First layer adhesion issue  

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joshua.r4
(@joshua-r4)
Active Member

Hi everyone, I'm having a slight problem with my Prussian i3Mk2. I built the kit a few weeks ago and worked through the issues to get it calibrated. I got 6 good prints out of it but then started having issues with prints coming off the bed before they were done printing. I made some adjustments and recalibrated, thinking some parts may have shifted after break in. I finally got the calibration code to run cleanly and tried to run some prints. Now I'm having an issue where the print does not stick to the bed for the first 1 or 2 seconds. It drags along with the nozzle and ends up out of place. I am going to attach some pictures.

Can anyone give me some advice on how to fix this?

Posted : 17/09/2017 10:26 pm
joshua.r4
(@joshua-r4)
Active Member

I just pulled the print off and noticed some pretty significant curling on the bottom layers too

Posted : 17/09/2017 10:29 pm
aaron.s5
(@aaron-s5)
Noble Member

You need to set your Live Z correctly. The steps to do that can be found here:

http://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/-before-you-ask-troubleshooting-video-updated--t472.html#p39190

If that does not help, please comment back here and we can see what we can figure out.

Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…...
Posted : 17/09/2017 10:43 pm
joshua.r4
(@joshua-r4)
Active Member

I have tried adjusting the Z axis without much improvement. How close should the print head be to the surface? It seems OK when I run the calibration V2 code that came on the SD card.

Posted : 18/09/2017 1:43 am
aaron.s5
(@aaron-s5)
Noble Member

Unless you are very familiar with 3D printing, the V2 Calibration file is very hard to evaluate. Especially for beginners.

That is why the other method was developed to help make it more obvious and more accurate.

The Live Z adjust is designed to calibrate the printer so the actual position of the nozzle is known by the printer. Instead the printer knows the PINDA heights, but it needs this calibration to correctly know where it is.

When the printer thinks the head is at 0.15mm (e.g. after a home) it should be 0.15mm above the bed. For a typical first layer of 0.2mm, it should be 0.2mm above the bed.

If you follow the instructions I pointed to, you will be able to set it approximately correct, and then VERY accurately correct.

With a good Live Z, the filament is squashed to the bed at the correct thickness, and you have very good adhesion. Your pictures show that you do not yet have it correct.

The first layer is all important. Please try those steps.

Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…...
Posted : 18/09/2017 2:18 am
joshua.r4
(@joshua-r4)
Active Member

Ok, I will try it again. Thanks for your help.

In the meantime, I got it printing but the first layer has some bubbles in it. Is the head still too high or is it possibly a filament issue?

Posted : 18/09/2017 2:28 am
joshua.r4
(@joshua-r4)
Active Member

Thank you so much for pointing me in the right direction. I followed the directions and it came out very well.

One last question: why does the print look like it has bubbles in it? They are perpendicular to the direction of the extruder. Hopefully you can see them in the attached picture.

Posted : 21/09/2017 4:36 am
joshua.r4
(@joshua-r4)
Active Member

OK, after looking at it I found that it was overextruding. I backed off the Live Z and finally got it smooth. Looks like it's ready to go!

Posted : 21/09/2017 5:41 am
Nomad965
(@nomad965)
Trusted Member

Question, your printing from a specific app or just from the sdcard, this will make troubleshooting easier to figure out.

Prusa i3 MK2s MK2.5s Mk3 Mk3s BearPrusa Zaribo 320 - Kit Build - Rc Driver - Tweak freak...
“I know nothing about surpassing others. I only know how to outdo myself.” -Bushido-...
Posted : 30/09/2017 10:08 am
joshua.r4
(@joshua-r4)
Active Member

I am printing from the SD Card. I am using the Slcer program that was included. I have printed objects from the included files, from download sites (Thingiverse, Pinshape, and others), and a few of my own design.

Posted : 01/10/2017 6:29 pm
jan.p18
(@jan-p18)
Trusted Member

My experience with ABS adhesion is to slow down the first layer to 30% speed. Then it is OK.

...
Posted : 03/10/2017 8:04 pm
Nomad965
(@nomad965)
Trusted Member

Your Z is not set correctly, first set your Z so you get clean levels as much as possible, then run your finger across the surface, if the surface feels rough like micro ridges, decrease your extrusion till those ridges are gone, also make sure that your first level is fully sealed and flat to the print bed when you peel of the plastic see the print lines joined cleaned and no gaps.

Repeat the process till you perfect it.

Prusa i3 MK2s MK2.5s Mk3 Mk3s BearPrusa Zaribo 320 - Kit Build - Rc Driver - Tweak freak...
“I know nothing about surpassing others. I only know how to outdo myself.” -Bushido-...
Posted : 04/10/2017 12:41 am
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