years of printing.
The current best use for TPU for me personally has been airsoft and cosplay, TPU is fantastic for Absorbing BB's in armor. And the flexability make it super nice to wear aswell
The flexible filaments can be used to print replacement covers for electronic equipment. For examples, the little "hatches" on cameras that cover the HDMI, phone, mic... plugs. These parts are often not available (especially with older cameras) and so worth printing.
<a href="#" class="seekto" data-time="1074">17:54</a> That moment of inertia formula that you used, works for rigid bodies. For a pipe it's only relevant for determining its resistance to buckling, but for comparing the overall stiffness of the pipe you'd want to use a formula where you take the area times the distance to the centroid axis.
So much information-and work to get this all together for us in a highly organized package. You're the best! (Aside: I've had the Recreus 60A for I think two ears now and I still haven’t decided what to print with it!)
I have a small home based business that 3D prints TPU products, so I appreciated this flexible filament video. I'm an engineer so I always like Stefan's data driven approach. I know from past CNC Kitchen videos that I can't get most of these filaments in the US but I appreciate the links to the filaments. I need a more energy absorbing material for a product that hasn't been converted to 3D printing and I need to try the foaming TPU but it's never in stock.
Even through a bowden tube I find myself using more retraction than is ever recommend for tpu. I like to use the purple glue stick because of the PVA in it. Drying the filament makes the biggest difference! Another really good TPU is the Ninjatek Armadillo. It's tough as shit, and you can print it faster. It has great industrial applications, and I feel it's being slept on.
your friction tests...the surface finish of the sample has a huge effect on how "sticky" it is, resistant to forward motion. So then the same material but printed with a smooth vs textured surface will perform quite differently. To add complication they will perform differently in wet vs dry conditions. The supersoft material likely deformed during the test, creating more surface area in contact with the ground surface.
Also the coefficient for sliding friction will never ever exceed static friction. There is no other way except there being loose particles building up while sliding adding up to the drag
I'm surprised that this video never mentioned flexible PLA. I've become a fan over the last few months, it's so nice that it adheres well to regular PLA. I recommend checking it out.
@@robertd330 I use Flashforge. I use the exact same settings as for my normal Polymaker PLA but I slow down to either 1-2 cubic mm/s or 15-20 linear mm/s with similar results. That's just with a Prusa Mini, so you could probably go faster safely with a different printer. Basically, I just treat it as a color change and then use a modifier to slow down the speed for combined material prints. For all-flex prints I go the volumetric route.
I love that you did this. TPU (and TPEs) are some of my favorite materials (I have from 70A to 75D filaments). Depending on what I need it for, I sometimes don't bother with drying. Drying gives better surface finish, less strings, and probably better layer adhesion... but if all I need is for something squishy, then it's not as important. I've used it for HULA, phone cases, bumpers on rolling tables, wheels on vehicles, kids toys (seriously, all of you printing Toys for Tots and kids toys in PLA and PETG and ABS... print them in TPU instead. They'll be virtually indestructible, make less noise when they impact the ground, extra walls or higher shore hardness means you can make "non flexible" toys out of flexible materials and not damage walls, floors, etc.). I even had a vacuum sealer that had a custom attachment... I designed and printed an adapter out of TPU so it could be used with the standard circular vacuum seal points on generic vacuum bags, and one model I plan to print soon says to print the o-rings to make it water tight in TPU. It can do a lot, and certain brands come in WAY more colors then the 2-5 that many other brands have. May be a case of "US vs. EU" but I feel like the OG king of flexibles was missing: NinjaFlex. And on top of that, one of the most popular filaments, PolyMaker, also has a whole collection of flexibles. Many PLAs start as NatureWorks PLA resin 3D850 or similar, but I can't say "use one TPU, and you've used them all" so would love to see some of the big brands rather then just the EU brands. Outside of that, only real missing item: print on a textured sheet and you can skip the gluestick. It still sticks strongly, but you can peal it off without damage. The airless basketball has been such an interesting one to me... when everyone was going nuts over them, they used PLA. Before seeing the first full video on it, I went "it will bounce at least once... and then crack because PLA doesn't like impacts". And many learned that. PETG (more flexible then PLA and ABS), ABS, they all did this in the end. Finally, someone did TPU... I went "wait, why did you use 95A? That's gonna hit the ground and squish" and it did. I didn't have much reference point on bounciness, so I opted for a 75D TPU so it would be stiff enough to rebound... but still be flexible enough to handle the impact. 