Assembled MK2S - prints don't stick, or get torn off
 
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Assembled MK2S - prints don't stick, or get torn off  

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Tigra
(@tigra)
Active Member
Assembled MK2S - prints don't stick, or get torn off

I setup my pre-assembled MK2S and I've yet to get a successful print.

The issue I have is the print jobs get torn off by the print nozzle. If i do the v2 calibration the last line is dragged out of place when the print head moves back to its home position, thus ruining the prints

The Prusa logo print doesn't even make it past the first layer, the print gets pulled out of shape, and eventually gets ripped off either by the print head or that eraser head tipped part.

I tried some other prints such as Baby Groot model from Thingverse, those prints get ripped off too.

I've tried re-calibration in the settings, but it hasn't helped. I also made sure to clean it with alcohol as well.
I'm wondering if maybe the bed is messed up, I have a permanent marking on the bed where the Prusa logo had welded itself to the bed. (Note please don't ship these with prints stuck on the bed, it took me over an hour to pry off that print job with a fingernail}

So far I've spent over 6 hours trying to get my assembled MK2S working. I'me getting quite frustrated

Veröffentlicht : 04/06/2017 4:50 am
GertL
(@gertl)
Reputable Member
Re: Assembled MK2S - prints don't stick, or get torn off

Hi Rob

i would think that you need to adjust your live z. Have a look at below:

http://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/life-adjust-z-my-way-t2981.html#p34029

---
Gert

Veröffentlicht : 04/06/2017 9:59 am
JeffJordan
(@jeffjordan)
Mitglied Moderator
Re: Assembled MK2S - prints don't stick, or get torn off

yes, even so that your printer is pre-assembled, this doesn't mean that you don't have to do the required calibration procedures, like finding the correct live z adjustment value, proper pid calibration and extruder calibration.

dem inscheniör is' nix zu schwör...

Veröffentlicht : 04/06/2017 10:34 am
Tigra
(@tigra)
Active Member
Themenstarter answered:
Re: Assembled MK2S - prints don't stick, or get torn off

yes, even so that your printer is pre-assembled, this doesn't mean that you don't have to do the required calibration procedures, like finding the correct live z adjustment value, proper pid calibration and extruder calibration.

I went through the XYZ caligbration, and I have tried adjusting the live Z.

I don't understand about pid or extruder calibration. Can you explain? I remember moving the extruder axis at one point before I learned you can move z axis in order to gain access to below the print head to clean etx

Veröffentlicht : 04/06/2017 6:18 pm
JeffJordan
(@jeffjordan)
Mitglied Moderator
Re: Assembled MK2S - prints don't stick, or get torn off

...I don't understand about pid or extruder calibration. Can you explain? ...

doing the pid calibration is quite easy. simply look inside this thread. unfortunately the pid calibration, that you can access through the calibration menu, implemented in the actual firmware is not very accurate... so i recommend the described way with at least 8 heat-up cycles.
extruder calibration is a little bit more tricky, it was once implemented in an alpha version of firmware 3.0.10 but withdrawn short before release. but you can search the forum for the 10cm trick. with the correction factor you can calculate that way, you can either:

- set the extrusion inside your slicer to the required value
- use the "tuning" during the print to adjust the extrusion value
- recompile the firmware with a value that suits your assembly (especially determined by the effective diameter of the hobbed pulley).

usually the printer is somehow underextruding, because most of the hobbed pulleys are manufactured a little bit smaller than designed... so your correction factor will probably lie between 1.00 and 1.10.

dem inscheniör is' nix zu schwör...

Veröffentlicht : 04/06/2017 6:36 pm
Steveps3
(@steveps3)
Active Member
Re: Assembled MK2S - prints don't stick, or get torn off

Have you made sure that your bed is clean? Use one of the alcohol wipes that came with the printer to give it a good scrub.

Veröffentlicht : 05/06/2017 8:45 am
jonnieZG
(@jonniezg)
Trusted Member
Re: Assembled MK2S - prints don't stick, or get torn off

  • Use isopropyl alcohol with clean paper tissues to wipe the heatbead thoroughly clean. Do not touch it with fingers afterwards.

  • Adjust live Z to have the first layer more squished (increases contact surface), as Jeff suggested

  • Double check that you've selected a proper material in your slicer, so the bed temperature is right for your material.

  • Try using a different filament.
  • Generally, even when I print objects with a large contact surface I like to use at least 2 mm brim or 2 loops skirt, so the nozzle gets properly cleaned and the filament stabilizes extrusion rate.

    Veröffentlicht : 05/06/2017 9:59 am
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