First layer calibation /z level anomilie
Hi there i have had my mk3 kit for a couple of months now, its my fist printer and its working great. My problym is that if i do the fist layer calibration i get a nice smooth adhesion on 0.30 but when i print on that setting things fall apart i then have to live adjust z to 0.40 to get a great print. The only other thing i have issues with is stringing with i fixed be adjusting retaction, any ideas. thanks Uys
Re: First layer calibation /z level anomilie
have you made sure the buildplate is scrupulously clean? any grease can seriously reduce adhesion
-.400mm is not bad for live Z
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
Re: First layer calibation /z level anomilie
Hi Joan , the plate is clean i dont have a problem with athesion its when i run the first layer calibration and get it perfect and then want to print the filament does not get layed close anough to each other to make a joined cerface ,when i adjust z down to 0.4 all is good ,if i take my first layer calibration to 0.4 the block looks plouged
Re: First layer calibation /z level anomilie
Why do you say -.400 "is not bad"?
Should I be aiming for a z of -.400? (Of course not)
Is my z of -1.145 "not bad"?
Is there a range of "not bad" z? What is it?
Re: First layer calibation /z level anomilie
Prusa have adjusted the acceptable range for live z several times. when I started building my kit at the end of September the instructions said to re adjust the Pinda if live z went under -0.999... then the they changed the advice to not under -2.00 and someone said the current word is under -2.50... I keep it between -1.4 and -1.9 sort of out of habit
but if any one wants to chime in with the current actual WORD from PRUSA for the current limits I will adjust to them
Re: First layer calibation /z level anomilie
I want to know why I have to readjust the live z after the first layer calibration was perfect
Re: First layer calibation /z level anomilie
The OP Uys,
wants their perfect first layer to be 0.30mm, and seems upset that they have to change to 0.4 mm before they get good prints otherwise the prints fall apart...
the pinda probe is the sensor upon which these measurements / settings are based.
the Pinda has a finite sensing distance. which is used during mesh bed levelling
once Mesh bed levelling is complete, the pinda is just an obstruction.
in an ideal world the pinda would be well out of the way during printing.
other bed level sensors have a retract facility. Pinda doesn't which is probably a benefit for repeat accuracy,
once the pinda has sensed the distance to the build plate core, we invoke live Z to position the nozzle correctly for our first layer.
the smaller the live Z measurement, the larger the resultant gap between the pinda probe and any model on the build plate
you do want some adjustment, in reserve so that you have the ability to re adjust live z for different filaments or nozzle replacement... and so that you have some additional nozzle clearance when doing the mesh bed levelling.
Prusa used to suggest 0.7mm as being the preferred region for live Z adjustment
however Prusa have increased the acceptable live Z quite considerably in recent times... a large live Z value, puts the Pinda closer to the models when printing, and if there is any warping in the print, then the Pinda is more likely to catch and cause a collision error
every printer is different and has a different live Z requirement.
I would suggest that if 0.30mm live Z produces a perfect first llayer, but you can't print anything on top of it, then the first layer is not perfect.
If 0.40mm live Z produces a surface that the models can build on, then that is a better setting,
If however, the 0.40mm first layer prints then have a rough finish when prints get higher, then there may be an issue elsewhere. (perhaps over extrusion)
if the first layer filaments are not bonding together, which is what UYS seems to be saying is happenning on their perfect layer at liveZ 0.30mm on their printer then our perceptions of a perfect layer differ.
in My opinion, Any live Z that gives an unblemished ripple free first layer, with all of the appropriate filaments bonded together without allowing the pinda probe to snag on the print material, is a good first layer.
Bob, you ask if you should be aiming for 0.400mm, the answer is NO... you should be aiming for a first layer that bonds well to the build plate surface, (without over bonding, ) where the adjacent filament traces bond together to form a continuous sheet, without the nozzle digging into the printed filament or causing it to ripple, and that still leaves clearance between the pinda probe and the models on the build plate.
After that it's down to how comfortable you are with the pinda clearance...
Personally I like to have a smaller live Z and a correspondingly larger pinda clearance,
My mk3 is currently showing -0.745mm live Z with a stickered build plate
my mk2 is currently showing -1.485mm live Z, with a powder coated build plate. if I put a stickered build plate on the mk2, the liveZ would be too close so I would have to adjust the live V to a smaller value also the nozzle is older on the mk2, so when I change it, the live Z value will also need to be made smaller again
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
Re: First layer calibation /z level anomilie
another one of your Stellar explanations Joan thanks from this kibitzer 😉