100% scale on the XL. It lasted well, some 12 bounces or so... then I tried it on a driveway and it bounced twice. The 2nd bounce, it caught a rock and that little extra bit broke the fine mesh of the ball and it cracked. So while people went all over the materials, the real interest was seeing the 3D models... the one you printed (PartyLime) seems to have done the best "reproduce the design with double lattice structure" that gives it some strength and ability to rebound where as many others basically just made a hollow ball with holes. Actually, looking at it... he apparently released a version and worked with a filament maker to make one with near identical bouncing and supposedly tested it on a court, which is impressive on how far it's come. $2500 vs. $60 and the will power of 3D printing community.
Used TPU to 3D print a door stop. I was looking at all the poor designs and lamenting spending $5 to $10 on crappy commercial one made of rubber that I had already seen fail. So I designed and printed some. The other benefit is that it can be easily modified for larger gaps or heavier doors. They work well out of TPU, and cost me literal pennies to make.
If you despise glue stick like myself you can try spraying IPA on the plate while removing the print or heating the bed to 100C before detaching it - both methods work for me almost always.
A lot of combat robots nowadays use TPU as armor, it'd be interesting to see how different TPE materials could be used in that application, resisting cutting and tearing
I can’t speak to combat robots, but I print all my racing drone mounts out of TPU and it can survive hitting trees and PVC at 80+mph all day. I’ll break multiple carbon fiber arms before my camera mount starts to split.
Im glad you tested coff of friction, up until now i would print tpu and coat it in plasti dip, but now i know what tpe to try for application where i need friction. Thanks!
I've been printing Sunlu TPU 95a at 11 mm3/s. I've never had much issues with it, but if I'm printing more than one part on the build plate it will string quite a lot.
We use TPU for motor mounts on one of our RC plane kits. The plane is used for full contact combat. I have never had a motor mount break.... yet. Thank you for this great video. Gives me more to think about for future R&D.
@@rm4po4 It's amazing when you get 10 airplanes in the air at one time. It's best if we focus on flying in formation first and then try to make contact. Otherwise it becomes a big ball of nothing for 5-10 minutes.
Great video! I 3D print nosecones for my model rockets. Double wall, 5% triangle infill. Creality CR-TPU. Not much bounce. But I want it to survive the landing. And it accepts paint!
I print directly out of a dryer for all filaments due to my short story... My first roll of TPU was Creality green. I printed with it on an Ender V2 and didn’t have great results. I learned about drying and used a dehydrate function on my air dryer to dry. Prints would start great then fail halfway. Long story short, It absorbed moisture so fast I could dry for 8 hours and within 2 hours it was bubbling again. I threw away about half a roll of TPU because I couldn’t get it to print reliably on 3 different printers. I changed TPU brands and now I have nothing but great results.
I didn't know about that max volumetric setting. That tip alone was worth the watch. I print a lot of engineering grade stuff like nylon and asa, and it really helps to slow the prints down, so I will be using that a lot now. It helps prevent thermal runaways, gives better layer adhesion and dramatically improves the print quality. It even helps with stuff like printing round holes in a perpendicular orientation (they come out more round and less squished looking). I avoid overhangs like the plague because the part cooling fan loves to induce thermal runaways at high nozzle temps, but I would assume it would also help with overhangs and bridging. Probably also help with making supports easier to remove with tricky filaments that don't like supports, like nylon. It's actually interesting how much of this video applies to nylon just as well as to TPU. Right down to the gluestick lol. I actually have really really good results printing nylon on the Prusa satin sheet with a little gluestick rubbed on with IPA. I wonder if that would also work for TPU?
I have printed TPU stuff on an Ender 6 with half a meter Bowden and TPU that's been laying in the basement open for a year.. yet to have issues. Probably just dumb luck. Extrudr Flex Hard was no issues..
Bowden Ender 3, I can print TPU without issues, but if it's undried it spits and blobs. It's awful wet, get it dry and it's acceptable. Now moved to a direct drive neptune 4 plus and it's night and day. Lovely prints but still needs drying in the UK before use.
I've found that when printing TPU in an enclosure, larger retraction numbers leads to a loss in print quality, and sometimes a jammed extruder. My theory is that over long periods the extruder heat break starts to get hot because of the high ambient temperature in the enclosure, this leads to the TPU getting soft in the heat break and therefore leads to filament jams because it's just stretching vs. actually retracting, aka just acting like a spring. I've found small retraction numbers work better. If you have stringing or bubbling it's most likely your printing temperature is too high, or the filament is wet. Limiting the volumetric flow just like you've mentioned is key. You might say just open the doors on the enclosure, but I've found there are advantages of printing at a higher ambient temperature, including a reduction in shrinking.
I print TPU quite a bit, and I have a bowden extruder, I've also never needed to dry the filament, despite living on the coast in England. You do need to print a bit slower, you do need to look at retraction and you do need to get the temperature right. Strangely I find 225c is usually fine.
Please dont print stuff like that and use it.. there are a ton of chemicals in there you def. dont want your body to take in.. If you really want to get into it, buy some Platinum grade Silicone (quite expensive), mold seperation spray (wax based should be fine) and 3d print your mold, maybe something like PBT to smooth it. You want it smooth, so nothing grows in the fine spaces between the print lines. For coloring, you can use Cosmetic grade mica powder, make sure its fine enough so it doesnt cut itself out of the silicone.
That material mike be idea for printing 'skins' for prosthetic limbs like the Hero Arms. Then get them painted with details to match the wearers skin tone and freckles and the like. It should also be easy to use to make the base shapes for film and TV effects make up pieces, such as Elf/Vulcan ears, Hellboy horn stubs or Twi'lek Lekku for CosPlay, or tentacles for live action Anime.
I have a Flsun Super Racer, and for those who know it, they will understand that it is difficult to print with TPU (95A shore) because it has a really long bowden tube. However, I managed to create a profile on Cura that allows me to always get "good prints," at the expense of a bit of stringing. The main problem I faced was the retraction speed. I spent days adjusting that value, but nothing seemed to work. So, I solved it simply by removing the retraction. To compensate for the stringing that forms, I raised the Z-hop speed to 200 mm/s and the travel movements to 350 mm/s, thereby reducing the probability of stringing. As for the brand of filament for the TPU, I used ZIRO.
I've had good results with a similar approach. Completely drying filament on the spool takes forever. Placing the filament in a dryer I can print from and drying for an hour or so and then starting the print while the dryer continues to run has made for a time saving process. I use the two Sunlu boxes shown in the video this way.
@@fabianmerki4222 It depends a lot on the climate/humidity. I have 50-60% and higher air humidity almost all the time, so I need to dry filaments a lot. Surprisingly, PLA needs less drying for a good print; and TPU - the softer it is the more drying it needs. Up to 6-7 hours. For my softest TPU I sometimes respool 100-200g of it and dry it separately right before printing - only this way it works...
I have used common 95A TPU on many items. Never have done any drying and my results are good. Stringing does occur but I am usually using TPU for less complex designs where there is not a lot of stringing and removing it is not a big deal. Regarding adhering to my textured PEI bed I just use no heating on the bed and removal is not that bad. I typically use TPU as a shell to install over a PLA case for impact resistance.
