First layer issues...  

RE: First layer issues...

Yes go negative, It looks like you probably need to go down another -50 to -100. Adjust your live adjustment Z height as it's printing and just keep your eye on it, you'll see when the print starts to change just take it slow so you don't run into the bed, you have a way to go! I usually adjust let it print 10 lines and then readjust if needed. 

RE: First layer issues...

Thanks , pretty good guess. I am at work right now, but I believe I settled at right around -0.625 +/- 0.012. I want to say the final offset was -0.613. This was on the smooth PEI sheet. I still have the textured and satin sheet to do.

Rusty

RE: First layer issues...

It appears that a further reduction of approximately -50 to -100 is likely necessary. Please make incremental adjustments to the Z height during the printing process and closely monitor the changes. Exercise caution to avoid collisions with the print bed, since there is still a considerable distance to cover. Typically, I initially set the printing output to display 10 lines and afterwards make any necessary modifications as required.

Posted by: @rusty-jones

I have been trying to dial my MK3S+  in to do MMU printing and thought I would start from presets. The following picture is of a first layer calibration test, a 4"x4" 1 layer print. As you can see it is very stringy, and the layer lines are not well connected. Am I correct in thinking that I need to lower my Z offset. It is currently -0.530. Should I make it more negative?

Thanks

Rusty

 6196bfa3-bad-first-layer.jpg  connections puzzle

RE: First layer issues...

 I have a 1.st-layer question too: guess, Issues with bed height -  can´t figure out, why my bed adhesion is near to zero between fresh PETG and structure sheet.

The plate is almost new, super clean and fat-free

Maybe you guys might tell me if I´m too far up or need to go more into Minus?

Pretty idea-less, as I don´t succeed since two days fixing it

RE: First layer issues...

You must get closer to the bed with your nozzle. Don't be afraid of high digit negative values. You can go up to -2000 (not sure at the moment if there is a decimal point in front of the value in the display or not and I don't want to switch on my printer just for this 🙂 ), if that is not enough, you'll have to adjust your PINDA probe and move it closer to the bed.

RE: First layer issues...

thanks all. 

that was not my print bed, but I again cleaned the hell out of it with hot water and dishcleaner) 

Here, photos:

(disclaimer: I'm dead-low, that low actually I already was too low and scratched my new plate - 

and still, no adhesion.)

The nozzle is tight-fit

RE: First layer issues...

So the printed strings of filament came loose by themselves? This is strange. For a correct calibration the whole of the printed filament should stick tight to the plate. And the final square should be tight and even.

RE: First layer issues...

very strange indeed...

printed several petg, which all came off. 

this happens constantly with this sheet (original prusa) - I really cleaned it perfectly, wiped it with isopropylalkohol too.

bed heated to between 70 and 85c

RE:

For PETG the default bed temps in PrusaSlicer are 85 °C for the first and 90 °C from the second layer. 70 °C is too low a temperature for PETG.

The 1st layer cal should ask you for the filament type and use the correct value for PETG. Did you watch the display if the temperature was correct during the calibration?

RE: First layer issues...

sure I did. I used whether Prusa"s Std PETG settings as-is or the settings recommended by the filament producer (one filament is rather head-sensitive, obviously) 

Yh, am aware a lil more heat on the bed is better,... 

RE: First layer issues...

sure I did. I used whether Prusa"s Std PETG settings as-is or the settings recommended by the filament producer (one filament is rather head-sensitive, obviously) 

Yh, am aware a lil more heat on the bed is better,... 

RE: First layer issues...

guys,

I now will call my new structure steel plate by Prusa a day... since I having it, everything changed to bad. Sadly, I already dumped my old, wasted smooth plate some time ago.

could you give me a tipp, please? 

I'm in desperate need of a new plate compatible with my Mk3s - best, available over Amazon.de or EU... 

I'm printing PETG mostly, seldomly PLA.

Thanks for your quick help. 

RE: First layer issues...

I used this texture steel plate for my MK3S+ (works with PETG) https://www.amazon.com/Quality-Double-Textured-Spring-Printer/dp/B07YYXC2B7/ref=sr_1_7?crid=2Y5UM265LXW9G&keywords=texture+steel+plate+for+MK3S%2B&qid=1696615216&sprefix=texture+steel+plate+for+mk3s%2B%2Caps%2C119&sr=8-7

I have no issue with that, but I don't know if it will be available in your country. 

RE: First layer issues...

I purchased an alternative steel plate, and it´s adhesion far better (still wondering, why the original Prusa-plates I used before were nice...).

Still, I was able to sort out a second issue:

When level via First Layer Calib I noticed the steel plate, even after fully redone Calibration maybe isn´t all flat anymore? It comes to my mind, as the leveling, especially at the front seems to be higher than in the middle

Possible?

thanks

RE: First layer issues...

@Kopplog,

I have some questions:

 we are in the MMU3 section of the forum, so I can image that you discover this issue printing the MMU3 parts.

- did you experienced issues with this plate before starting to work with the MMU3 or it happened just when you started to use the MMU3?

Just by chance I had a similar experience with my old steel sheet, but I figured that it was due to:

• When I dismounted the MK3S+ to install the new MMU3, I got the opportunity to install also a REVO nozzle.
• The Revo nozzle has its own concept of temperature, if you see 230° on the LCD in reality is 225° on the nozzle, but the filament is probably 215/222° and this cause adhesion problems. So on the REVO, if I want to print a material at 220° (ideally) I need to set the nozzle to 238° on the LCD.
• The steel sheet with the time lost adhesion, especially after months of hairspray that I used in the past. Now even after the perfect cleaning, probably the PEI has been damaged by the hairspray solvents and does not attach as in the past. The only option to use it, is to set its temperature at 60° for PLA, and print the PLA at high margin (218/220°).

I should say that I am using PRUSAMENT, and I can say that since the MK4 exists I think they have changed the ingredients to make the filament more fluid and ideal for MK4 hi-speed input shaper. I can see because in the past they never ever left a chemical mark on the plate, and now they left it. When I remove PLA parts, I always need to remove the ghost mark from the plate using isopropyl alcohol.