First layer test, good height, but empty fill towards the right
 
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henkes apps
(@henkes-apps)
Active Member
First layer test, good height, but empty fill towards the right

So I've calibrated my Z values to -1400 and everything prints well. I've tried several first layer calibrations and the sweetspot seems to be around -1400. But I wanted to find the exact best spot. So I ran this test in increments from -1380 (first section at the bottom), in increments of -5  down to -1420.

But when I put the print layer towards a light, mostly on the right side, it shines thru. And previously it printed perfect att -1400. What can be a typical cause?

I printed a mini of Deadpool at -1400 and it worked great. These calibrations where made at about 30 minutes apart. Previously anything from -1380 to -1420 made a first good compact layer, without holes.

Could the plate be warped so it's not -1400 across the plate?

Thanks

 

This topic was modified 2 months ago by henkes apps
Posted : 30/11/2022 1:55 pm
JoanTabb
(@joantabb)
Moderator
RE: First layer test, good height, but empty fill towards the right

Are you using 7x7 mesh bed levelling?  (LCD Menu Option)   

are you using a supa pinda or a normal pinda?

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 30/11/2022 3:12 pm
henkes apps
(@henkes-apps)
Active Member
Topic starter answered:
RE:

Oh, I forgot to mention my setup. My setup is a default MK3s+ without mods, and I'm printing using Prusament PLA basic.

When I tried to print the exact same test now, but fixed at -1400 it printed fine without holes. It almost seems that if you do live Z adjustments, it gets finnicky.

I do 3x3. I will try with 7x7

 

Regards

This post was modified 2 months ago by henkes apps
Posted : 30/11/2022 5:07 pm
JoanTabb
(@joantabb)
Moderator
RE: First layer test, good height, but empty fill towards the right

Hi Henkes, 

the Mk2 had a three wire pinda with no thermal calibration, and Many people found themselves 'Chasing Live Z'

say you build the printer by the book, and run a satisfactory Live Z (You will have started the print very close to the build plate, because that's where the initial Live Z leaves the extruder.... 
then you do a test print, say the Tree frog, Mesh bed levelling starts close to the build plate, because that's where the last print started.... 
mesh bed levelling succeeds and the frog prints nicely. 
so you go for another print, lets say the  Prusa Logo... 
Mesh bed levelling completes ok, the model starts printing,  and the first layer is rubbish. so you quickly re adjust Live Z and all is well, 

Flushed with success you decide to print something else, but you find yourself having to adjust live Z again, this could be, because every time you do a mesh bed level, your pinda ends up a different distance from the build plate, and in a different reltative position to the build plate, I believe these different start points cause different levels of parasitic heating in the Pinda, which cause the pinda to have different sensitivities, and hence live Z suffers
the mk3 and early mk3S printers, had 4 wire Pinda's which were supposed to be thermally compensated... (integrated thermstor in Pinda
this seemed to work for most people, but some still had difficulties. 
some people monitored the Pinda thermistor and initiated the mesh bed levelling when the Pinda achieved a 'preferred' temperature. 

others, like me, just carried on moving the pinda to a given position before each print... both approaches seemed to work.

NOW the Mk3S+ has a 'Supa Pinda'  Once again it is three wire non compensated, but it's supposed to have a better temperature than the earlier Pinda, 
And it seems that some of these Supa  Pinda's start drifting in the face of temperature sensitivity,

you could try always starting jobs with the Extruder at 60mm and central to the build plate, for every print, then hopefully your first layers will be more consistent...

regards Joan

 

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 30/11/2022 8:20 pm
henkes apps
(@henkes-apps)
Active Member
Topic starter answered:
RE: First layer test, good height, but empty fill towards the right

Thanks for the answer. I like to learn about the technincalities 🙂

Ill try that and also a few different settings.
What does "you could try always starting jobs with the Extruder at 60mm " mean?

Also, would it be beneficial to reassemble the S Pinda to a lower point from the beginning and recalibrate. So let's say i mount it lower and do a calibration of -400 instead of -1400?  Would that increase or decrease sensitivity and print results?

Regards

 

 

Posted : 01/12/2022 10:19 am
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