I don't have a filament dryer (or heated drybox), but with my regular airtight storage bin with desiccant I am able to successfully dry my TPU by placing the whole box where the sun would hit it by a south-facing window. I just use a cheap 2-pound pack of color-indicating silica gel beads, and recharge them after the first day or two. It takes a bit of forethought, but after 3-4 days it prints like a dream. This will be faster in warm climates, but up in the chilly midwest it takes a bit of patience!
I had printed TPU before ( maybe too wet as I learned right now ) and the results were acceptable. Lately I switched to a 0.3mm nozzle and I just tried to print my TPU again with a total failure. So I learned the hard way not to print TPU with a 0.3mm nozzle but that gives a hint to try it with a 0,6mm - maybe this gives even better results. Thanks a lot for your very interesting video !
Softness vs grip. That one can be explained by physics easily. The softer the material, the more "squish" it has, thus if it squishes, its surface or contact area becomes bigger and offers more grip or traction, exactly like in racing, where when maximizing grip, people will oftern take air OUT of the tire to have it conform easier to whatever it's sitting on and having a bigger contact patch since it squishes more with less aire pressure. Also on a second part of the answer, the softer the material, the more it will deform and give before actually moving. On top of that, the bounce back after finally having deformed as much as it could before moving releases the energy towards the pull direction and can create a braking effect making it harder to actually move it since it is now fighting back against the pull force, thus possibly explaining also why at some point it requires more force to keep it moving that actaully getting it to initially move. If all this happens on a very short timeframe (think bouncing back and forth many times a second due to it constantly being pulled) then basically you're releasing and ressetting that braking effect without really seeing it occur.
One of the best investments I made for 3d printing, was dedicated filament dryers for machines. Its made printing things like TPU, and Nylons a extremely reliable process. I live in an area with an average humidity of 95%. Air conditioning is also not common. So Not only do i dry my filament before printing. But I run the dryers while printing (requires a bit of thermal tweaking on filament profiles for temp based on time and flowrate). When printing TPE's at 0.04mm layer heights and a 0.2mm nozzle, you can see a noticeable difference when you hit areas that have high humidity, as it causes the dark filaments to cloud and lighten.
On smooth PEI you definitely need a release agent but I find that it's not a problem on textured sheets, and print on them with no additives. Adhesion is strong but not dangerously so. But do a quick test in a corner before you risk ruining your sheet!
I love flexibles. The results are so strong and have lots of uses. I've made replacement feet for an aluminium work platform where the original feet had gone brtittle and broken. Also made Shimano hydraulic brake bleed nipple covers, the originals are really soft and easy to lose when cleaning the bike, the TPU ones are bright green and look cool and are easy to find. We've used it at work to make masking covers for PCB connectors on boards that need conformal coating, much quicker to fit than masking tape, more precise and easy to remove
What's your go to hard TPU? Used to be able to get decently priced 70D from KVP but they don't appear to make it anymore. Ninjaflex Armadillo gets too rich for my blood pretty quick.....
@@ThantiK So much easier to print than nylon/pc/whatever technical filament you got. Someone should ask/beg Polymaker-Prusa-Greengate-Inland-Sunlu-ESun to mass produce the stuff. I've made gears out of 70D TPU that are stronger and more resiliant than the original injection molded stuff. Why can't we have nice things? lol
@@richardbertacchi5016 New to 3d printing here, but isnt nylon a better choice for gears because of its self lubricating nature and higher temperature resistance?
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@@xavy_ harder to print, but probably yes. I don't have an enclosed printer.
You could use it for RC car chassis, ship hull, or plane wing. Set it to be strong enough to take the lift and air resistance, but soft enough to not break if you crash. If it can withstand fuel, like gasoline, you could store fuel in the wings like real planes, and integrate the fuel tank into the chassis to save space
I designed a 3d-printable Ankle/Foot orthosis (FIDIM) for use with Nylon. That works great, but I've always been extremely impressed with the durability of TPU materials. The hinges on FIDIM are made from it. I'd really like to try a stiffer TPU for these now.
