Z Input Shaping

dc42

@Growlix when X and/or Y is moving the same input shaping is applied to all axes including Z. So you already have Z input shaping.

The more advanced shapers cover a wide frequency range (e.g. 3:1 for EI3) so you may be able to configure a single shaper that covers the major resonances of all three axes.

Growlix

@dc42 Interesting, I didn't realize it was being applied to the Z axis as well. I will experiment with different shaping parameters and see what happens. Thanks!

Kiolia

@oliof Deltas would likely want wildly different IS compensation for Z versus XY since Z is the one axis where everything's going the same direction, but assuming per-axis IS settings become a thing in RRF, there might be a case there!

chrismbp

Just adding for the record that this would be helpful for printers with large area beds. On my printer which is roughly 1x1x1m, I get a Z resonance that is similar to how a drum vibrates.

My solution now is go slow with Z motions, stiffen it up, etc.... But it would be nice to have a software firmware solution to help address this from the input side.

dc42

@chrismbp have you used an accelerometer to measure the frequency of the Z vibration? You may be able to use a single input shaper to handle the X, Y and Z resonances.

Notepad

@dc42 Is the InputShaper applied to the Z motors as well? I blindly assumed it was only on XY motors

dc42

@Notepad as mentioned in an earlier post in this thread, RRF applies IS to all axes.

Notepad

@dc42 Oh yeah. I see it now. I must have skipped that post. My bad.

chrismbp

@dc42 I hadn't taken a measurement from the bed previously. I just tried that out and you are correct, the EI3 shaper was able to cover the relevant frequencies for me on both the X/Y axes in addition to the Z resonance. There is some trade-off, but I will run some test prints next to see if the magnitude of the remaining vibration is worth worrying about.

dc42

@chrismbp thanks for your report.

We have the possibility of using separate input shaping for the Z axis in RRF 3.6 or later if it turns out to be useful.