Second extruder steps in Marlin Firmware

Hi

As I know in Marlin, steps/mm, max speed, and acceleration for each extruder are the same. In other words, Marlin assumes both extruders are identical.

But in my case I have 2 extruders with different stepper motor specs...
First extruder motor have 200 steps per rev. (1.8 deg/step), and second extruder motor have 400 steps per rev. (0.9 deg/step).

Now I need to make the first extruder steps half the second one!

What can I do ?!!

remove a micostepper jumper on extruder 2... then the steps/revolution are the same

Edited 2 time(s). Last edit at 02/24/2015 05:48AM by Dust.

Thanks

There are 3 jumpers on each stepper!

Can you please tell me what jumper must remove?

[reprap.org]

15 seconds on Google answers questions.

well I make the assumption that the first extruder has all 3 jumpers on it so it doing 1/16 microstepping
so the second extruder needs to be set to 1/8 microstepping.

jumper Yes/No step size
1 2 3
yes yes no 1/8 step
yes yes yes 1/16 step

So you need to remove the 3rd jumper ie the blue jumper on extruder e1 in this image



And just checking the math for compleatness

extruder 0: 200 steps per revolution at 1/16 microstepping = 3200 steps per revolution
extruder 1: 400 steps per revolution at 1/8 microstepping = 3200 steps per revolution

Edited 1 time(s). Last edit at 02/24/2015 09:03PM by Dust.

Thanks you very much