Parts of the first layer won't stick to the heatbed anymore
 
Notifications
Clear all

Parts of the first layer won't stick to the heatbed anymore  

  RSS
Bacab
(@bacab)
New Member
Parts of the first layer won't stick to the heatbed anymore

Hi,

It's not a first print issue but I wasn't sure where to post this help request. If it's not in the appropriate category I apologise and could a moderator move it to the correct location ?

For the past four years I have operated my Prusa i3 Mk2S without any issue. However this changed recently and I am no longer able to print correctly. I have 2 problems with my prints :

- at the start of every layer the printer draws the outboard lines of the object : this part of the layer does not stick to the heatbed. Since I am mainly printing parts with screw holes, it means the holes are not correctly printed.

- the extremities of my prints tend to warp during the printing, something I had never experienced before. It is so bad the nozzle is striking it so before anything breaks I have to stop the print.

The objects which I'm struggling to print where printed successfully with the same gcode several times in the past few days. I did change the filament but for the exact same type (ColorFabb Silver PLA economy), I just replaced the empty spool by a full one.

Before asking for help I have tried redoing the first layer calibration and found out I needed to set the Z tuning to -0.61 (was -0.57). I am wondering if this could be the indication of a used nozzle. Indeed I have never replaced it (the total amount of PLA printed is ~3 kg, I have never used anything but PLA). Could my issues be solved by replacing it ?

Currently I am printing at 60% speed and with brims to stop the extremities from warping. However this does significantly lengthen the print duration (and only partly solve the problem) so this can only be a temporary solution.

I thank you in advance for any help you can provide.

Posted : 25/04/2021 8:58 am
cwbullet
(@cwbullet)
Member
RE: Parts of the first layer won't stick to the heatbed anymore

Have you check to see if your first layer is correct?  Sometimes you can get a shift to you Z offset.  

--------------------
Chuck H
3D Printer Review Blog

Posted : 25/04/2021 12:35 pm
Diem
 Diem
(@diem)
Illustrious Member
RE: Parts of the first layer won't stick to the heatbed anymore

The two main reasons for previously flawless prints beginning to lose adhesion are bed cleanliness and first layer drift.

Your regular bed cleaning may be leaving micro traces of, er, something or other, which has built up to become an issue.  A really thorough clean with hot, soapy, water followed by a rapid wipe with acetone  might be enough to rejuvenate the print bed - or it may have reached the end of it's life and need replacing.

Your new first layer calibration should be OK.  It's probable that you have worn the face of your nozzle back with use but unless the actual print quality has dropped it should have some life left in it.  Buy a replacement now and hold it as a spare for the inevitably inconvenient moment when it does expire.

And your old filament may have become damp, the new should be OK for a while.  Look up threads on here about drying filament and learn how to make it useable again.

Cheerio,

Posted : 25/04/2021 1:53 pm
Bacab
(@bacab)
New Member
Topic starter answered:
RE: Parts of the first layer won't stick to the heatbed anymore

Thank you for your answer.

@cwbullet : I don't quite understand your answer. As I've said the first layer is not correct since the outboard lines do not stick to the bed. However I have redone this step just after the first failed print : https://help.prusa3d.com/en/article/live-adjust-z_112427 and I have a result similar to the one in the good picture.

@Diem : well it doesn't cost a thing so I'll clean more thoroughly the bed.

The issue is with the new spool filament. The old one was OK. I'll try a different filament if the cleaning of the bed is not enough.

Posted : 25/04/2021 7:46 pm
Diem
 Diem
(@diem)
Illustrious Member
RE: Parts of the first layer won't stick to the heatbed anymore

If you have problems with the built-in first layer calibration routine there are alternatives.  See this page by a regular poster here:
http://projects.ttlexceeded.com/3dprinting_mk3_live_z_calibration.html

and look at this thread:
https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

Cheerio,

Posted : 26/04/2021 10:36 am
Bacab
(@bacab)
New Member
Topic starter answered:
RE: Parts of the first layer won't stick to the heatbed anymore
Posted by: @diem

If you have problems with the built-in first layer calibration routine there are alternatives.  See this page by a regular poster here:
http://projects.ttlexceeded.com/3dprinting_mk3_live_z_calibration.html

and look at this thread:
https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

Cheerio,

The built in first layer calibration works well because it prints relatively long straight lines at low speed. I'm having trouble when the printer prints the shape of the objects (its walls) at a fast pace at the beginning of every layer.

Posted : 26/04/2021 4:57 pm
Diem
 Diem
(@diem)
Illustrious Member
RE: Parts of the first layer won't stick to the heatbed anymore

Go with whatever suits you, use the links for background info.

Cheerio,

Posted : 27/04/2021 12:03 am
jsw
 jsw
(@jsw)
Famed Member
RE: Parts of the first layer won't stick to the heatbed anymore

You can slow the print speed down by any of various means.  I've found that prints sliced with Cura (at least the version I have) print much too fast on the I3 on the first layer and I had to slow that for results equal to PS.

I also use the build-in Z calibration for a quick sanity check.  For a more rigorous one I'll use that 3x3 square pattern.  For the smooth sheet I'll tune for the best 'squish' and for the textured sheet I'll tune for the point just where the 'brush strokes' disappear from the surface that's in contact with the build plate.

Posted : 27/04/2021 12:17 am
Bacab
(@bacab)
New Member
Topic starter answered:
RE: Parts of the first layer won't stick to the heatbed anymore

Ok it's working better now. Thank you again for your answers. In case someone experienced the same issue here is what I did :

- clean the bed with hot water and soap;

- push the Z axis to its upper limit;

- clean the nozzle;

- change from Cura to Prusaslicer.

I successfully printed the part that warped so badly last week 🙂

Posted : 01/05/2021 7:32 pm
Share: