Homing away from the heatbed

Hi everybody,

I'm finishing my wooden handmade Prusa i3 and could home for the first time this afternoon. However, due to the very rough work I did, on the Y axis, the hot end is about 4 cm away from the heatbed.

Is there any way in the configuration file to tell Marlin that the trigger actually represents -50 on Y, and that it should shift after homing ? I'm worried that my printer begins printing out of bounds.
I will replace a lot of parts in the future by printed ones in order to be able to use the whole heatbed, but in the meantime I don't care losing a little bit of surface.

Thanks !

Hi,

I am using a CoreXY configuration and have the X and Y home (min) set to a negative position.
Only set at -5, the reason was that I did this is that I found that setting it at 0 was that when you home the carriage it moves slowly until the switch (using a microswitch) makes contact, but when printing at speed I was getting a false switch activation as the switch arm gets flicked before the 0 position.

Don't know if there is a limit to a negative amount.

Cheers

Marlin- configuration.h

// Travel limits after homing
#define X_MAX_POS 205
#define X_MIN_POS -5
#define Y_MAX_POS 205
#define Y_MIN_POS -5
#define Z_MAX_POS 180
#define Z_MIN_POS 0

I've tried this, but Pronterface still goes in these zones that I want to eliminate when I move the motors. Or is it only when in manual, and will avoid them when actually printing ?

I found Pronterface only goes to negative positions when homing (Home position set as a negative position). On manual moves with Pronterface Move (e.g. 0.1mm or greater) it moves out of the negative to the 0.1mm position and won't move back into the negative area again unless you do a home.
Also you can't move into an area that's greater than what you have set in firmware as your max position.

Same thing happens when you send Gcode in Pronterface.


A couple of pics of my CoreXY machine.

Cheers.