Rostock Delta goes back to 0-0-0 after every move or extrusion - happens also during print via USB or SD card

Hello everyone,

I have a strange problem with my Rostock Delta 3D printer (RAMPS 1.4, Marlin firmware). Homing works perfectly – the endstops are detected correctly and the delta kinematics operate smoothly. However, no matter whether I manually move the X or Y axis via the LCD display, control the extruder, or simply extrude filament: after each action, the printhead immediately jumps back to position X0 Y0 Z0. Only the Z axis works fine. This happens during manual operation on the LCD aswell as a print job is currently running, wich is ofcours not working because it stays in 0-0-0 and moves like a woodpecker.
In the delta section, the usual values for DELTA_HEIGHT, DELTA_RADIUS, etc. are also set. Firmware is Marlin 2.x, no modifications to the display menu.
In Configuration.h and Configuration_adv.h, I cannot find any GCode or menu entry that triggers automatic return movements.

Does anyone have an idea what could be causing this?
Could the cause be a faulty display firmware, a bug, or a rare firmware configuration?

Are delta kinematics parameters or travel limits especially important to prevent moves always jumping to zero?
Are there other settings in Marlin that could cause this behavior?

Any hints or solutions would be great – I’m stuck.

Thank you very much!

you have reformatted Configuration_adv.h

This obscures what changes you actually made as the entire file has changed.

Edit: after wasting a hour reformatting Configuration_adv.h It looks like no options where enabled or disabled from default

Edited 1 time(s). Last edit at 09/12/2025 11:04AM by Dust.

Im thinking you have a power issue (very common on ramps)

And the board it just rebooting, after a reboot it rehomes.

Problem solved:

The problem was the following piece of code in config.h:

Wrong for delta printer:
#define X_MIN_POS 0
#define Y_MIN_POS0
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE
#define Y_MAX_POS Y_BED_SIZE
#define Z_MAX_POS 200

correct for delta printer:
#define X_MIN_POS -X_BED_SIZE/2
#define Y_MIN_POS -Y_BED_SIZE/2 //Jan
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE/2
#define Y_MAX_POS Y_BED_SIZE/2
#define Z_MAX_POS 200

Thanks to everybody and especialy to Dust for the work.

Darn... I should have seen that


normally on a Delta it defined like this,

#define X_BED_SIZE ((PRINTABLE_RADIUS) * 2)
#define Y_BED_SIZE ((PRINTABLE_RADIUS) * 2)

#define X_MIN_POS -(PRINTABLE_RADIUS)
#define Y_MIN_POS -(PRINTABLE_RADIUS)

#define X_MAX_POS PRINTABLE_RADIUS
#define Y_MAX_POS PRINTABLE_RADIUS


Note provided configs are also missing #define BED_CENTER_AT_0_0