Hemera gears seizing mid print.

Discussion in 'HotEnds & Extruders' started by Zakm0n, Dec 26, 2019.

  1. Alpha418

    Alpha418 Member

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    Took it apart and found the issue.

    [​IMG]

    Very disappointed. Wasn't even able to get a complete print out of this before it failed.

    The gear is completely cracked and missing teeth. This was only when using Prusament PLA.
     
  2. Impact

    Impact Member

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    Hello again, tough to see so many people having these issues.

    I completed several smaller prints since replacing the stepper-motor. Currently 50% into a 24h Job (on which it failed last time).

    The pinion gear on the new stepper looks good so far. However the (non-replaced) bigger gear is still producing this fine powder which looks like rust. Can't really tell if the spacing of the die-cast part is of, or the gear material is bad.
    Consequently I am a bit concerned about the longevity and would prefer a complete replacement.

    Furthermore, during re-assembly (after inspection) I scuffed up my heat-break in the top section. It seems that the bigger gear is not meant to be removed/installed without unscrewing the heat-break first. Due to the heat-break protruding the machined cut-outs for the gears and bearings for some millimeters.
    Recommendation: It would be nice to mention this in the data sheet or assembly guide.

    In summary the failure left a bit of a bad aftertaste, Hemera performance is great as long as it works, but I would like E3D (and their resellers) to investigate what went wrong and meanwhile offer a replacement for the complete kit, just to be sure.
     
  3. Alpha418

    Alpha418 Member

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    Even worse, it looks like the drive hobb assembly cannot be purchased separately. If this part fails like it did for me then you'll have the buy an entire extruder kit.

    Literally every other part can be purchased seperately, but not the drive hobb.

    [​IMG]
     
    #23 Alpha418, Jan 5, 2020
    Last edited: Jan 5, 2020
  4. yngndrw

    yngndrw Well-Known Member

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    You could "re-pin" the existing cable that you have in order to convert the pin-out between the two motors - Can be a little fiddly but it's often easier than re-routing a new cable or making new longer cables.
     
  5. Maxbots

    Maxbots Member

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    Yeah, after sleeping on it I realized that is the simplest solution, but still a PITA.
     
  6. Daniel Rock

    Daniel Rock Well-Known Member
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    Hello everyone,

    I have had a read through this thread and at this point in time I do not have a quick fix for this. Any cracked gears or brown deposit is fully covered by our warranty and will replace any parts if required. if you can contact support@e3d-online.com with images of the failures you are seeing along with your order numbers we will aim to get you back printing as soon as possible. Apologies for any inconvenience this has been causing.
     
  7. Rafi Shamoon

    Rafi Shamoon New Member

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    The heat brake shouldn't pass inside the gear assembly and you should still be able to remove the gear assembly with out removing the the heat brake.
    edit adding photo :[​IMG] source: "https://toms3d.org/2019/12/10/hemera-review/ "
    batch 2259-13 , mine still working fine purchased directly from e3d UK , greeting from Australia
     
    #27 Rafi Shamoon, Jan 7, 2020
    Last edited: Jan 7, 2020
  8. yngndrw

    yngndrw Well-Known Member

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    Hi Daniel,

    Is this recall for specific batch numbers, or just units which are showing increased wear? How much wear is normal / expected?
     
  9. Daniel Rock

    Daniel Rock Well-Known Member
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    I phrased that badly, not all Hemera units are affected. In the event, you are seeing extreme extrusion issues, after all the necessary calibration/setup steps we will offer a complete Hemera replacement. If your Hemera unit is printing fine... well then your Hemera is printing fine and doesn't have an issue.

    This is not the same as a bearing gate situation. If there is an issue with your Hemera it will be immediately obvious, it isn't a case of it will work for 3 weeks then suddenly break.
     
    Georgia E3D and yngndrw like this.
  10. Impact

    Impact Member

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    Hi Daniel, Thanks for providing some official feedback to the discussions.

