@jay_s_uk

I kinda got what you meant. I tried using the following parameters and not It is not making noise anymore and works properly.

M915 X Y S5 R1 F1 H2  ; set sensorless homing

Do I need to put the same M915 at the end of my config.g after the endstop section? (instead of M915 X Y R0 F0)

Also, using a Biqu microprobe as Z sensor - Should I use the same parameters for Z axes such as D3 for stealthchop? Does my homez looks good:

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v3.5.8 on Tue Dec 10 2024 15:03:23 GMT-0500 (Eastern Standard Time)

; ################# Home Z Preparation ################

G91 															; Relative mode
G1 H2 Z5 F5000													; Lower the bed
G90	
var xCenter = move.compensation.probeGrid.mins[0] + (move.compensation.probeGrid.maxs[0] - move.compensation.probeGrid.mins[0]) / 2 - sensors.probes[0].offsets[0]
var yCenter = move.compensation.probeGrid.mins[1] + (move.compensation.probeGrid.maxs[1] - move.compensation.probeGrid.mins[1]) / 2 - sensors.probes[0].offsets[1]
G1 X{var.xCenter} Y{var.yCenter} F4000 ; go to bed centre															; Back to absolute positioning

; ################# Home Z Preparation ################

G30					 											; Probe a single point

@o_lampe

I'm sorry but could you please give me an example or explain a bit deeper what you're thinking about? I'm not sure to understand.

I agree with you, it was just an example of a "long extrusion command" in contrast to 1.2.

Thanks!

@dc42

I'm working at very low speed for now so I did not face this problem yet to be honest - but thanks for the tip.

So from what I understand, there is no way I can send 2 G1 commands in parallel to deposit with my different extruders? I know it sounds weird but I think it might be worth trying different ways...

About the processor, what would you suggest starting with?

PS: I'm not an OEM but I'm developing a new machine for research purposes. I don't know if it is of interest to you, but let me know if it is the case.

Thank you very much!

@dc42

I got it. And yes it is the kind of output I have from the slicer for the first extruder.

However, what I want from the second extruder is to deposit a specific length of material along the path. The only information I know is the total length (for example 4700mm). I had the idea of writing a short program that would distribute the length based on the number of move but this is not convenient as it would deposit the same length no matter how long the moves are. Also, the rate of extrusion is calculated to be the same as the printing speed as it is a continuous material.

That's why the ideal scenario would have been to send a long-distance command like G1 E4700 F300 in parallel to the regular commands. Any thoughts?

Thank you,

Timothee

@dc42

Thanks for your answer!

I'm running a printer on a Mini 5+ with 2 extruders mounted on the same carriage. The goal is to print both materials simultaneously but also independently (sort of an IDEX but with only one carriage). The reason behind this is that this is a bioprinter, and that both extruders deposit different material format. One is a gel and the other is a continuous material. So far I tried mapping both extruders on the same tool and control them through a mixing ratio. This is not convenient as I do not want both extrusion factor to be linked and rely on each other. I also tried having the extruders set to tools but the command at sent sequentially (which I don't want either).

Instead, I'd like to control the gel extrusion traditionally (through G1 E commands). In parallel, I'd like to send a long-distance command with the other extruder that would run in addition (at the same time) to the other gcode commands.

This is the reason why I tried mapping one extruder on a tool and the other on an axis, hoping I could use them both in parallel.

Here is an example (does not work as T2 G1 waits for previous T1 G1 to be completed)

T1 
G91
G1 E4700 F240 ; Long distance command to be ran in background

G90
T2 ; Run this with second extruder in parallel to the first long distance command
G1 E1.2
G1 E2.4
G1 E3.6
G1 E4.8

Thank you for your precious help!

Hey!

I'm bringing back my old problem about dual extrusion and mixing ratio.
As the lattest does not work, I had the idea mapping on of my extruder like a axis as it I'd it to behave as an endless screw. Do you think it is doable? How would you organize the Gcode?

Thank you!

@dc42 Worked! Thank you!

@GeoffVR6 @chrishamm

Hello,

I'm coming back as I tried using mixing ratios. It seems this technique is not working very well for my setup. Indeed, both of my extruder should work independently as they should be unrelated. One is a standard extruder but the other mainly acts as an infinite screw. Its speed should not be calculated based on the same parameters as the main extruder.

For example, in the scenario of a mixing ratio, when I change the extrusion multiplier, all E values are impacted and so are both extruders. No matter the ratio, they are impacted. However, this should be only true for the main extruder only (and not the second one).

So my question is how would you control an extruder as well as an independent infinite screw, knowing that both should run at the same time? Do you think mapping the second extruder as an axis would work?

Thank you.

@gloomyandy @jay_s_uk @Phaedrux

Alright, I found the issue, and you're all absolutely right. Apparently, when using absolute extrusion mode, an E value too small reset the extruder and so it comes back in its original position (before the command) which create retractation-like movements.

So I gave it a try. When E<0.1, it is more likely that it happens. When I use values like E0.2, it works without retracting.

@jay_s_uk Do you think I should remove M82 in my gcode?
@gloomyandy You're absolutely right, I just removed the G1 E-2 command at the end and stoped generating it.

@Phaedrux

What I want to do is preventing the printer to retract the filament during printing.
In my previous printer under Marling I had put a M209 command which would do the job blocking the retraction.
But since M209 is not enabled in RRF, the printer is retracting a small amount of filament at every G1 commands (motors briefly turns counterclockwise).

PS: my printer is not extruding filament but this is for the example.

Here is a sample of my gcode:

; - START GCODE -

M82 ; Absolute extrusion
G302 P0 S0 ; Allow cold extrusion
G28 ; home
G92 E0 ; Reset Extruder
G1 Z50 F3000 ; Move z up little to prevent bed scratching
G0 F600 ; set travel speed to first point
M207 S0 ; disable retract in Relative mode

G1 X20 Y30 Z3 F1000
G1 X20 Y180 Z3 F240 E2
G1 X24 Y180 Z3 F240 E0
G1 X24 Y30 Z3 F240 E2

; - END of START GCODE -


G1 F240 X438.02 Y1006.24 Z1 E0
G1 F240 X438.02 Y1023.2 Z1 E0.339338
G1 F240 X438.02 Y1040.17 Z1 E0.678676
G1 F240 X438.02 Y1057.14 Z1 E1.018014
G1 F240 X438.02 Y1074.11 Z1 E1.357352
G1 F240 X438.02 Y1091.07 Z1 E1.69669
G1 F240 X438.02 Y1105.21 Z1 E1.979472

; - END GCODE -
M140 S0
M104 S0
M107       
G91 ;Relative positionning
G1 E-2 F1000 ;Retract a bit
G1 E-2 Z0.2 F1000 ;Retract and raise Z
G1 X5 Y5 F1000 ;Wipe out
G1 Z10 ;Raise Z more
G90 ;Absolute positionning

G1 X0 Y0 ;Present print

@jay_s_uk So far I don't have any G10/G11 but I have M207 S0 and it is not working. It keeps retracting.