Help needed configuring for two Z steppers

I downloaded Marlin firmware version 1.1.0 RC 8 and flashed this to my laserBot laser machine which has a MegaPi controller board. The laserBot is now working fine.

I have a 3D printer frame sitting in my shop not being used which is the classic i3 Prusa type with the dual Z axis stepper motors. I am trying to convert this into a laser machine by installing a MegaPi controller board and flashing the same Marln firmware RC 8.

I uncommented the line in config adv.h

Z_DUAL_STEPPER_DRIVER

...but got a compiler error: pins.h:449: error: 'E1_STEP_PIN' was not declared in this scope.

Does anyone know how to resolve this?

My understanding is that if I can enable a second Z stepper, the 4th (and last) remaining port on the MegaPi will work the second Z stepper. I have yet to test that theory however.

Thanks...

You might have to look in "pins.h" for your specific controller and check if the E1_.... definitions are there. If not, you can add them with the appropriate pin numbers.
Might be just a matter of renaming the pin definitions for the last stepper port.

Attachment shows E1_STEP_PIN is defined in pins.h ???

Are you sure to really have two stepper drivers for the Z-axis, not just two stepper motors using the same driver either in parallel or in series?

If you have two Z-motors but only one stepper driver, you should not set Z_DUAL_STEPPER_DRIVER.

I'm using the MegaPi and it has 4 ports to connect stepper motors to.

I'm planning on connecting 4 stepper motors: X Y Z Z

Four ports/four motors.

I just have to figure out how to configure the Marlin firmware for that.

"Attachment shows E1_STEP_PIN is defined in pins.h ???"

no it does not, its shows defining _E1_Pin as E1_STEP_PIN


Where did you get your firmware from?
I see you have set MOTHERBOARD BOARD_MB_MEGAPI_LBOT

but BOARD_MB_MEGAPI_LBOT is not a standard supplied board. (and google isnt helping)

You need to show us the pins for this board.
If its following the new style it will be a file pins_MEGAPI_LBOT.h or something like that
If its following the old style it will have one large pins.h with everything in their.

This file needs something like, but with pins for your board.
#define E1_STEP_PIN 36
#define E1_DIR_PIN 34
#define E1_ENABLE_PIN 30

make them the same as your port 4 pins

Edited 2 time(s). Last edit at 04/10/2017 10:18PM by Dust.

I got the Marlin firmware from gitHub. 1.10 RC8.

MegaPi board diagram is attached.

The pin file is: pins_MB_LaserBot.h (attached also)

Right so

add in the following into pins_MB_LaserBot.h

#define E1_STEP_PIN 5
#define E1_DIR_PIN 4
#define E1_ENABLE_PIN 59
#define E1_CS_PIN -1

uncomment from config adv.h

Z_DUAL_STEPPER_DRIVER

(this steals E1 and re assigns it as Z2)

cross your finger and compile.

Oh you probably need to set E steps/mm same as Z

ie #define DEFAULT_AXIS_STEPS_PER_UNIT {43.74, 43.74, 760*1.1, 760*1.1}

Edited 1 time(s). Last edit at 04/10/2017 11:27PM by Dust.

uncomment from config adv.h
Z_DUAL_STEPPER_DRIVER

You mean comment out, right?

no

make sure it is un commented, you want it enabled

ie "#define Z_DUAL_STEPPER_DRIVERS"

Yes I want it enabled. I had it already uncommented.

I'll give this a try.

Thank you very much for your help.

you should also find where your micostepping is set

M350 [reprap.org]

Make sure E is set the same as Z

I wonder if Marlin is able to run without any extruder driver?
enabling Z_dual_stepper_drivers, only adds a second z-driver behind the last extruder.
Can you set number of extruders to "0"?

edit: It seems, you can't set it to "0", so you might also have to change pin definitions for E0 to some unused pins and use the former E0 pins for E1 ( 2nd Z-stepper )

Edited 1 time(s). Last edit at 04/11/2017 03:17AM by o_lampe.

Yes Marlin can run without an Extruder. Recall I modified this RC8 to run a laser machine (the LaserBot).

For running a laser you sure don't have to set the #extruders to "0", because you only need X and Y.