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life adjust Z - my way  

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JoanTabb
(@joantabb)
Veteran Member Moderator
RE: life adjust Z - my way

Hi Dustin, 
when you drag and drop an image in the text box, a window like this, should open

if you use the 'Link To' option, and choose, 'Media File', the image, should be able to enlarge, when clicked,
have you tried cleaning the build plate with dish wash detergent / dish soap and how tater, then washed the soap off with hot water, and dried with a clean, plain paper towel?

do not touch the build surface afterwards...

works for me

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 : 04/08/2019 9:16 pm
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 --
(@)
Illustrious Member
RE: life adjust Z - my way
Posted by: dustintinsley
Posted by: Tim

If users can't figure out how to post images on the forum, how can they figure out how to print with their MKX printer?

Both are documented equally well... aren't they?

I thought this forum, specifically this post, was to help users...... 😒 

It was a rhetorical post due to known issues with forum ease-of-use and hidden features that no sane user will ever figure out without hand holding.   It took months for us hard core users to learn how to use most of what we think should be defaults settings and features.  Like the LINK TO mechanism every new user skips, yet is essential for the forum to function properly.

Posted : 04/08/2019 9:27 pm
dustintinsley
(@dustintinsley)
Active Member
RE: life adjust Z - my way

Just cleaners with dish soap and giving it a try. Looks like that may help quit a bit from initial looks of the brim laying rather well....

Posted : 04/08/2019 10:26 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: life adjust Z - my way

a little Fairy Magic, perhaps?
;-D

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 : 04/08/2019 10:56 pm
dustintinsley
(@dustintinsley)
Active Member
RE: life adjust Z - my way

So, still can not get PLA to adhere. Frustrated, was gonna give up on it. Threw in some old PETG I had, and it adheres great. WTF?! Coming from an Ender3, and the opposite was true. PLA worked great, never could get PETG to work (hence, why I had a roll laying around). What is going on here? I have only tried the roll of PLA that came with machine, could it just be bad PLA?! I am so confused with this.....

 

Posted : 05/08/2019 9:18 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: life adjust Z - my way

PETG tends to stick too well, and gives problems removing models. 

If your Buildplate is scrupulously clean PLA SHOULD adhere...  but obviously it is not at the moment

Could you show us a picture of the PETG Square please, and a picture of the PLA mess?   
If possible, could we also see the underside of the test patch? 
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 : 06/08/2019 12:06 am
dustintinsley
(@dustintinsley)
Active Member
RE: life adjust Z - my way
Posted by: joan.t

PETG tends to stick too well, and gives problems removing models. 

If your Buildplate is scrupulously clean PLA SHOULD adhere...  but obviously it is not at the moment

Could you show us a picture of the PETG Square please, and a picture of the PLA mess?   
If possible, could we also see the underside of the test patch? 
regards Joan

Thanks! I am currently printing PETG model. Once it is done, I will print the model I was trying earlier in PETG and PLA and get photos of.both for comparison.

Posted : 06/08/2019 1:34 am
Jaunx
(@jaunx)
New Member
RE: life adjust Z - my way

I had similar issues with PLA adhesion.  After much frustration, I finally determined that my cheap Sam's Club Member's Mark 91% IPA contained impurities that would cause the PLA to lift.  After switching to a 99% pure IPA, my adhesion has been perfect.

Posted : 06/09/2019 1:22 pm
Chocki
(@chocki)
Prominent Member
RE: life adjust Z - my way

Back to first layer, I spent weeks and I mean weeks wasting my time trying to get a perfect first layer, I lost count how many times I re-levelled the print bed (I fitted springs to allow me to adjust the bed), but nothing could get me past a barely working first layer , and never a perfect thickness across the whole bed, there was always variation in the first layer, If held up to the light you could see how the print was thinner in some parts and thicker in others. The top surface would be shiny over part of it and matt over another part, this would ultimately affect the final top layer of printed items.

I had reasonable improvement with the 49 point mesh bed levelling, well before it became part of the official firmware, but still the variation occurred and I had to do as best as I could using the mesh bed levelling adjustments from the LCD screen to try and dial in a reasonable first layer. But I had seen other people with the mythical perfect first layer, so knew it was possible.

All this with the textured PEI sheet supplied with the printer.

 

Then I bought a flat sheet with smooth PEI, went through a complete setting up and mesh bed levelling process once!, and bam... Perfect prints, even prints, no dips or thin parts, the Z axis screws don't even twitch from one side of the print to the other, with the textured sheet they would always be moving a small amount, I had never seen a flatter mbl visualisation!.

So if you just can't seem to get a perfect first layer with a textured sheet, get yourself a smooth PEI coated spring steel sheet.

Once you have the printer set up with this sheet, use the textured sheet for PETG only and accept it will never be perfectly flat.

Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.

Posted : 17/09/2019 8:09 pm
Mr Moo
(@mr-moo)
Active Member
RE: life adjust Z - my way

If I run this calibration square I can get a loverly print, slight over extrusion and I do mean slight !

Much kudos to the OP  👍 

However, whenever I print anything the first layer is atrocious! Looks to be really under extruding. Gaps between each "line" of filament, the infill doesn't reach the perimeters but the prints finish just fine.

What am I doing wrong........

Posted : 22/09/2019 11:14 am
FarbrorMartin
(@farbrormartin)
Active Member
RE: life adjust Z - my way

Why is the print temp so high on this calibration print? It prints the square at 225 for PLA. Prusa default first layer for PLA is 215 , and even that is high compared to other recommendations of 195-205 or so.

