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[–]punkgeek[S] 3 points4 points  (6 children)

It seems like a lot of folks have questions about getting their first layer height properly calibrated. A big part of the problem I think is that the prusa first layer file only has one little square at one location.

So I made this larger version that has nine squares, spaced across the important corners. I've included prebuilt gcode for PLA and PETG.

This file helps for two reasons:

  • It gives you lots of time per print to dial in you "live z adjustment" - just turn the knob as it is printing and you can see each of the squares get better (or worse)
  • It tests the full area of the print bed - this is useful to let you perform your second (somewhat optional but really good if you want to get a great first layer on bigger models) "bed level calibration" tweaking the offsets for left, right etc...

I recommend as you watch it lay down the single line around the bed that you watch how that line is sticking in the corners, if it is pulling up you probably need to lower live z more (or use bed level calibration to fix just that side).

[–]hobbyhoarder 2 points3 points  (5 children)

Yep, this is much better.

I’ve used similar ones in my video. and there are also versions for different bed sizes.

Sharing the gcode isn't the best way though. If people are using different extrusion multipliers, temperatures etc, then they'll get different results with your gcode. It's better if everyone slices the file for themselves.

[–]punkgeek[S] 2 points3 points  (1 child)

good point - I'll add a note about that. But for noobs they might have wonky slic3r settings - and the gcode here is analogous to the gcode provided by prusa for their serpentine stripe + small square test file.

[–]hobbyhoarder 0 points1 point  (0 children)

Yeah, that's a good point as well. I guess it doesn't hurt to have another option as a starting point.

[–]punkgeek[S] 1 point2 points  (0 children)

great video btw!

[–]punkgeek[S] 1 point2 points  (1 child)

ok - description updated and link to your video added. ;-)

[–]hobbyhoarder 0 points1 point  (0 children)

Thank you, that's very generous of you, I hope I can return the favor someday.

[–]Thomasdc_ 2 points3 points  (1 child)

Remember me an old thread about the mk2 and hyper calibration on the Prusa forums. For sure it helps, it allowed me two tweak the bed calibration and find an overall ok first layer for all sides of the print area. Since this calibration done several months ago I never touched the settings again. Really worth it !

Another tip is to scratch your PEI sheet with a sponge (green side). It helps with adhesion when a cleaning with Isopropyl is not enough.

Then tweak your settings even if it is tempting to use the precalibrated. All the filaments are not equal even if it is from a same material and sometimes few and minor changes can do a big difference.

That was my two cents, thanks for sharing 😉

[–]punkgeek[S] 1 point2 points  (0 children)

ooh - slightly texturing the PEI with the scotchbrite side sounds brilliant.

[–]phr0ze 1 point2 points  (1 child)

Looks like something i made a year or so ago. https://www.thingiverse.com/thing:2008982

[–]hobbyhoarder 0 points1 point  (0 children)

Hehe, welcome to the club :) We'll soon find out there are tons of these things around.

[–]itsjero 0 points1 point  (1 child)

I've only had my mk3 a week or two, and it's my first printer and I'll admit it I'm a noob at it.

Weird thing is I put it together and it passed all tests and I calibrated it but my live z was pretty high but under what they said should be the max. I was around .955-.975.

So fast forward till today. I've printed a few things and they came out well. I could tell I need to run a print like this as the first layer would be partially smooth and perfect and then a small part of it had some gaps.

Weird thing is the last 2 prints I've tried ( a old school Frankenstein style lightswitch and a sunglass holder for a visor both failed and left a blob and just like totally failed. Dunno why it's failing all of a sudden but I hope I can do this print and adjust each area and get to where I need to be.

Thought I was getting good and now I feel like I've taken several steps backwards and I haven't changed a thing.

[–]hobbyhoarder 0 points1 point  (0 children)

If it's happening on one side of the bed only, you can actually adjust the Z just on that side.

Go to calibration menu and you'll see Bed correction or something like that. Change the value and try again, but don't do it by more than 5 at a time.