Live Z change every time :-(((  

Re: Live Z change every time :-(((

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By browsing the forums I understand that the different temperatures of the extruder would have an influence on the value of Live Z during the initial test before print ?
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no, that's not correct.
different temperatures of the p.i.n.d.a. probe deliver different results for the meshbed levelling.... and so different required values for the live z adjustment.
so if you "park" your extruder way above the heatbed before starting a print, you should get the same (or at least very similar) required live z adjustment levels.

have a look at this thread and read as much as you can (at least the first 5 - 6 sites).

Re: Live Z change every time :-(((

What Jeff has posted is correct, IF YOUR MACHINE IS STATIC. Following his instructions are important.

Variations of that much smells to me like you have something loose, and your machine is not static.
1) Check to see if the screws holding the bed in place are stable and don't have play.
2) Make sure the rods that allow the bed to slide along Y are stable, and there is no play in them.
3) Make sure the linear bearing on the bed are attached to the bed, and that they can't jiggle up and down.
4) Make sure the PINDA sensor is firmly attached, and can't jiggle up and down.
5) Make sure the extruder itself is firmly attached, and can't jiggle up and down.

Many people have a known adjustment for Live Z for different filament types. E.g. ABS requires XX more or less than PLA, etc. But once those are known, there should be no major offsets. These offsets are in part temperature (expansion/flexing) and in part the viscosity of the filament and how well it flows/squashes.

Re: Live Z change every time :-(((

... These offsets are in part temperature (expansion/flexing) and in part the viscosity of the filament and how well it flows/squashes.

ok, I agree at this point. but this won't lead to live z adjustment values with a huge difference of more than a millimeter.
@aaron.s5 what's your experience about the common difference range ?

Re: Live Z change every time :-(((

... These offsets are in part temperature (expansion/flexing) and in part the viscosity of the filament and how well it flows/squashes.

ok, I agree at this point. but this won't lead to live z adjustment values with a huge difference of more than a millimeter.
@aaron.s5 what's your experience about the common difference range ?

I don't use a wide variety of filaments, but would expect it to change by less than 0.050mm. The huge variably discussed in this thread is either a mechanical play, or a highly un-reliable PINDA sensor, or a miss-understanding of what is a good Live Z.

Hopefully between your post, and mine, jean-luc.f can isolate the problem.

Re: Live Z change every time :-(((

Wait with friends !

My printer is new, it does not change place, it was delivered built.
The pinda il fixed.
The bed il fixed, etc.

And I promise you that on a change of filament, I have LiveZ differences of 0.5 mm.

To settings my printer, Jess my advice to read à tread of 24 pages !
I do not have time to read 24 pages and understand english langage, (sorry i m froggy man 🙂 never is perfect !)

So, either, there's no problem, and I do my live Z once and for all.
Either there is a problem if I have to make adjustments all the time for every filament ?

Thank you for your help.

Re: Live Z change every time :-(((

did you enable (maybe by accident) the Temp. calibration -> Temp. cal. [ON] ?
if so: turn it off.
it's a doubtful feature within the actual firmware. and it is supposed that it can not deliver proper results, unless there was a third temperature sensor at the p.i.n.d.a..

about your patience and your "froggy state", nobody is perfect... but in case of 3D printing you need patience and the willingness to aquire new knowledge.

Re: Live Z change every time :-(((

Jean-luc.f,

How do you know your Live Z is changing by this much. Please explain your method.

Things can come loose during shipment. They might have been tight at the factory, but by the time it giggled it's way to you, something might have come loose. Particularly the screws on the bottom of the bed that attach them to the carriage.

Here is a step by step guide to setting up the printer. It is not 24 pages.

http://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/-before-you-ask-troubleshooting-video-updated--t472.html#p39190

On step 6, you can jump to this post:
http://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/life-adjust-z-my-way-t2981-s30.html#p26760
to download the file. You don't need to read the posts up to then, just look at the pictures and you will get a good idea with no language barrier.

The above method will be your fastest way to reduce frustration.

Re: Live Z change every time :-(((

Many tank JeffJordan for your help, ok but the Temp Cal is Off, I would be glad to find this option active !

I just did the Live Z procedure once again.
The differences are incredible.

Before re-doing the full LiveZ procedure, I had a Live Z value at -1,700 to block the white page 😯 .
And Now, my New Live Z is -0.4, 😀
This afternoon, when I print a flexible filament, my live Z was around -0.650 😐
But, to print my flexible filament, I spend a huge time in temperature and liveZ adjustment. 😥 😥
that's crazy.

All this because I change filament is trying to print a 3d piece . ???

Now, I my opinion know that as long as I generate a GCODE at the same temperature for this filament, my Live Z will be pretty correct.

Please, find a genius idea for me.

Re: Live Z change every time :-(((

Please describe your "Live Z procedure" that is giving you these results.

Please check for something loose on the printer. You should not see values moving that much.

Re: Live Z change every time :-(((

Ok so, y adjust my live Z was around -0.4 extruder 26° (11h30 Paris time).

The first test calibration_surface_PLA_75x75@200um_v4.gcode with PLA did not work whith my Previous setting (-0.4).

Now, my Live Z is (+/-) -0.785 with Extruder at 220°
The circle outside of the piece makes it well 0.2 mm, but my piece is 0.3 🙂 my filament is 1.9mm.

1h15 Paris time. 😉

Soon :-)))
JL

Re: Live Z change every time :-(((

Ok, Last night, I left the printer, while I had an impression almost satisfactory.
This morning, I RESTART the same printing of the model 0.2 mm 75X75.
SAME setting, the printer and the same place.

After the first 15% of print, the printer mayby crash ! It's rare, but it happens..
It should be noted that the 15% was very good!

After the crash, I raise the impression, and Bingo, the Live Z is bad.
My seeting in memory is -0.785.
But the result in the bed, means very clearly that the real LiveZ is at 0. 😐 😐 😐

In my opinion, therefore, it is not a problem of geometry.

Re: Live Z change every time :-(((

This evening, returning from work, without touching any settings, I launch the same impression of file 75x75 0.2mm
And boom ! The nozzle once again my bed.
For curiosity, I test a blank page on the nozzle and for move the page, the value of Live Z must be 0 ! 😡 😐

This problem is crazy !
My bed gets worse days after days, I'm not happy !!!

I have to send an email this morning to the service support, no answer for the moment.

Can I hope for an answer in the week?

"Au revoir".
JL

Re: Live Z change every time :-(((

You should contact them through the live chat on the shop webpage.