Home JGAurora A5 & A3S Getting Started & Troubleshooting

Bed Adhesion and PLA Curling

cs2000cs2000 Posts: 56🌟 Super Member 🌟
Hi all,

Been trying a few test prints on my A5 yesterday, my first print after a mesh bed level was a benchy, that worked really well to say its a stock machine, very impressed. That was with the included PLA fillament which (surprisingly) seems to be pretty decent quality!

I created come GCODE from a file i had been printing on another 3d printer of mine, loaded in my standard filament that i always buy and hit print, this model has a large-ish flat surface, about 70x50mm base. My standard printing temps for this PLA ive been using for years (the same brand, not the same reel !) was 60 bed and 185 nozzle.

After about 3 layers however a thin section of the base started to curl up, by the time layer 3 had completed and 4 started, it was fully peeling off of the bed so i abandoned the print.

I then did some more reading, plenty of people, including the rep rapper wiki said to print PLA with a nozzle of around 200 and NO heated bed. So, undeterred, i set the nozzle to 200 and set the bed to 35, just to give it some heat and just left it to print as the first couple of layers seemed to go down really well. I came back 60 mins later to find the piece completely detached from the bed and HUGE ball of plastic stuck to the nozzle scraping all over the bed  Cut 15 mind if trying to get molten plastic off of the hotend, to some degree of success :'(

Im using Simplify 3d to slice with the FFF (machine profiles) from DaHai (a respected member around these parts from my understanding) at his Thingiverse post https://www.thingiverse.com/groups/jg-aurora-a5-owners/forums/general/topic:26051

The only basic difference between my old and new printer is that my old one was fully enclosed and it had a PrintBite build surface. I have just ordered a PrintBite sheet for the A5 as i like it as a surface.

So essentially, what are other people printing PLA at temperature wise and not have it peel on the base? Ive never ever seen this with PLA, i thought it was more of an ABS issue. I've heard PLA is liable to curl/peel if the bed is over 65 however?

Bed adhesion is really good, mesh levelling has been repeated multiple times too so i dont think its a levelling/first layer speed issue.

Comments

  • Der_MuckDer_Muck Posts: 265🌟 Super Member 🌟
    So your problem is warping and bad bed adhesion with PLA, right?
    Firstly, it always can be that a spool dont have the right filament on it. Wrong declaration of a spul can happen, keep that in mind but its very very rare.

    Correct cleaning of the black diamond bed is very important. Never use anything other than spiritus.
    Never use adhesion helpers like Uhu Stick, after that the hot bed is broke and will never be useable again.

    Check your layer high, when using a 0,4mm nozzle set it 0,15-0,2 and dont use paper for that!
    Check if the slicer set the first layer high correct. Means that you set the printer to 0,2mm but the slicer beginn to print with 0,2mm equals in a first layer high of 0,4mm. Than you have a problem with bed adhesion, that happens to me.
    In that case you have to set the slicer on Z down to -0,2mm. But be sure that is your problem, otherwise you will end in a scratched bed!
    Simply stop the printer after or wile it prints the first layer. Than get the first layer off and measure it. when its more than 0,2 you have that problem.

    PLA settings are always in the near of 55-60 on the hot bed and 190-200 on the nozzle. Printspeed is about 55-60 to beginn with. 

    Best luck!

    P.S. I print ABS without adhesion problems, PLA normaly has the best bed adhesion next to PETG on the black diamond coating.
  • AuswandererAuswanderer Posts: 8Member

    My A5 has no problem with adhesion with the following settings:

    extruder temp initial layer  :  225 deg

    extruder temp other layer  :  190 deg

    bed temp initial layer         :    55 deg

    bed temp other layer         :    50 deg

    flow inital layer                  :   105 %

    flow other layer                 :     95 %

    print speed                       :     80 mm/s

    print speed outer wall      :     30 mm/s

    layer height                     :     0,2 mm

    print always only with skirt, very small object to.

    bed cleaning only with spiritus, every time !

    works with "EcoMaylene","Colido" and diff PLA's.

    Thanked by 1Samuel Pinches
  • Samuel PinchesSamuel Pinches Posts: 2,997Administrator
    edited March 2019
    I always strongly recommend these tips: http://jgaurorawiki.com/a5/bed-adhesion

    Note: these tips are only specific for the stock black diamond surface.
    Post edited by Samuel Pinches on
  • Der_MuckDer_Muck Posts: 265🌟 Super Member 🌟
    edited March 2019
    Dont go under 55°C the bed temp. should be the same, from the first layer to the last.
    Try 60-65°C it should be better.
    Lower the first layer speed down to 30% 
    80mm/s is pritty much of max. printspeed where you can get prints which are ok. I never printed so fast and my A5 is totaly modded.
    Try 65mm/s to see if it helps.   Try printing the first 2 layers at 200 and the rest with 190-195 should be better.
    High temps degrade the filament in the nozzle like it degrades at to slow prints.

    And be sure the 0,2mm are right. If you have your nozzle to low it also equals in a downscratched first layer.
    0,2mm nozzle hight, 90-95% first layer high at 120-130 print width should be ok.
    Post edited by Der_Muck on
  • cs2000cs2000 Posts: 56🌟 Super Member 🌟
    Thanks guys, seem to have got it mostly resolved by just dropping the bed temp to 55 from 65.

    The parts were well adhered to the bed in the first layer from my testing, i believe the extra heat just caused it to vurl and weaken its adhesion. Either way, i have some Print Bite coming anyway which ive used on my previous printers and makes bed adhesion a thing of the past. With my past machines i got into the "just hit print, make sure the skirt prints OK, if it does, i can walk away" type of trust :)
  • Der_MuckDer_Muck Posts: 265🌟 Super Member 🌟
    Its normal, I also have PLA types that are very different from each other.
    Some just print well at 195 some need 220, its very strange...
    The glass temp. is also different, I was drying 2 typs of PLA, the JG yellow standard one and a Janabex PLA test sample.
    After 3h in the oven at 50-55°C it showed that the JG PLA was dry and the Janabex was ready for the trash :D It got weak and shrunk to a 3mm fillament haha  In such a case the Janabex would need a 50°C bed and the JG filament is fine at 60. 
    Just a case of material mixture.
    Normaly the JGs Diamond Plate is nearly the best you can use. I was printing PLA, PETG, ABS, ASA, TPU and PA Neat with it and everything stick very well to the plate. Only with ABS I was printing with a skirt and never printed with a brim.
    My next mod will be a Carbon easy to change plate with Kapton-tape, ofcause own build. I like the diamond plate very much but on the end of the life time of the diamond plate, I wanna have tested the carbon solution and choose the right next plate. 
  • BigtriverBigtriver Posts: 9Member
    I’m putting this on as many places as I can to help those like me who have been frustrated by bad print adhesion - but geckotek sheets.  They really work wonders for bed adhesion.
  • Samuel PinchesSamuel Pinches Posts: 2,997Administrator
    I'm going to link to this new thread for further discussion on alternate print surfaces: https://jgmakerforum.com/discussion/790/print-surface-discussion-bed-adhesion/
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