Won't the much higher temp change the first layer properties? Or is the idea that you adjust your PLA profiles to print first layer at 225? 

This post was modified 5 years ago by FarbrorMartin
Posted : 30/09/2019 8:18 am
FarbrorMartin
(@farbrormartin)
Active Member
RE: life adjust Z - my way

Also, the flow for this print is set to 100, where as it defaults to 95 for the prints I get from PrusaSlicer.

This post was modified 5 years ago by FarbrorMartin
Posted : 30/09/2019 8:42 am
Chocki
(@chocki)
Prominent Member
RE: life adjust Z - my way

Personally I wouldn't use the g-code for this print, just the idea. You really just need a .stl of the 75mm square 0.2mm thick and slice it yourself. This will apply your settings which you will be using for your prints. If you get a good first layer with your settings, you will get a good first layer for any prints you carry out after you have sliced them.

Plus you can use the same .stl for PLA, PETG. TPU etc etc.

Use somebody elses G-code and there could be all sorts of unwanted codes in there that alter your extrusion multiplier, your amount of microsteps, your PID values and save these to memory. Temperatures and speeds may not be optimal for your printer and ultimately results may be different too what you should be getting and you will adjust your live-z settings to this which will be wrong for your normal prints.

 

The principle of Jeff Jordans Live-z setting is perfect, just the G-Code may now be not optimal as there have been many improvements and enhancements in Prusa Slicer since then, which may create slightly different G-code.

Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.

Posted : 30/09/2019 10:29 am
bobstro
(@bobstro)
Illustrious Member
RE: life adjust Z - my way
Posted by: @chocki

[...] The principle of Jeff Jordans Live-z setting is perfect, just the G-Code may now be not optimal as there have been many improvements and enhancements in Prusa Slicer since then, which may create slightly different G-code.

Jeff's idea was made back in the early dark days of the Mk3 experience when this sort of wisdom and simple approach wasn't common. Jeff's main innovation was using an actual single-layer print rather than the hard-to-interpret single line Live-Z method. Observing the 1st layer of the Prusa logo print can accomplish the same end. It's describing how to interpret the results that makes this thread so valuable. The gcode itself isn't all that crucial once you know the trick.

I agree that in general, you don't want to blindly trust 3rd party gcode. However, there is value in having "tested and known-good" gcode available for those unsure or new to 3D printing and/or slicers. I do think it would be a good idea for Prusa to give this method an official blessing and elevate it to to a full blog post with appropriate links so users can feel more confident in using the gcode. Checksums etc. would be a good idea.

I have sliced my own versions for different materials and nozzle sizes. Mainly, I wanted to get away from the annoying beeps! It was very educational early on to have Jeff's gcode to review as an example.

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 : 30/09/2019 1:57 pm
Chocki liked
Chocki
(@chocki)
Prominent Member
RE: life adjust Z - my way

@bobstro

Agreed, there should really be a PRUSA 1 layer test print with the released test models. Benchy, frogs etc are nice to test your printer and see something tangible for your work if you assemble yourself, but I don't believe that assembly is finished without first dialling in a proper 1st layer.

I find the printer test print is enough to get 'into the ball park' so to speak, but then a proper 75x75 1 layer print to get this fine tuned followed by a 5x5 or 7x7 squares print covering the full print bed size to see if any mesh bed levelling correction is needed. Get this part right and your well on your way to having successful prints every time.

Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.

Posted : 30/09/2019 3:43 pm
FarbrorMartin
(@farbrormartin)
Active Member
RE: life adjust Z - my way

@chocki

One thing I noticed about the gcode is that it has a "smarter" pre-print routine. It first heats the hotend to just 170, and then starts the calibration. During the calibration it heats up to the target temp (225). This means that there is less oozing of filament vs the prusa metod. It also makes a longer and better purge, which also decreases the risk of old filament pieces ending up in the print. With the PS gcode i have to manually clean up the nozzle in the few seconds between purge and skirt.

But maybe those things could be added to PS too

Posted : 30/09/2019 4:50 pm
bobstro
(@bobstro)
Illustrious Member
RE: life adjust Z - my way
Posted by: @farbrormartin

One thing I noticed about the gcode is that it has a "smarter" pre-print routine. It first heats the hotend to just 170, and then starts the calibration. During the calibration it heats up to the target temp (225). This means that there is less oozing of filament vs the prusa metod. It also makes a longer and better purge, which also decreases the risk of old filament pieces ending up in the print. With the PS gcode i have to manually clean up the nozzle in the few seconds between purge and skirt.

That's a variation on the "2 step" nozzle warmup code. You can easily add your own to PrusaSlicer by saving a custom printer profile with the appropriate startup gcode added. I've documented my version here

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 : 30/09/2019 5:42 pm
FarbrorMartin
(@farbrormartin)
Active Member
RE: life adjust Z - my way

Great! I'll have a look.

I tried to slice my own version of the test square, but PS insists on starting the layer in the top left which makes it harder to see what's happening. Is there any way to force a starting point?

Posted : 30/09/2019 8:19 pm
Chocki
(@chocki)
Prominent Member
RE: life adjust Z - my way

In Configuration Preferences, try ticking Auto-centre parts

Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.

Posted : 30/09/2019 8:22 pm
rosterloh liked
mondo
(@mondo)
Active Member
RE: life adjust Z - my way

I'm sure someone mentioned it already in this thread, but the firmware now supports a 7x7 mesh bed leveling option that has dramatically fixed my first layer issues.  My bed is obviously not level and the 3x3 mesh was not enough to correct it, but after enabling 7x7 it's very consistent.  

Posted : 20/11/2019 12:56 am
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