# Feature testing: Z-axis input shaper

**URL:** <https://klipper.discourse.group/t/feature-testing-z-axis-input-shaper/24886>\
**Category:** Features\
**Created:** [September 20, 2025, 8:54pm UTC](https://klipper.discourse.group/t/feature-testing-z-axis-input-shaper/24886 "2025-09-20T20:54:01Z")\
**Posts on this page:** 1\
**Showing post:** 11

<div class="post-metadata">

**Author:** ![MRX8024](https://avatars.discourse-cdn.com/v4/letter/m/c37758/32.png) [@MRX8024](https://klipper.discourse.group/u/MRX8024)\
**Post date:** [September 21, 2025, 11:21am UTC](https://klipper.discourse.group/t/feature-testing-z-axis-input-shaper/24886/11 "2025-09-21T11:21:42Z")

</div>

I find this innovation useful, as it significantly reduces z-axis vibration. Even if you don’t use zhop constantly (and many do, and it takes up significant print time), any z-axis movement will now be faster without increasing vibration. A resonance test for the z-axis can help identify and fix problems on this axis.

Vzbot235, attached the adxl345 to the bed base frame via screw. I have a standard base made of 2020 profile and plastic, as is the entire z-axis.

I increased these parameters because the vibrations were not noticeable against the background noise, but I overdid it a little, I think it’s not a big deal.

```auto
accel_per_hz_z: 40
sweeping_accel_z: 100

```

> **Without shaping**
>
> ![Without shaping](https://global.discourse-cdn.com/free1/uploads/klipper/original/3X/b/4/b48d8c09ef535e131c51149f5b12932dd1438d89.jpeg)  
> [raw\_data\_z\_20250921\_132831.zip](https://klipper.discourse.group/uploads/short-url/lsgT5zlBSPkDoFuxFsXsAUdv1qM.zip) (2.9 MB)

> **With shaping**
>
> ![With shaping](https://global.discourse-cdn.com/free1/uploads/klipper/original/3X/4/c/4c91d05156ab73c047f672feb38bed95b566895a.jpeg)  
> [raw\_data\_z\_20250921\_133427.zip](https://klipper.discourse.group/uploads/short-url/9QIMafVYvs9Q0k9x8EfoYSlHgXA.zip) (2.5 MB)

> **With standard parameters and up to 200 Hz**
>
> ![Without shaping](https://global.discourse-cdn.com/free1/uploads/klipper/original/3X/4/8/489b467a4a3416091c56e8ef0f5507686bbc8a7a.jpeg)  
> [raw\_data\_z\_20250921\_130933.zip](https://klipper.discourse.group/uploads/short-url/81UfgRBNDV74fS36pXFCSemGa4V.zip) (5.5 MB)

I think we have several resonances due to the transition nodes. The bed is driven by two trapezoidal screws through Oldham couplings, and then they are connected by a ring belt to a single motor.

Overall, I don’t think you even need to run a resonance test; the mere existence of the 3hump shaper at around 80Hz will dampen almost the entire range, and rounding is probably not important on z-axis. Do you have any comments on this, Dmitry?

If you need to test something else, let me know, I don’t plan to move away from this functionality, and the adxl will probably hang on the bed for a long time.

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