<p>Found the issue with help here! My Z-axis homing height was not set - I set it to 4 mm but found that the Z movement is way off (actual Z movement is more like 15 cm!).</p>
<p>I will update to the latest firmware as suggested.</p>

CC BY-SA 4.0
2021-03-07T15:18:37.723Z
2021-03-07T22:00:26.780Z
2021-03-07T22:00:26.780Z
Gary Clarke
<p>I'm just getting started in 3D printing by rebuilding an old machine from scratch updating firmware etc. It is all wired up and I am calibrating and completing tuning before a first print.</p>
<p>I am having a weird problem in that when I click &quot;home X&quot; button in Pronterface, my dual Z axes steppers move in the +Z direction and crash. If I home Z via Pronterface, the Z-axis behaves correctly (moves in -Z direction until it bumps off the limit switch). I am using an MKS GEN L V1.0 board and Marlin v1.1.9</p>
<p>If I move thr Z-axis via Pronterface in the +Z direction, it moves as expected. Both Y and X axes also seem to work okay and respond to commands normally via Pronterface.</p>
<p>Sending a <code>G28 X</code> command also results in a Z-axis activation and crash.
Sending a <code>G28 Y</code> command has the same result.</p>
<p>Any ideas on how to resolve this?</p>

CC BY-SA 4.0
2021-03-07T05:53:21.043Z
Most likely a firmware issue. Marlin 1.1 is quite old. I'd suggest getting the latest Marlin firmware on it. I have a the same board as you and it came shipped with old firmware. It will also help to post your Marlin Config.
Artichoke
CC BY-SA 4.0
2021-03-07T07:03:37.837Z
It is normal to have some Z-activation when homing X and Y. This is to protect the nozzle from hitting the bed or anything printed on the bed. But a centimeter should be enough, like `#define Z_HOMING_HEIGHT  10`
dotswe
CC BY-SA 4.0
2021-03-07T08:13:06.063Z
Maybe you could post your configuration file on PasteBin and share a link in comments. If wrongly configured, others can copy relevant parts into your question and answer the question.
0scar
<homing>
Issue crashing Z-axis when I home X or Y axes
Gary Clarke
# Issue crashing Z-axis when I home X or Y axes

(Asked by: username_0 on 2021-03-07)

I'm just getting started in 3D printing by rebuilding an old machine from scratch updating firmware etc. It is all wired up and I am calibrating and completing tuning before a first print.

I am having a weird problem in that when I click "home X" button in Pronterface, my dual Z axes steppers move in the +Z direction and crash. If I home Z via Pronterface, the Z-axis behaves correctly (moves in -Z direction until it bumps off the limit switch). I am using an MKS GEN L V1.0 board and Marlin v1.1.9

If I move thr Z-axis via Pronterface in the +Z direction, it moves as expected. Both Y and X axes also seem to work okay and respond to commands normally via Pronterface.

Sending a `G28 X` command also results in a Z-axis activation and crash.
Sending a `G28 Y` command has the same result.

Any ideas on how to resolve this?

**Tags:** homing
> **Comments:**
> **username_1**: Most likely a firmware issue. Marlin 1.1 is quite old. I'd suggest getting the latest Marlin firmware on it. I have a the same board as you and it came shipped with old firmware. It will also help to post your Marlin Config.  
> **username_2**: It is normal to have some Z-activation when homing X and Y. This is to protect the nozzle from hitting the bed or anything printed on the bed. But a centimeter should be enough, like `#define Z_HOMING_HEIGHT  10`  
> **username_3**: Maybe you could post your configuration file on PasteBin and share a link in comments. If wrongly configured, others can copy relevant parts into your question and answer the question.  

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## 1 answers

### Answer by username_0 on 2021-03-07. Score: 1

Found the issue with help here! My Z-axis homing height was not set - I set it to 4 mm but found that the Z movement is way off (actual Z movement is more like 15 cm!).

I will update to the latest firmware as suggested.


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