Well idealized/simplified physics about friction always start with the declaration: for rigid bodies and smooth surfaces. That is why your "anomalies" showed up. For flexible materials friction coefficients are not static. Think of temperatures affecting tyres or how their deformation changes how much friction they have. Try a much heavier weight and you should be getting higher friction coefficient.
I use PEBA a lot. I used to use TPU95A or 98A, but I found PEBA to be even better. My application is parts for FPV drones - they take a LOT of physical abuse (eg flying into solid object at 50MPH) It keeps it's elasticity down to a lower temperature. It bonds well with Nylon - an inner core of Nylon and an outer coating of PEBA is insanely durable and still quite rigid It's lighter than TPU
For TPU, I disabled retraction. I print with 30 C bed heat. I also had great success printing at 230 C. I came by the 230 C by manually pushing the filament while heating and picking a number 10 C above that. The on spool recommendations seemed very high to me given that TPU liquifies at a lower temp.
What i learned since i startet 3D-printing TPU nearly 23 years ago is to put some gluestick on the printplate. Since then i am able to reconnect all TPU / TPE parts. This also works great with glas printplate to not chip them (allways a problem with ULTIMAKER)
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You can also measure the static coefficient of friction by putting the material on an inclined plane, and increasing the inclination angle until it starts sliding. You can easily measure the coefficient of friction from the angle: f = tan(angle).
I built a heated chamber around my super cheap printer. The spool holder is in the chamber. I usually set the temp to the drying temp of the filament as that is usually a good temp to prevent warping. Then I just store the filament in desiccant box. Never have to worry about drying. Just used some cheap parts like a heat gun and some purple foam from HD for the chamber. Put the electronics outside the chamber....flexibles are probably my favorite filaments because the layers bond so well And I never have to worry about the part breaking.
For flexibles, I have so many tiny spots where filaments can grab. So, I have to decrease the retraction distance, but usually increase the retract speed to get it out of the way fast. And otherwise avoid retractions when possible.
I am really in love with my EIBOS Series X: Easdry Filament Dryer. It is super cheap (50$ including Shipping) it is small, can be directly printed from. Has a fresh air fan (so actually is able to remove moisture) and is quiet. I print directly from it, so drying is only required for 1h or so and while printing. Perfect results!
If you don't use glue, try pouring some isopropyl alcohol on the print once done. It reduces the strength of the bed bond after printing by 90% and it makes it easy to peel off. :)
few key takeaways when I do my tpu tuning, I'm not sure about it's shore hardness but I first tested the vol flow by extruding at a set speed, resulting in 5mm³/s, set that in the slicer, the. proceeding to flow, pressure advance, then retraction, finally got my pa to 0.32, flow rate 1.0, retraction 0.9mm at 30mm/s and yeah, having tpu dry is REALLY crucial to get a successful print!
You should do a video with that guy that made the flexible rubber toy that jumps up when you turn it inside out because he found films that were way closer to real rubbers and silicones than anything I’ve ever seen
Experience: I found a video (from uncle Jessie "Can you 3D Print your own $2,500 Airless Basketball?" for printing balls with overture super pla+. I tried it and it was so worst print experience ever. It warps like ABS without enclosing. I tried to print gears - unuseable. Maybe you will try it for your bouncing experiments. But I like to use TPUs - never had problems printing it at about 60-70mm/s (Ender 3S1) - and yes, keep them dry! The filament dryers are garbage, they do not release the wet air and replace it with fresh cold (and dry in abs. humidity). I store them in cereal box with humidity meter and replace desecant if display goes over 20%.
Hello Stefan, can you make a video on the subject of fine dust and 3D printing, as well as the vapors when printing ABS/ASA and how best to deal with them?
