Bed Heatup stops

Hi, After   some!  time with PLA  i bought some abs, and felt like trying it; yet i have a strange  problem:

as I read here Put in   110 Bed  / 240 For abs 
the moment i  Tried  ABS for the first time, the whole thing frose on me  ~ 98 degrees ; 

Heating failed, system stopped! Heater_ID: bed

 WHATS  up with this  JGAUrora a5?
I did Update the firmware  and the Interface  firmware before,

and   just now i am trying it with "Just 98 Degrees anms so far it loks like it sticks,.. 

Help! :=)


  • EyeEye Posts: 14Member
    Well i t does not stick  ;(

  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    I've never tried to print ABS, but I seem to remember reading that the firmware limits the bed temperature, probably the hot end temperature as well - if so, the firmware will need to be edited

    Info will be on here somewhere
  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    Also, people who print ABS, would consider running the bed with an external MOSFET and separate power supply
  • EyeEye Posts: 14Member
    hi, do you recallif that is  a  limtation on the  Comuinty  firmware ?

    Sorry i am Not english Native  do you mean some ;  Hardware manipulation  with that mosfet?

  • Samuel PinchesSamuel Pinches Posts: 2,628Administrator
    Hi @Eye, the bed should be able to heat up to 105C without issues. Make sure the room is not too cold. Factory or Community firmware, both should work.
  • Samuel PinchesSamuel Pinches Posts: 2,628Administrator
    But 110C may be too hot for the bed to reach. Power supply is not powerful enough to reach that easily.
  • EyeEye Posts: 14Member
    the whole shebang Does   a hard stop with error  at ~98°  sadly?

    and i did not get ABS to stick so far  For longe then a cupple of min

  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    Easy way to use an external heated bed MOSFET is to take the existing controller board bed output and use it to trigger the external MOSFET - the heated bed is then powered by the external MOSFET which is powered from an external power supply

    Lots of different makers of external MOSFET boards - MKS is probably as good as any:

    Somebody I know of who prints ABS with a JGAurora A5 printer has his printer in a temperature controlled, fume extracted, heated cabinet - ABS produces toxic fumes that should be vented to the outside of the building

    A video:

  • Samuel PinchesSamuel Pinches Posts: 2,628Administrator
    If the heating is stopping at 100C then there is a fault. Is your room very cold? Can you please inspect the plug on the side of the heated bed, and closely examine it. Is there any darkening or burning on the plug?
  • Samuel PinchesSamuel Pinches Posts: 2,628Administrator
    @Stephen Todd  - I'm aware there are benefits to mosfets, but in this case this printer is not meeting the typical performance for one of these printers. So I think we need to identify the cause of the fault first.
  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    JGAurora themselves say maximum temperatures:
    Hot end 240c
    Bed 100c

    He got to 98c, which is close enough for "estimated" temperatures

    Without the printer in a warm cabinet, I think he's pushing the printer to the limit
  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    Maybe a quick fix - glue a cork tile under the heated bed, so the bed heater is more efficient
  • Samuel PinchesSamuel Pinches Posts: 2,628Administrator
    edited May 3
    JGAurora's max temps are the largest they can safely guarantee. Some people are able to achieve 110C, I typically get about ~105 max stable temp. Yes, 98C is close, but still low enough that I personally think it warranty investigation - if it a burning connector it could be a safety issue.
    Post edited by Samuel Pinches on
  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    Yes, I see your point about it being a possible safety issue

    I'd heat the bed alone, without the hot end heated, and see just how high the bed temperature reaches, and if it goes higher, does anything start smouldering - could be the wiring itself getting hot and wasting current
  • EyeEye Posts: 14Member
    The Printer stands in my livingroom,  around 20 degrees;  I build it with a cork flor and;i had It  sourounded with 4 cm high "walls; so the heat could build up a bit but not to much 

    The  heatup stops before reaching its Peak, so the   Heatup of the printe head is not eaven started

    So how come if the 110 is outside Of the  parameters   its the recomedation For ABS

    If  ~97  is   what i can Get"Save" / it is "working as expected,..
    how do i get abs to stick with it ;)

  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    The reported temperature is only an estimation - you would need a calibrated infra-red temperature gun shining on the bed to get a true temperature reading

    The 3D printer measures voltage, not temperature, and estimates the temperature from the voltage it is seeing via a thermistor and resistor voltage divider circuit - not at all accurate really, as the two cent thermistor used is only accurate to plus/minus 5 percent - the other component is a quarter cent resistor accurate to plus/minus 5 percent - so accuracy could be worst case 10 percent variation from printer to printer - this could be why people are getting different temperature limits

    And that is if the power supplies are all precisely adjusted to 24 volts output - otherwise more inaccuracy is added

    Vin is 24 volts
    Rs is a 5 percent accurate resistor
    Rt is a 5 percent accurate thermistor

  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    edited May 3
    So, you could cover the bed with Kapton tape - ABS is said to stick to it

    Or, you could coat the black diamond ceramic coating with an ABS juice - ABS sticks well to ABS - but I'd clip a glass sheet or mirror to the bed and put the ABS juice on that, in case the ABS pulls off the black ceramic coating (part may stick too good)

    Post edited by Stephen Todd on
  • EyeEye Posts: 14Member
    Hi thanks for all the answers, the   laser   Termometer  is Kind of  al over the place (seems the plate is not Verry uniformly heated?

    funny is i have  some  Mirror Tiles leftover here, and  recently For cleaning bought some acetone,  Seems i have to do some chemistry next  time i find some time ;)

  • Samuel PinchesSamuel Pinches Posts: 2,628Administrator
    Please be aware: acetone will damage the black bed coating. I recommend using isopropyl alcohol or ethanol.

    did you inspect the connector on the side of the bed?
  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    Bed heats in the center, and will be hottest there - that's where the thermister is as well - soldered to the underside of the exact middle of the bed, so only place you really want to check is the middle - heat will spread out from there eventually, but will never be the same temperature all over the bed

    Mirror tile is the way to go - I forgot that the black ceramic coating is not acetone proof

    Seems simple enough - put 50 ml of acetone into a screw top glass jar, add 5 grams of ABS filament or scrap ABS print material, leave overnight to dissolve

    Fumes would be my main worry when messing with ABS
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