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Original Prusa i3 MK2.5 & MK2.5S
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Strange issues after MK2S to MK2.5 upgrade
 
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Strange issues after MK2S to MK2.5 upgrade  

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Programmatic
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Strange issues after MK2S to MK2.5 upgrade

My printer has not been preforming very well since doing the upgrade. The combo of issues has been a nightmare to track down.

  • It's over extruding. My printer is at the default estep value and I have to bring the extruder multiplier down .85 (Even with prusa filamnet).

  • Layer adhesion has been horrible. I think I narrowed it down to low temps. I've had much better success cranking up the temperature 20-25C. (Same materials I used before the upgrade)

  • The extruder keeps clicking and produces a mess when I try to print .15m layers. This might be related to the heat as well.

  • The part cooling fan only works on the left side of the build plate and even then, it seems to be dying.

    • When I tried to print 0.15mm and extruder was clicking.

    What the heck is up with the over extrusion?!

    How do I verify my suspicions about low temp. If it is a low temp issues, do I need to buy a new thermistor?

    I'm going to upgrade to the R3 extruder. Going to replace the bad fan while I have it torn apart. What other maintenance things should I be looking out for during the upgrade?

    Posted : 06/03/2019 9:26 pm
    JoanTabb
     JoanTabb
    (@joantabb)
    Veteran Member Moderator
    Re: Strange issues after MK2S to MK2.5 upgrade

    Hi Matt..

    silly question,

    did you reload the correct firmware?

    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 : 06/03/2019 10:14 pm
    Programmatic
     Programmatic
    (@programmatic)
    New Member
    Topic starter answered:
    Re: Strange issues after MK2S to MK2.5 upgrade

    Not a silly question at all 😀 Running MK25_3_6_0_RAMBo13a_en-cz

    Posted : 07/03/2019 12:07 am
    Programmatic
     Programmatic
    (@programmatic)
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    Topic starter answered:
    Re: Strange issues after MK2S to MK2.5 upgrade

    I read that misaligned bondtech gears can cause over extrusion. Gears look fine to my eyes.

    Posted : 07/03/2019 7:07 pm
    Programmatic
     Programmatic
    (@programmatic)
    New Member
    Topic starter answered:
    Re: Strange issues after MK2S to MK2.5 upgrade

    Turns out default e step values changed for MK2.5

    // MK2.5
    #define DEFAULT_AXIS_STEPS_PER_UNIT {100,100,3200/8,133}
    // MK2
    #define DEFAULT_AXIS_STEPS_PER_UNIT {100,100,3200/8,161.3}

    My e steps are 161.3, not 133 :O

    Ran M502 (didn't know it was a thing until I started digging through the source code xD), looks like there are a few differences between MK2.5 default settings and what is written to my EPROM. Going to write the defaults to EPROM and see how it goes.

    I have never changed any values other than e step before. This tells me that my EPROM never got reset after upgrading to MK2.5. I wonder if there was a step in the instructions that I missed?

    That still does not solve my temp problem though. Although I need a method to verify it is indeed a temperature problem. Anyone have any idea how I can test it?

    Posted : 07/03/2019 7:59 pm
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