When using glue stick, I mix in a few drops of water after applying the glues stick. When the water/glue is about the consistency of paint, I lay the bed flat and let it dry. The result is the glue surface is flat and smooth.
I had an old printer that printed TPU with no issues. My newer one always jams. Both are direct drive. But you got me thinking about retraction. I need to check that. The filament I'm trying to use is really flexible, and seems to be jamming at the gears. Maybe trying less retraction would be a good idea. I stopped using ZHop completely on TPU and it helps with stringing quite a bit. Also helps on PETG for the same reasons.
I keep my filaments in plastic boxes with plenty of silica gel on bottom. (dirt cheap if you buy the kitty litter quality in large bags). I have a kind of bowden style tubes for filament takeoff. I mount the selected ptfe tube close to printer and the rest of tubes loop back to a quick link connector on box. Any large enough box will do and some tubing can be mounted to hold several rolls in a row. Food drier and/or vacuum are some methods I've used to dry other filament. After they are dry, they keep dry and print from the box.
The materials aren't dangerous to you since the fibers are embedded in the plastic and will not magically leave it unless you burn the plastic away. How safe these fibers are depends on the diameter of the fibers. I don't know about other countries, but here in Europe most commodity plastic manufacturers have switched to fiber diameters that are considered harmless for workplace safety reasons.
Thanks for the video! In particular, thanks for the range you give for Max Volumetric Speeds. This will come in handy as I start experimenting w/ softer tpu / tpe.
I have a pretty old roll of Sunlu TPU (95A according to their website), and it prints OK on my Anycubic Mega-S (bowden machine). Only storing it in a normal drybox together with my other filaments, and so far I had no big issues with moisture. Just checked my profile (which is a slight adjustment of the default Anycubic "flex" profile in PrusaSlicer), and it's set to only 1.2mm³/s volumetric speed, so that explains why the prints are VERY slow. But hey, I can live with that since I mostly just print small stuff like bumpers or connector caps in TPU.
I have already printed a lot with TPU 95A and TPU 60A on my Ender 3 Pro. And yes it is with bowden extruder setup (and a Phaetus Dragon hotend). I printed gaskets, some boxes for tools and dampening feet This video comes just at the right time for me because I want to try new flexible materials. Your tests were very helpful to learn about the properties of TPE's from different manufacturers. Have you ever tried SBS filament? SBS schould be a bit more grippy. I would like to test SBS, but have not yet been able to find a supplier in the EU.
Most important thing I learned is keep my family away from my printers, machines, and all my gear. Also learned that some people will not learn and would rather remain ignorant, which is why I have choose to adopt myself. :)
I love TPU 95, prints very well on my old direct drive upgraded Ender 3 and the parts are nearly indestructible. One of the best functional printing materials for durable parts if great stiffness is not required and of course great for parts where flexibility is desired like plugs, seals, protective covers, bumpers etc. I have not yet tried the more flexible materials but I would like to when I have the time.
Thank you for finally explaining something, I've never had to dry my filaments to get reasonable surface finish, even my black TPU. I guess it's because I print my filaments at the lower temps. Usually 220C for a roll I have sitting out in 30-60% humidity..
I've actually had success printing 95A TPU at 12 mm3/s on my slightly modified Sovol SV04 with titan extruder. The main modification was drilling out the metal filament path between the extruder gears and the heatbreak - and instead adding a short bowden tube there - almost touching the extruder gears and down to the input in the heat break. So, the filament has nowhere to bend and escape the filament path.
I tried the Tianse TPU. Printed beer cozies, and various vase mode boxes and statues. I think I struggled a lot to get it to stick, and/or stick too much, as I started using glue sticks. Still have a few spools.
My volumetric flow for Ninja Flex (85a) is 6mm/s³. That's with an extruder and hotend combo I designed specifically for TPU on a highly modified Ender 3V2. It's my printer for flexibles while my Vorons and Bambu do everything else. As for bed adhesion, no glue or anything on a textured surface and I have no issues. The trick, set your end Gcode to set you bed temp for 80c. Having the bed heated up significantly increases the ease of getting TPU prints off the bed.
