Input shaping for Z axis

[JonBr306]

Description

Extended ZV input shaping so it can be done in the Z axis enabling certain types of kinematics (Delta, CoreXZ and CoreYZ) to use ZV input shaping now. Some cartesian machines may also benefit from this.

Requirements

Input shaping enabled.

Benefits

Z Axis can now be input shaped.

Configurations

Enable INPUT_SHAPING_Z

Related Issues

• [FR] Support for Z-Axis Input Shaping #26474

[tombrazier]

I am happy with these changes. @JonBr306 collaborated with me and I have reviewed everything and done some testing. More testing would be desirable from those with printers that will most benefit like deltas and core*z.

[thinkyhead]

This is great work and perfectly maintains the quirky Marlin style for the added macros. Merging shortly!

[dbuezas]

A bit late to the party but I started tuning it and got some results.

Here's my procedure on a modernised Ultimaker 2.

1. Rough frequency tuning

• Set zjerk and acceleration fairly high
• Setting zhop:normal to 0.2mm in Orca Slicer
• Print some parallel lines
• Measure the spacing of the bumps
• frequency = first_layer_speed / bump_distance. In my case I got 22Hz

2. Rough damping factor tuning

• Configure zhop:normal and then print sequence: by object in orca slicer
• In printing by object G-Code*: M593 D{current_object_idx/49.0} F22 Z
• Printed this pattern:
  
• Found the one that looked best. It was D0.05

3. Final frequency tuning

• Same as damping but now with M593 D0.05 F{20+current_object_idx/49.0*4} Z
• The 18th from the bottom looked best (almost perfect!).

* Found the one that looked best. It was 21Hz

Final Damping tuning.

• Repeated the process with M593 D{current_object_idx/100.0} F21 Z
• Found the best. It was D0.03

Before and after

The bottom half with Z input shaping disabled, top half with it enabled and fine tuned. I'm very impressed!
This is a single layer, if this was a wall, the bouncing would have compounded. FANTASTIC WORK!

[dbuezas]

By the way, this effect was made obvious by having high zjerk, zaccel and zhop, which I can now keep as defaults. I believe this explains the elusive and sporadic holes in some places I had given up on fixing.
Also I always printed stuff as close as possible to the back of the machine to avoid bouncing. I think it will be less of an issue now.

[tombrazier]

Fantastic results.

[dbuezas]

I just realised This has improved my z-seams too!

[tombrazier]

I just realised This has improved my z-seams too!

That sounds interesting but I don't know what you mean by z-seams. Could you elaborate?

[dbuezas]

Given that your contributions include input shaping and lots of LA improvements, I bet you have optimised quality so much that you forgot what they were :)

I mean these: (not my image)

I assume the bouncing was making the beginning of extrusions (e.g on layer changes) uglier.

[tombrazier]

Oh, I wondered if that was what you meant but couldn't think why Z input shaping would help. But it's pretty obvious from that picture that the bounce is causing the narrow then wide print path. What a great additional benefit.

[dbuezas]

Exactly. The image is not mine, I should make a print myself with and without IS z enabled. It wasn't consistently terrible because I had my z accel and jerk so low, to reduce the bouncing.