Why doesn't PLA stick to heated bed?

10

I have a basic Creality Ender-3 with a black rough bed cover. I'm printing with PLA.

After assembly, I printed 3 or 4 small toys sliced by Cura with basic settings. All were printed very well!

However, after that, extruded filament would not stick to the bed. I tried the following:

  • Bed calibration with A4 paper (each corner with a tight nozzle to paper and repeated calibration again)
  • Once raised up the bed temperature from stock 50 to 60 °C
  • Washed the bed with a soap and water (and dried)
  • Sprayed with a hair spray
  • Changed the filament

Nothing helped so far.

What else can I try?

Roman Matveev

Posted 2019-11-03T15:41:37.627

Reputation: 203

3

Not all hairspray brands work! Have you tried glue stick, wood glue, etc.? Have you tried larger first layer height? Slight over-extrusion on first layer, higher first layer temperature, etc.?

– 0scar – 2019-11-04T10:36:38.397

Answers

11

I think you may have used the wrong substance to clean your bed. Try using Isopropyl Alcohol (IPA). You may have left some residue behind from the soap, which is now interfering with adhesion. When that is done, ensure you've gone through the steps for bed leveling again. It's amazing how much of a difference proper bed leveling makes in adhesion. If it still doesn't work, post some pictures up of your results, which will help tremendously in getting you a better answer.

Pᴀᴜʟsᴛᴇʀ2

Posted 2019-11-03T15:41:37.627

Reputation: 2 271

As an addition to Pᴀᴜʟsᴛᴇʀ2's answer, I found that when using hairspray, some brands of hair spray add some sort of ingredient that gives it a sort of a glossy finish which makes the print not stick to the bed. The stuff I use is 3DBilby's 3DLack which can be found here. It costs quite a bit but gives very good results. When cleaning the bed, especially when using ABS, a stronger solvent like Acetone works as well.

– HotGlue – 2021-02-21T04:22:57.193

2

Soap and water are absolutely the wrong stuff for cleaning the print bed. It's a base, and bases are slippery. This helps things like dirt slip off when we clean, but will also make it harder for filament to adhere to the bed. Instead, use rubbing alcohol, which is slightly acidic.

Additionally, not all hairsprays are good for this. There is a certain ingredient you need, and some don't have it. Others do have it, but also have other things that interfere. AquaNet is known to be good for this. You can also buy made-for-purpose spray for 3d printing beds.

Joel Coehoorn

Posted 2019-11-03T15:41:37.627

Reputation: 1 742

1

Set the bed temperature to the glass transition temperature, around 80 °C for PLA:

  • Filament is slippery and non-adhesive at room temperature

  • Filament becomes sticky when near its melting temperature

  • Printed items can pop off of the bed by themselves when cool. This shows that they become less sticky when cool

I was told about this and have been successfully printing PLA without rafts, brims, skirts, etc.

Try a tiny print such as a small temperature tower to start.

Note: I've only been using PETG recently and continue using 80 °C; perhaps a bit of 'elephant foot' occurs. However I'm primarily doing structural prints (tools, cord hangers, etc.) and strength and print reliability (tall prints not coming loose during printing) are my highest priorities.

I appreciate the suggestion of dropping to 75 °C for later layers and will try that.

Technophile

Posted 2019-11-03T15:41:37.627

Reputation: 113

2

The glass temperature of PLA is about 60-65 °C, too high is not beneficial for printing. A temperature of 80 °C is more used as a bed temperature for PETG.

– 0scar – 2019-11-05T22:09:49.237

@Oscar How not beneficial for printing? I have been getting what appear to be excellent results. – Technophile – 2019-11-08T16:30:01.550

1

A too high bed temperature can cause elephant foot.

– 0scar – 2019-11-08T21:26:18.513

Thanks, I'll watch for that. – Technophile – 2019-11-30T19:39:15.123

1I have an Ender 3v2 with a glass bed. I like to use 80 °C for the first layer, and 75 °C for the other layers. If I set the bed temperature any lower, I have to add a wide brim to just about anything I print. – mrog – 2021-02-20T16:07:12.343

Re suggested temperature format edits, please see https://sites.google.com/a/ngs.org/ngs-style-manual/home/T/temperatures

– Technophile – 2021-02-22T15:22:21.927

@Technophile I did see the site you suggested. 3DSE has its formats as well. Please see Useful things to check for when cleaning up posts.

– agarza – 2021-02-22T19:15:14.540

@agarza following its link https://3dprinting.meta.stackexchange.com/questions/297/dont-forget-the-space, I do see that an nbsp is required.

– Technophile – 2021-02-22T21:33:04.243