Tpu jams just like everyone else is reporting above the extruder gears shortly after starting a print. Firmware has been updated, vref set at .5, and esteps calibrated. Have tried running with retraction between 0 and 2mm. Have ran with multiple idler tension settings starting at e3d recomended and down to no tension at all. This thing ran brilliant for a couple hours then it can hardly lay down the first layer without jamming. I bought this solely for the pla like print speed of flexibles like the video proclaims and it fails miserably. So e3d how are you going to make this right? More importantly when, I see unansweree threads on this going back weeks.
There seems to be a problem thats widely observed and that is not being addressed. To collate the things I have tried and changed to date. can print other filaments fine and dandy, so for the most part setup is verified. Upgraded printer firmware. Calibrated esteps and extrusion to within a fraction of a MM Have now tuned the vref (only done this out of desperation as it was working fine, no skipping or overheating) Ran with printers stock fan (this is going from memory, forgive me any innacuracies) which shifted around 7 CFU, Hemera supplied fan which I think shifts 8.5 CFU and 40x40x20 upgraded fan which shifts approx 10.5 CFU. Used cleaning filament to ensure no residual inclusions in hotend. Ran every TPU I have tried across a range of temperatures. Ran every TPU I have tried at at 0 to 1.5 retraction. Ran every TPU I have tried with every part cooling fan speed from 0 to 100% including kicking in at assorted layer heights. Ran every TPU I have tried at assorted print speeds from 20mm/s to 60mm/s. Edited my profiles endlessly ( I have several printers with working TPU profiles so not a novice). Sliced with Simplify3D, Prusa Slic3r, Cura. Some pretty extensive testing and many hours/days lost. With every TPU it's the same, starts off well and goes to hell at some point. Sometimes after a few layers, frustratingly sometimes after 1-2 hrs. Oiling works and has allowed me to complete several TPU prints. I'm not happy with this as a solution. I'm chasing my tail and I'm all out of ideas. I've been 3D printing for longer than most I suspect and this is a battle I'm not winning.
I couldnt agree with you more Danny. My printer runs pretty much 24/7 with tpu parts for rc vehicles. 95% of the time I'm running tpu. I have tried multiple hour prints with pla and have had no problems. I suspect petg will be the same. I'm disappointed at the lack of acknowledgement by e3d and no news on root cause analysis or if they're doing anything at all about it. It's not like we're trying to make it do something it wasnt designed for. We are trying to use it exactly as they advertised and it doesnt work. E3d needs to either come up with a solution or stop misrepresenting hemera capabilities. I've chatted with e3d support people and they're clueless to this issue. So frustrating...
I gave up my Flexion for better PLA and PETG retract performance but, TPU was a no brainer. I am leary of going down the road of problems I read about in this forum with the Hemera I purchased. So far I spent enough time designing a custom carriage mount for the Hemera on the Wanhao i3.
I'm clutching at straws now but is it right that the Hemera has this nasty jagged hole with something sticking out? I've seen loads of online images but none seem to show it at an angle I can relate to. I knowone thing for sure if I can't get it to work it'll have a bigger hole in it before long.
Hi Danny, I can see you are using a Noctua fan, please put the fan back to standard, we aren't able to provide support to modified Hemera's
I would but health and safety guildelines forbid me working in the same environment as the stock fan without industrial hearing protection. The super noisy stock fan was also an issue raised on here which wasn't addressed BTW.
You may want to double-check that you have the correct voltage fan for the power supply you are using. The stock fan certainly shouldn't be loud enough to require hearing protection. Has one of the fins bent/ melted?
The Noctua fans don't supply enough air, as it was previously stated by Sanjay himself: https://www.reddit.com/r/3Dprinting..._their_new_extruder_hemera/f9k4cms/?context=3 I personally use Sunon's 6000 RPM 4020 fan, as it supplies more than enough air, but is quieter than the stock: https://www.tme.eu/hr/en/details/mf40201v2-a99-a/dc12v-fans/sunon/mf40201v2-1000u-a99/ I do agree that the stock fan is ridiculously too loud, but Noctua won't do it. If you have tried to disassemble the Hemera, you would notice that the "something sticking out" is literally just the peg which holds the idler lever, so there is nothing wrong with that. I have been printing TPU without any issues at all. I wouldn't say that everyone else is reporting it not working, but rather just a vocal minority. The Hemera works perfectly fine for most people... Maybe there is an issue with your unit?
Thats why I chose the bigger Noctua (as you have with the Sunon) which actually pushes more air than stock. I'm using the 40x20 according to the data sheet all is good, higher than stock. The vocal minority are actually quite a few in number. I'd say it's the biggest issue in this particular forum if you read through. Certainly more than an isolated incident. Sorry for late reply Daniel, yes voltage is correct (24v) and no there was no damage. The stock fan will never be put back as I print in the room next to where I sleep.