Still printing flexible filaments with my trusty old cr 10 mini since years. The only modifications to the printer are a dual gear metal extruder with a hand made guide to prevent escaping of the filament while getting pushed, a bed level sensor and a Buildtak surface on spring steel. And yes still using the Bowden setup, no direct extruder. I am able to print soft TPUs like Ninjaflex with it. Just going very slow.
Hi there. Your Setup for the friction test does not work for flexible materials. In addition to the force to overcome the friction, you will use a part of your measured force to elongate the flex material, so your measured force will include friction and elongation (yo can already see the deformation with the softer stuff in your video). That would also explain your abnormal behavior with the greater sliding friction. A better setup would be a simple ramp with adjustable slope. Put your material with some weight on the ramp and increase the slope until it starts moving. From the slope you can calculate your friction coefficient. At least the static friction coefficient should be measurable with this.
When you have a part stuck to your bed, try spraying around it with some isopropanol, just be aware of the fire risk, my theory is it wicks between the part and the bed and then evaporates breaking the bond.
Instead of glue, you can reduce first layer temperature to avoid bonding to bed surface. In general you should stay below 230C on first layer and there will be no problem with too much adhesion
One thing I'd like to know is which is best at rebounding after a long term of compression and which "learns" the new shape and doesn't return to original.
I haven't found much info on TPE filaments, so bought some from 3DPrintingCanada. The soft rubber feel is similar to overmolding grips in consumer products, really neat. I noticed a significant difference in friction coefficient when comparing tpu and a rubber-like tpe, where the tpe had much better grip with the same hardness. Lastly, couldn't get my prints to stick to a textured pei bed using tpe. Tried several different tapes, but finally tried packing tape and worked perfectly! 40C bed. Parts stick very well, are still simple to remove, and the tape comes off easily because of the low bed temperature. I've had good success setting retraction to zero, and minimizing travel movements to the absolute minimum. Use more walls/concentric infill for top/bottom to avoid those pesky gaps in rectilinear. Makes for some very well filled in parts :)
I'm using tent for my printer and discovered that when tpu is in the tent - it's getting too soft on the roll and often ends in problems, but when filament is in cool room its printing perfect (and im using boden ender so it should not be possible), so it's not only printer settings itself :) I would not recommend printing from dryer because of that
I’ve only just recently started in the 3d printing hobby. Channels like Your’s Made with Layers’ and Z. Freedman’s are not only my go to resources when I hit a wall but you guys set the standard for Making, 3D Printing, ECE and how they’re all connected. Being a rookie, I learned the hard way about moisture, I’m working on sourcing some dedicated filament dryers. In the mean time, I have a food dehydrator. I’ve seen one a few times in your videos. Will a food dehydrator actually do the job? If you have a video on that specifically, please point me in that direction. Thanks for the video and your time.
I use an electric skillet set at its lowest setting filled with rice or beans (uncooked, of course) and then i sit my cereal boxes slightly buried in the rice and cover the whole thing with a big enough box box. this way the rice acts as a heat buffer. No airflow whatsoever, but it is still good enough to reduce low levels of moisture. i also put my cereal boxes inside of my car on hot sunny days. again..not as effective since there is no airflow, and a really sunny day could potentially ruin PLA, but it is also a very good option.
I had some fun doing speedbenchys with my 70A recreus Filament. I got down to around 15 minutes, but for that i had to print at 280C which didnt smell too great. But as a general disclaimer that as with a Volcano-Hemera. So already an almost optimal setup for flexibles
I never put glue stick on my print beds. Just make sure you have a properly levelled build surface. I usually print TPU on my smooth PET surface and I cannot complain about too weak or too strong bed adhesion. Same applies to my Ender 2 with stock surface and bowden setup. I lowered the print speeds drastically on the ender, btw.
