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First layer, what is wrong?  

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crushfx
(@crushfx)
Eminent Member
RE: First layer, what is wrong?

I washed and washed and readjusted pinda and z to no avail. However, I am printing the whistle instead and more than 15 minutes and no problems. This makes me think the object lifts in case of prusa logo because the filament cools off. Which makes sense, the part that lifts is always the one not touched by the nozzle. In case of the whistle the entire area is covered by the extruder and very hot.

Whaddaya' think?

Napsal : 01/05/2019 9:36 pm
crushfx
(@crushfx)
Eminent Member
RE: First layer, what is wrong?

And here's the masterpiece 😎 that should verify that the printer was assmebled correctly, right?

Napsal : 01/05/2019 9:42 pm
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(@)
Illustrious Member
RE: First layer, what is wrong?

Layer 1 looks overly squished.  At 0.2 layer height, the skirt should be equally sized threads stacked on top one another, and the bottom of the whistle should look just like the top of the whistle... sans JP logo.

The Prusa part with large logo will print just as well using defaults (the included gcode file) - but requires the bed is clean.  Some large parts with flat solid bottom layers require the bed temp is raised, or corners will lift. Usually 70c is more than enough to hold PLA in place; other plastics are trickier.

But yes, the whistle looks good - except for layer 1.  

Adhesion is something we all fight. We all have learned the hard way keeping the bed clean is not optional, it is mandatory. Larger prints start adding to the problem: plastics tend to warp when they heat up and cool down: e.g., enclosures are required at some point to get higher temp plastics to print well. 

And each new model design brings new challenges.  It's best to think of FDM printing with home printers as an art form.

This post was modified před 6 years by --
Napsal : 01/05/2019 10:02 pm
Vojtěch
(@vojtech)
Honorable Member
RE: First layer, what is wrong?

What is the room temperature? Warping (and losing bed contact) may be a result of too cold an environment.

Napsal : 01/05/2019 10:50 pm
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(@)
Illustrious Member
RE: First layer, what is wrong?

Crush - here's an example of a part lifting.  It pulled the PEI off the metal in the process - leaving a blister. Room temp is always is 75f.  

This post was modified před 6 years by --
Napsal : 02/05/2019 4:33 am
Vojtěch
(@vojtech)
Honorable Member
RE: First layer, what is wrong?

@Tim: Wow. I've never seen that strong warping with PLA. ABS, sure, Nylon PA12, always, but seeing that PLAs with this level of thermal expansion exist is news to me. I must've been lucky with my materials.

Napsal : 02/05/2019 5:18 am
crushfx
(@crushfx)
Eminent Member
RE: First layer, what is wrong?

Maybe humidity is also at play? The ambient temperature at my place was also in the low 70F/20C. I wanted to raise the temperature of the printer but didn't know what values to set the nozzle and bed to.

Napsal : 03/05/2019 3:44 am
svein
(@svein)
New Member
Topic starter answered:
RE: First layer, what is wrong?

OP calling back in. Sorry for not responding earlier, but the original post was done in some desperation at the end of a long session, and I have not been able to check back in here until now. Thanks so much everyone for your informed input! From what I'm reading, I think I may have an issue with the PINDA being too low, thus making it difficult to get the nozzle close enough. I'll try to move it a bit up, so that I can have a lower (more negative) Z without it tearing into the print as it builds up in height.

And cleaning. Always the cleaning! 🙂 Thanks guys!

This post was modified před 6 years by svein
Napsal : 12/05/2019 3:39 pm
Peter M
(@peter-m)
Noble Member
RE: First layer, what is wrong?

First layer more heat in the extruder could help,

slower first layer could help.

 

And yes even with pla a glue stick could help, i printed a quare that lifts up, with glue stick it was OK.

 

of course clean bed,

try different filaments,

and first layer z offset is very important.

Napsal : 12/05/2019 4:22 pm
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