If you would look at the specifications, you would realize that the strongest 4020 Noctua fan (https://noctua.at/en/products/fan/nf-a4x20-flx/specification) is extremely weak. It pushes 9.4 m3/h with 2.26 mmH2O static pressure. In comparison, the Sunon fan I linked pushes 13.01 m3/h with 4.21 mmH2O static pressure. While there is still no official data, I have managed to dig up this data sheet for the stock fans: https://szdcfan.en.made-in-china.co...ars-Warranty-Ball-Bearing-DC-Cooling-Fan.html My tests have shown that the stock Hemera fans are possibly mislabeled. They are labeled as XYJ12B4010M, but a Sunon fan of equivalent specs is much much weaker (I have bought an "M" equivalent Sunon at first, and then realized it blows like, 2x less air when holding a hand against it). This makes me believe that the stock fans are actually XYJ12B4010H. Direct dBA noise level comparisons would point to this as well. There is no way that the slower "M" fans would be this loud. If all of this is valid, then the stock fan pushes 11.92 m3/h at 4.51 mmH2O static pressure (still even higher pressure than my Sunon!) The static pressure means a lot here. The lower it is, the more it means any sort of obstruction (Hemera's heatsink) will reduce the airflow. Let us look at the stats once again: Noctua: 9.41 m3/h, 2.26 mmH2O Sunon: 13.01 m3/h, 4.21 mmH2O Stock: 11.92 m3/h, 4.51 mmH2O I hope that you see where the issue lies, and why Noctua is inadequate. So no, none of our fans are better than stock. We can get very close, but it is impossible to get that good of an air flow without lots of noise. Noctua however is absolutely inadequate in every regard. You will probably get like half the airflow with it than with stock. I would also like to point out that while it is the "biggest issue in this forum", there is only maybe like 10 threads of so. Consider how many people are using the Hemera now. Don't you think there would be thousands of threads if it was a common issue? That is the definition of vocal minority. Those who are happy and have no issues simply don't post anything, and I am certain there is thousands of them.
I have the "H" model right in front of me (ironically stock oem on my printer before the hemera) and the model supplied with Hemera is not the same. Both in terms of noise and fan chasis. I do get your point however that although Airflow is better @ 9.4 v's 5.32 the Static pressure is indeed 2.26 V's 2.94. I will have to do some testing and put a thermocouple on the h/s to see how each actually affects the cooling. Sufficed to say it's for educational purposes only. I will not be putting the Stock fan back on but would be tempted to have a go with one of the Sunons you are using. I'm on 24v but using a converter for the Noctuas so it wouldn't be an issue either way. Without being pedantic if the number of people posting about the issue on this forum scale up to open support tickets I'd expect there to be a few more than 10. I'm by no means a novice printer, in fact I got into the game quite early so have been around the block. Whilst the issue may not be widespread, it's certainly not isolated.
I agree with Danny, it's very difficult to assess issues people are having based on forum discussions, we often find that people jump on the bandwagon with unrelated issues and assume that their issue is automatically a product fault. When users open a support ticket with e3d-online.com we are able to run through initial troubleshooting steps that rule out assembly/ setup error. If it is a case fo the cracked or misaligned gears we are replacing the cold side (with the 100% QC passed tolerance matched gear pairs) logging as much information as possible to assess the situation on an ongoing basis. One thing that you do have to bear in mind is that a high volume of forum postings are about issues, people who have Hemeras running in print farms running 24/7 without issues have no need to post on forums. So you do have to appreciate that issues will always appear to be more widespread than they actually are if you are looking at a biased sample group. I'm not able to share failure rates publicly but they are very small, in cases where the failures occur we are working hard to get the user back up and running as quickly as possible. I would urge anyone who is getting frustrated with their unit not to try to self diagnose the issue and to just go straight to support@e3d-online.com, where we have systems in place to troubleshoot issues one on one, keeping variables to a minimum in order to get the user printing successfully as quickly as possible. On the topic of variables, using aftermarket parts with Hemera make it increasingly difficult to troubleshoot. If you are wanting to switch out to aftermarket parts (not something we recommend or support) you should always start with a stock unit, make sure you have set it up correctly, calibrate at conservative print speeds, and work your way up from there. This way you are able to figure out what the root cause of the issue you are having is much more effectively.
You mention "oiling" not clear what you mean by that? do you mean actual lubrication. I am having the exact same problem TPU seems like it prints fine then "x" (x being how many birds have flown past divided by tea in china, what I am saying i guess is that its random) layers in it just stops extruding; very frustrating as its my main reason for buying the Hemera. Normal PLA prints like a dream
