Fan "Bounce" Cura 4.6.1

[chrisr 18]

I made a little utility which plots the fan speed versus layers from a GCode file. With the model in the picture (Bridge.png) Cura "bounces" the fan speed after the bridge completes (a bit like you might see in an underdamped system).

 

Y axis = fan speed (%)

X axis = Layer number

 

Yellow trace = fan speed %

Blue trace = averaged fan speed

 

It doesn't appear to affect print quality but probably it shouldn't be there. Or if it should, why?

(Printer UM2 with Olsson block, WIN 10)

 

.STL attached

Slice_Test_46.gcode

Edited May 23, 2020 by chrisr
Update printer type & o/s

[Torgeir 248]

Hi chrisr,

 

I will think this is kind of normal, -as the fan is a mechanical device that will be affected by such a "violent" acceleration.

 

Thanks

 

Torgeir.

[chrisr 18]

Hi Torgeir I agree,  but it's hard coded into the Gcode.

[Torgeir 248]

I did not reflect your model for sure, but this is a general thing all the time during printing. I have never tried to measure this "normal violent" acceleration/deceleration bu I am sure it is very hi..  🙂

 

Rgeards

 

Torgeir

[chrisr 18]

The graph is of the M106 (Fan speed) values versus G0 (Z) values taken directly from the GCode. The "bounce" is actually in the code.

[Torgeir 248]

That's clear up for sure, hmm...

I'm kind of slow today.

 

Torgeir

[Torgeir 248]

Good catch.

 

Torgeir.

[chrisr 18]

11 minutes ago, Torgeir said:

Good catch.

 

Torgeir.

 

Thank you 🙂