# Marlin v2.1.2.1 E-step Z bug?

**URL:** https://marlin.crc.id.au/forum/t/marlin-v2-1-2-1-e-step-z-bug/2019
**Category:** Bug Reports
**Created:** [7 January 2024 17:41 UTC](https://marlin.crc.id.au/forum/t/marlin-v2-1-2-1-e-step-z-bug/2019 "2024-01-07T17:41:03Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![CRAK](https://marlin.crc.id.au/forum/user_avatar/marlin.crc.id.au/crak/32/1040_2.png) [@CRAK](https://marlin.crc.id.au/forum/u/CRAK)
#### Post date: [7 January 2024 17:41 UTC](https://marlin.crc.id.au/forum/t/marlin-v2-1-2-1-e-step-z-bug/2019/1 "2024-01-07T17:41:03Z")

</div>

I have recently updated my printer’s firmware to Marlin v2.1.2.1.  
It is a custom config due to the non-standard config of my printer:

- Creality Ender 5 Pro (frame, XYZ steppers, display and power supply still original)
- Creality v4.2.7 board
- E3D Hemera direct drive,
- BL Touch
- Run-out sensor (HIGH when no filement present)

Customisation was limited to setting default\_envs in platformio.ini to board “STM32F103RE\_creality” and applying some neccessary changes in Configuration.h and Comfiguration\_adv.h. No other modifications to either the code or stored data.

In the past I haven’t paid much attention to dimensional accuracy, but I noticed that the regular XYZ calibration cube was 20,18mm in height.  
E-steps are defined as 80 for X and Y and **800** for Z, so I intended to change that in the printer’s configuration.

In Configuration \> Advanced \> E-steps I found that the 800 steps/mm for the Z-axis was reported, but when I clicked the navigation button to edit that, it showed **144.64** e-steps/mm! Doing the same for X and Y show no discrepancy.

I then consulted Printrun (Pronterface), where the `M503` command returned all the expected values.

Next I’ve set the new e step values using:  
`M92 X79.92 Y79.68 Z792.86`  
followed by the save settings command:  
`M500`

Command `M503` now indicates:

```auto
echo:; Linear Units:
echo: G21 ; (mm)
echo:; Temperature Units:
echo: M149 C ; Units in Celsius
...
echo:; Steps per unit:
echo: M92 X79.92 Y79.68 Z792.86 E393.00
etc.

```

After disconnecting the printer and checking the e-steps on the the display all looked good (and updated as expected).  
When I chose to enter the e-steps for Z though, it returned **137.50** e-steps/mm.

For the record: with the new settings the accuracy of an XYZ calibration cube is nearly perfect.

Does anyone else have this issue? Or can it be reproduced anywhere?

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<div class="post-metadata">

### Author: ![CRCinAU](https://marlin.crc.id.au/forum/user_avatar/marlin.crc.id.au/crcinau/32/1337_2.png) [@CRCinAU](https://marlin.crc.id.au/forum/u/CRCinAU)
#### Post date: [24 January 2024 13:31 UTC](https://marlin.crc.id.au/forum/t/marlin-v2-1-2-1-e-step-z-bug/2019/2 "2024-01-24T13:31:50Z")

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Hi, this forum is specifically for firmware found on this site.

If you’re compiling yourself directly from the Marlin source, you can try either:

Discord: [Marlin Firmware](https://discord.gg/PftT2VuWSP)  
Github Issues: [Issues · MarlinFirmware/Marlin · GitHub](https://github.com/MarlinFirmware/Marlin/issues)