Drive mapping not quite working for mixing extruder setup

grabercars

@Danal said in Drive mapping not quite working for mixing extruder setup:

Most external drivers need a longer pulse width than Duet default. See doc for M569.

Of the two, the external driver is the one that's working though.

Danal

Ahhh... interesting.

I see you commented out the cold extrusion... that was my first thought.

Danal

What is a typical G0 or G1 command that would move the auger extruder?

grabercars

Is it allowed to skip the second board driver E1 in the mapping?

Danal, because of the way the 'Tool' is set up as mixing, it is treated like any extruder extrusion command the firmware does the mixing based on the M567 ratio.

But, this is my first attempt at a mixing extruder, so I've almost certainly fat-fingered something?

dc42

I don't see anything wrong with your config, except that a mix ratio of 1:1 would make more sense than 0.5:0.5. I suggest you check the wiring to the extruder motor.

grabercars

Ok, I resolved the issue by moving the E0 stepper to E1 connector and making the change for that stepper output 3 to 4 in the config.g file.

M569 P4 S1 ; physical drive 4 goes forwards
M569 P5 S1 T2.5:2.5:5:2 ; physical drive 5 goes forwards
M584 X0 Y1 Z2 E4:5 ; set drive mapping

It appears that you can skip a stepper driver P3 after defining the xyz motion steppers, but the extruder mixing stepper drivers have to sequential? E4:E5

dc42

No, they don't have to be sequential.

grabercars

@dc42 Well.... No worries. I'm just happy to get it working and to move on to my next issue, which is to figure out exactly how many steps/mm this big stepper puppy needs and what the actual mix ratio is supposed to be. The Cerambot documentation is thin, to put it kindly.

Thanks again for a really fantastic piece of configurable hardware.

Steve Graber

dc42

It could mean that the E0 driver is faulty, in which case you might want to ask for a replacement while the board is in warranty.

Ravs99

@grabercars Did you end up figuring out how to adjust your Steps/mm for your screw extruder. If so, would you mind showing me your process?

Thanks