    I am not exactly sure that your statement should be understood in this way, but in fact, my printer worked fine (better than ever actually) for nearly 1 week and then broke on an overnight print. Unfortunately I already disposed the failed print, but one could clearly see under extrusion before complete failure for more then a few layers.

    Despite all that, Hemera still is easily one of the best 3D printer add-ons I ever bought and would still highly recommend getting it.

    BTW: is support@e3d-online.com taking care of any order (including resellers) or just the ones from E3D directly?

    Greetings from Germany.
     
  11. Daniel Rock

    Daniel Rock Well-Known Member
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    Yes, Support will be accepting requests from users who purchased from resellers for the hemera gear issues, make sure you send a screenshot or copy of the order confirmation from your reseller.

    So it’s up to you weather you want to come directly to us or speak to your reseller first. All resellers should be aware of the current situation.
     
  12. ali3d

    ali3d Member

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    Ordered a 24V Hemera from FilamentOne and received it today. Unit is completely seized - cannot even rotate by hand. I found this upon inspection before attempting an install and plan to return it. Seems e3d is lacking or failing at quality control. Batch: 2257-6

    Is there a way to order a unit that does not have this issue? Is the best approach to do an exchange through e3d? Why are dealers still shipping defective units? I feel like I want to give it another chance but don’t want to waste time and money shipping products back.
     

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  13. Daniel Rock

    Daniel Rock Well-Known Member
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    If you contact support@e3d-online.com with a copy of your order confirmation from FilamentOne, we will send you out a new unit. I can assure you as soon as the cracked gear issue was identified we paused shipping for a 100% QC on all the gears, and contacted the resellers with instructions on how to do the same.

    As the current stock of Hemera's have been 100% QC'd we are confident further cracked gears won't be shipping out from now on.

    Apologies for any inconvenience caused, we are aiming to release a blog post in the near future explaining in detail the reasons why the gear was cracking and how we have combatted the issue.
     
  14. ali3d

    ali3d Member

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    I e-mailed Hemera with all the information on Friday and never got a response - ticket #38897 :(
     
  15. Thorinair

    Thorinair Well-Known Member

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    From my experience, it takes them 2-3 work days to reply, so hopefully they will reply to you today :)
    I feel lucky that my Hemera doesn't have any of these issues... I really do wonder what is the real cause behind this.
     
  16. Daniel Rock

    Daniel Rock Well-Known Member
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    Sorry to hear you haven't got a response yet, support is experiencing a bit of a backlog at the moment, I will pass the ticket number on and see if I can get you pushed up the queue a bit.
     
  17. tonyowens_uk

    tonyowens_uk Member

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    Hemera seems to be designed as a cost efficient compact direct extruder for near ambient temperature enclosures with some emphasis on filament constraint. But I wonder whether there is a reliability issue with using unprotected fine module reduction gearing in a dirty environment? Accurate control of the centre distance of motor pinion to large driven gear is managed - how? And how much does the heat treatment of the stainless gears and hobs affect their dimensions?
    I would guess that some of these issues relate to the working out of manufacturing process controls (incomplete development). But the decision to use open gearing in this environment is - interesting. Compliments to the engineering team on an interesting product that I believe just needs a bit more discussion, testing and maturing. I was considering doing a water-cooled adaptation, but that looks premature...
     
  18. Thorinair

    Thorinair Well-Known Member

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    Yeah, I agree with this. I love my Hemera, but the open gear system has some problems - I had a wire holder from my printer fall directly INTO the Hemera, as it is all so open. Also, if there is any sort of grinding of the filament by the hob, the shavings drop onto the hotend block below, forming a melted pile over time.
     
  19. Guilouz

    Guilouz Member

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    @Daniel Rock

    How many times it take to get a response from support ? I have a similar issue with brown deposit and send email 3 days ago. Ticket number 39065.
     
  20. Daniel Rock

    Daniel Rock Well-Known Member
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    We are answering emails as quickly as possible, I don't have a timeline as to how long it will take as every email requires a different length of time to answer. I will pass on your ticket number and ask if yours can get looked at, but it's very much a case of first come first serve with emails.
     

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