Notifications
Clear all

Why is first layer calibration limited to PLA only?  

  RSS
ami.l
(@ami-l)
Eminent Member
Why is first layer calibration limited to PLA only?

Greetings and happy holidays everyone!

When using the printer menu to calibrate the first layer, the printer asks if PLA filament is installed.
It then goes on to use the heat settings for PLA.
Why can't we calibrate the first layer for other common materials, such as PET and ABS?

Thanks in advance,

Ami

Posted : 27/12/2018 7:58 am
bobstro
(@bobstro)
Illustrious Member
Re: Why is first layer calibration limited to PLA only?

The firmware routine has to fit into available space, and theyre already reportedly up against limits. It's not that it has to be PLA, but there's very little space for any routine and the printer ships with PLA to test.

The on-board routine is also for a 0.40mm nozzle. You can create your own prints for doing live-Z calibration with any filament or nozzle size you prefer, although using the on-board routine is recommended at least once.

The "https://shop.prusa3d.com/forum/assembly-and-first-prints-troubleshooting-f62/life-adjust-z-my-way-t2981.html&ved=2ahUKEwjr6ZWn_b_fAhVPT98KHTcnCiYQFjAAegQIBxAB&usg=AOvVaw0RHrGj9tuUI3tAbPMDR-I 6">Life Adjust" method is recommended as it is much easier to use and understand. I like to create the print using the filaments and nozzle sizes I use most often.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 27/12/2018 1:13 pm
ami.l
(@ami-l)
Eminent Member
Topic starter answered:
Re: Why is first layer calibration limited to PLA only?

Hi @bobstro and thanks for your prompt reply.

As a software and hardware engineer, I find it less plausible that the few bytes required to add 2 more menu items with different temp settings should be a limiting factor with current memory availability.
If they are indeed struggling for a few bytes of available space, it's time to switch to a larger memory chip, added cost should be negligible.

It does make sense that they have different priorities, but for me, as a new user, needing to replace an existing filament just to do the calibration and back seems redundant, and it would be nice to have this option in the future.
I did the original calibration with the PLA, but I just encountered a printer error (see https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f64/enforced-z-leveling-damaged-pei-sheet-t26779.html ) when using PTE, and wanted to repeat the first layer process, so naturally I went to the printer menu, and was disappointed to see that I will need to switch filaments just for that.

If someone at Prusa is reading this, please add to the future feature list 🙂

Thanks for the link, I will definitely check it out.

Happy holidays,

Ami

Posted : 27/12/2018 6:02 pm
richard.l
(@richard-l)
Member Moderator
Re: Why is first layer calibration limited to PLA only?

I wouldn't complain too much. Before they added this to the firmware you had to do it from a print on the SD card. When they added the mesh leveling, first layer calibration, power panic, collision detection. etc. they were forced to move the language files out of the firmware to another location.

Since they don't produce the boards, Ultimachine does this, they are limited to what is produced.

Posted : 27/12/2018 6:27 pm
bobstro
(@bobstro)
Illustrious Member
Re: Why is first layer calibration limited to PLA only?


[...] As a software and hardware engineer, I find it less plausible that the few bytes required to add 2 more menu items with different temp settings should be a limiting factor with current memory availability.
I'm a computer guy too (networks & security) and was surprised, but my understanding is that the current generation of printers is still running on 8 bit hardware and they're pressing hard against some limits already. If you look at the github comments, you'll see a lot of comments along the lines of "32 bytes recovered".

If they are indeed struggling for a few bytes of available space, it's time to switch to a larger memory chip, added cost should be negligible.If Prusa were doing everything in-house, that might be straightforward, but they're dependent on other manufacturers, and the Marlin firmware itself. Given Prusa's history of supporting older models, it won't be as simple as porting code to another platform.

It does make sense that they have different priorities, but for me, as a new user, needing to replace an existing filament just to do the calibration and back seems redundant, and it would be nice to have this option in the future.I do wonder if they could use the SD card as storage in the future, allowing the on-board firmware routines to load code from there in the menu interface. In the meantime, it's fairly trivial to generate calibration prints ahead of time if you're a coder. I've got batch routines set up with Slic3rPE to generate gcode for 5 different calibration prints that I use in the 3 materials (PLA, PETG, NGEN) I use for each of the 9 nozzle sizes I use. It's not art, but I can generate my little calibration library in about 5 minutes.

[...] wanted to repeat the first layer process, so naturally I went to the printer menu, and was disappointed to see that I will need to switch filaments just for that.I use the "life adjust" procedure for Live-Z calibration whenever I change nozzles or do a firmware update. It's based on using a 75x75mmx0.20mm print for 1st layer calibration, and is a lot easier to use & understand than the official on-board routine. If it's helpful, I'd be happy to share pre-generated gcode in whatever size and material you're after.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 27/12/2018 7:44 pm
ami.l
(@ami-l)
Eminent Member
Topic starter answered:
Re: Why is first layer calibration limited to PLA only?

I just printed the live adjust pattern from the link you provided, and oh man!!!
What a difference it makes. Amazingly simple and effective.

I think Prusa should replace their calibration pattern with this one, and save people the frustration and wasted material as a result of improper Z calibration.
My initial setting based on their pattern was off optimal by about 0.2, and it was really hard to tell.

What a difference in the print quality now!

Thanks a lot for your help!

Posted : 27/12/2018 8:58 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: Why is first layer calibration limited to PLA only?

The 75mm square g code is unlikely to fit in the firmware. I have a subdirectory on my SD card containing the three life adjust my way files plus a 200mm square with concentric infill which I Use for adjusting the perimeters with bed level correction. A couple of laps is all you need...

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 : 28/12/2018 12:34 am
Mustrum Ridcully
(@mustrum-ridcully-2)
Honorable Member
Re: Why is first layer calibration limited to PLA only?

Joan, is your concentric infill 200 X 200 mm file up for download anywhere I would like to try it please.

cheers
r

Posted : 28/12/2018 12:56 am
bobstro
(@bobstro)
Illustrious Member
Re: Why is first layer calibration limited to PLA only?


I just printed the live adjust pattern from the link you provided, and oh man!!!
What a difference it makes. Amazingly simple and effective.
Yes, that one's a life saver.

I just remembered that I've put my PLA and PETG test prints up on my notebook page. You can download PLA and PETG gcode ready-to-roll:

  • Test_Part_1 (Normal) is a little puzzle piece I use to quickly check new settings. The parts should stack and a 5mm bolt fit through.

  • Live-Z_Small (Normal) is the 75x75 piece based on the "Life Adjust" method. Good for quickly re-calibrating Live-Z after a firmware update or a nozzle swap.

  • Live-Z Full (Concentric) is the big full-plate print with concentric fill Joan.T suggested. Good for checking overall bed level.

  • 20mm_Cube (Normal) is a solid 20mm cube. Useful for checking for elephant's foot and general issues.

  • 20mm_Cube (Vase) is a hollow 20mm cube, useful for calibrating extrusion rates. Extrusion widths are listed in the gcode.
  • My notes and disclaimers on 3D printing

    and miscellaneous other tech projects
    He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

    Posted : 28/12/2018 1:24 am
    Share: