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wrong DEFAULT_AXIS_STEPS_PER_UNIT in branch Marlin_UM_HeatedBedUpgrade


inx
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Posted · wrong DEFAULT_AXIS_STEPS_PER_UNIT in branch Marlin_UM_HeatedBedUpgrade

Hello.

Upgrading my ultimaker with a heated bed made me use branch Marlin_UM_HeatedBedUpgrade.

After some bad (z-compressed) prints i figured out the problem:

looking into Configuration.h where DEFAULT_AXIS_STEPS_PER_UNIT is defined i find the following:

#define DEFAULT_AXIS_STEPS_PER_UNIT {78.7402,78.7402,200.0,760*1.1}

steps per unit for z-axis: 200

while in branch "Marlin_v1" i find a different value for the z-axis:

200.0*8/3

which explains the "compressed" prints and my bent heated aluminium bed...

changing that value solved the problem.

The same value for the z-axis (200) is to find in branch Marlin_UM_Original_Plus.

is this intentional or just simply a mistake?

inx

 

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    Posted · wrong DEFAULT_AXIS_STEPS_PER_UNIT in branch Marlin_UM_HeatedBedUpgrade

    Did you upgrade with the UM made heated bed or a custom self built one? I believe the firmware you mentioned in git is for the UM made bed which comes with a different Z stepper and screw.

    If you build a custom heated bed than you should know two things... The mm per steps is 200 * 8 / 3 because the UM original without the bed upgrade has a screw with a 3 mm pitch, a stepper with 200 steps per rev and it is run in 8 microstepping mode.

    The second is that the UM made bed uses a PT100 temp sensor which your bed probably doesn't use. Flashing the UM firmware for the UM made bed onto a printer with a custom built bed and a different temp sensor causes problems in the firmware with MAXTEMP or MINTEMP errors and may make updating the firmware difficult.

     

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    Posted · wrong DEFAULT_AXIS_STEPS_PER_UNIT in branch Marlin_UM_HeatedBedUpgrade

    Indeed i use a non UM heated bed unsing a temperature sensor with 100kOhm

    Figuring out the Temperature sensor was quite straight forward and easy to find in the configuration file.

    Why would a heated bed change the Z stepping resolution? Well, maybe UMs heated bed comes with a new rod... i dont know.

    anyway, i think at least some comments in Configuration.h would nice to avoid that people use wrong values for the z-axis.

    a wrong value there can harm the machine...

     

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    Posted · wrong DEFAULT_AXIS_STEPS_PER_UNIT in branch Marlin_UM_HeatedBedUpgrade

    Yes indeed, UM Heated bed kit comes with a new Z axis, just as the UMO+

    The Marlin_UM_HeatedBedUpgrade branch is for the official UM kit.

     

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    Posted · wrong DEFAULT_AXIS_STEPS_PER_UNIT in branch Marlin_UM_HeatedBedUpgrade

    Well, i think the title of this post should be rephrased:

    "Attention when using branch Marlin_UM_HeatedBedUpgrade for custom heated bed"

    Nevertheless i think it would be a good idea to have some explicit comments about the values for DEFAULT_AXIS_STEPS_PER_UNIT in Configuration.h

     

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    Posted · wrong DEFAULT_AXIS_STEPS_PER_UNIT in branch Marlin_UM_HeatedBedUpgrade

    Hello Guys!

    I have a UMO and the new heated bed kit by ultimaker. I usually compile my own custom version of Marlin.

    There are a few things I would like to confirm:

    - the temperature sensor should be set to \\20 is the PT100 circuit found in the Ultimainboard V2.x

    - the steps per unit should be 200 and the microsteps should be set to 1/8

    Thanks in Advance,

    Antonio

     

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    Posted · wrong DEFAULT_AXIS_STEPS_PER_UNIT in branch Marlin_UM_HeatedBedUpgrade

    You only have to change the steps, the temperature sensor is not changed with the kit. You only get a PT100 with the UMO+.

    The official firmware for the UMO+HBK is https://github.com/Ultimaker/Marlin/tree/Marlin_UM_HeatedBedUpgrade, you can compare in GitHub the changes from the https://github.com/Ultimaker/Marlin/tree/Marlin_v1.

     

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    Posted · wrong DEFAULT_AXIS_STEPS_PER_UNIT in branch Marlin_UM_HeatedBedUpgrade

    Thank you!

     

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