@deckingman Do you have any resources for tuning acceleration and jerk?

@gnydick said in Pressure advance calibration:

@Phaedrux the linear advance script does exactly the same thing as the pressure advance. The only difference is the layout.

The PA script stacks the layers so you look at the front of the model and look for the gradients to go away.

The LA script draws them side by side and you look for which line is most consistent in it's thickness.

That is the same test.

Is this script here somewhere?

@phaedrux I skimmed through that post, but was hoping there was something more user friendly like the linear advance gcode generator.

I want to share some of my experience tuning pressure advance. It was mentioned that you will need to recalibrate retraction.

I'm using a bowden tube setup and at higher speeds (100mm/s) I was missing material at the start of extrusion. Increasing prime amount would fix the higher speed problems but leave blobs at lower speeds (25mm/s). To resolve this I had to reduce the retraction distance. I ended up with retractions similar to a direct drive and no extra prime amount. I ended up with the following retract and pressure advance settings:

M207 S2.0 R0.0 F3600 T600
M572 D0 S0.3

This is with the following setup:
E3D Volcano, 0.4mm nozzle
550mm Capricorn XS Bowden tube
Bondtech QR Extruder
1.75mm Amazon Basics PETG

Extruder config settings per request: (these are not necessarily limits of the extruder)

M350 E32:32 ;microstepping
M92 E953:953 ;steps/mm
M906 E900:900 ;motor currents
M201 E1000:1000 ;accelerations
M203 E3600:3600 ;maximum speed
M566 E900:900 ;maximum jerk speed

Before Tuning these settings I was printing slower (50mm/s) with 6.5mm retraction distance.

I was able to confirm this works as expected.

As always thanks for the quick reply. This is what I was hoping for, but just to double check if I were to add the following to my start script:

G10 L2 P2 X50 Y50 Z0 ; set offsets for coordinate system G55, sets G55 origin at X50Y50Z0
G55 ; Use coordinate system G55

I should expect the toolpaths to shift 50 in X and 50 in Y, but system macros will go to the same physical locations as if the G10 and G55 weren't present. So the G54 and G55 I added to system macros can be removed.

Does G28 also behave as expected? Using the offsets above, If I home in G55, then command G1 X0Y0, then command G54 the coordinates should display X50 Y50 and the physical location is the same as commanding G54 G28 G1 X50 Y50?

I'm curious how the G1 R1 works with pause, resume, and multiple work offsets. First a little background info. I am using a slicer for work that will only locate the part at the origin, but this is undesirable so I want to use work coordinate systems to offset the origin. I have to be able to switch back to machine coordinates when pausing and doing tool changes. I have been able to get this to work by using G10 L2 P2 X Y Z and then inserting G54 and G55 in my macros. For example, before the move to the tool change or pause position I put a G54, and on tpost or resume I put a G55. Is the G55 necessary? Will the G1 R1 return to the correct work coordinate system?
I'm not really sure I need to use more than one work coordinate system, but I am curious about the capabilities of this.

I want to share some of my experience tuning pressure advance. It was mentioned that you will need to recalibrate retraction.

I'm using a bowden tube setup and at higher speeds (100mm/s) I was missing material at the start of extrusion. Increasing prime amount would fix the higher speed problems but leave blobs at lower speeds (25mm/s). To resolve this I had to reduce the retraction distance. I ended up with retractions similar to a direct drive and no extra prime amount. I ended up with the following retract and pressure advance settings:

M207 S2.0 R0.0 F3600 T600
M572 D0 S0.3

This is with the following setup:
E3D Volcano, 0.4mm nozzle
550mm Capricorn XS Bowden tube
Bondtech QR Extruder
1.75mm Amazon Basics PETG

Extruder config settings per request: (these are not necessarily limits of the extruder)

M350 E32:32 ;microstepping
M92 E953:953 ;steps/mm
M906 E900:900 ;motor currents
M201 E1000:1000 ;accelerations
M203 E3600:3600 ;maximum speed
M566 E900:900 ;maximum jerk speed

Before Tuning these settings I was printing slower (50mm/s) with 6.5mm retraction distance.

@phaedrux I skimmed through that post, but was hoping there was something more user friendly like the linear advance gcode generator.

@deckingman Do you have any resources for tuning acceleration and jerk?

@gnydick said in Pressure advance calibration:

@Phaedrux the linear advance script does exactly the same thing as the pressure advance. The only difference is the layout.

The PA script stacks the layers so you look at the front of the model and look for the gradients to go away.

The LA script draws them side by side and you look for which line is most consistent in it's thickness.

That is the same test.

Is this script here somewhere?

I messed with pressure advance for a week and got nowhere. I tried that generator also, no luck. I noticed more change adjusting accel and jerk settings.
I noticed when increasing the pressure advance, when the line became more consistent the speed was slowed down. I used this speed to run a test with no pressure advance and got very similar results.. So I'm still at the start of pressure advance tuning..

@phaedrux I was wrong. They stay in the graph after reboot. Very useful. I'm using it to monitor my chamber heater, and control the heater with the chamber heater air temp.

Thanks, Will do! I noticed after adding the virtual heater it shows up under extras along with MCU. It seems as though I will need to add it to graph every time I connect to the interface. Is that true?

@dc42 Thanks! After reviewing M305 again I see virtual heaters numbered 100, 101, ....

I will add to my config

M305 P100 X154 T"K" ; Set thermocouple type K for heater 1

I love how versatile this is!