Ringing is only present while printing slow.

[MaxGyver]

@dc42 the ringing is also present when printing in open loop mode. I have a dual motor Y-gantry with 1HCL boards. So since dual axis closed loop tuning is not available. I had to kind of guess the correct values. I retuned my Motors on X and U which are shorter versions of the motors I have in Y. Since the same settings I have for X and Y cause some noise in Y I bumped up the P-Value from R=75 to R=125 and lowered D from D=0,2 to D=0,1.

But after lots of testing, I think there are two distinct issues at play. I found that the Y-Axis has some serious resonance caused by the motors. In open loop, the Y-motors cause a lot of noise and vibration, especially when thy Y-axis is moving slow. This explains the ripples that can be seen at the top of each half circle -> the resonance is most notable if the Y-Axis is accelerating from standstill or decelerating to a standstill. This resonance is most prominent while the axis is moving at roughly 40-100mm/s. I tried different belt tensions and even dampened the belts to ensure that the issue is not some resonance in the motion system. I read somewhere that altering the blanking time can alter the or even lower the motors resonance frequency?

The lower part was printed at 80mm/s the top at 30mm/s.

EDIT: while moving in circles both X and Y axis are quite noisy at low speeds and cause lots of vibrations. It is just much more obvious on Y-While printing. (the clicking/rustle is from the Bowden tubes)

https://photos.app.goo.gl/SxW5iy8HhZ5irayN9

[dc42]

@MaxGyver perhaps you are experiencing mid-band resonance?

You could try collecting data during a small part of the print using the input shaping closed loop plugin with the custom GCode option.

[MaxGyver]

@dc42 said in Ringing is only present while printing slow.:

@MaxGyver perhaps you are experiencing mid-band resonance?

You could try collecting data during a small part of the print using the input shaping plugin with the custom GCode option.

From what I have gathered, so far, most probably yes. Changing the motors on Y did bring a slight improvement as well as setting the holding current in closed loop mode to 100%.

I have the 3.4.1-b1 plugin installed, but other than the "custom" input shaper tab I did not find anywhere to put custom Gcode. I would like to run ad G2 circle and record the vibration at different speeds.

Cheers Max

[dc42]

@MaxGyver I'm sorry, I meant the closed loop plugin, not the input shaping plugin.

[IndeX4D]

@dc42
Any news here?
I have the same problem with a my Y-Axis. It has also 2 motors.

[MaxGyver]

@IndeX4D

I downgraded to RRF stable branch and upgraded again to unstable, after downgrading did not resolve my problem. I swapped the Y motors to cheap ones I got from omc-stepperonline. It fixed the vibration issue, but unfortunately, I don't know whether It was the Firmware upgrade or switching of motors.

I will investigate this issue further as soon as I have a little more time.

-Max

[IndeX4D]

@MaxGyver
thanks
I use also the stepper of stepper-online.
Can you tell me your timing and your motors or the PID tuning of the y axis motor?
Tuning is sadly still not available for double y-axis.
Richard

[dc42]

@IndeX4D said in Ringing is only present while printing slow.:

Tuning is sadly still not available for double y-axis.

The tuning move only moves the motor by a little over 4 full steps. Is that too much skew for your Y axis to handle? Alternatively, can you set the second motor to zero current while you tune the first one?

[IndeX4D]

@dc42
I think we got a little missunderstanding. I should describe it better....

´´Axis with > 1 drive will not show´´ so I can´t do a basic tuning in the plug-in.

[dc42]

@IndeX4D thanks for the clarification. If we enable axes having more than one motor in the closed loop plugin, and give you the ability to select which motor to tune, would that be of any use to you?

[IndeX4D]

@dc42
yes, that would be great.

After a few tests, it seemed to be better when Using different R I D parameters, so I´m positive that a good tuning solve this problem.
Other options may? - wrong Timing? What would you suggest?

Thanks Richard

[dc42]

@IndeX4D tuning one driver of a multi-driver axis is supported in the 3.5beta1 version of the plugin. We hope to release RRF 3.5beta1 later today or tomorrow.

[IndeX4D]

This post is deleted!

[IndeX4D]

@dc42
Very nice. thanks
Please tell us when it's uploaded. I'm waiting for it since the very first hour of the 1hcl

[IndeX4D]

This post is deleted!