All axis seem to be reversed and end switches are ignored

Hi Guys,

Sorry in advance for my noob questions.

When I hit the Z move button in Pronterface my Z-Axis goes up instead of down and vice versa. Not sure about the other axis' but when I hit e.g. X+ in Pronterface the extruder moves to the left.

This is a fresh build and I am now trying to get the configuration right. All motors move at least. But when I move them via pronterface and they hit one of the 3 end switches, they just ignore it.

There are confusing settings in Marlin 1.0.2 and I am also not sure if I need to reverse the motor connectors. Now black points towards the power connectors (back/green/blue/red).

Holger

Motors can be reversed by the firmware or turning the plug around, not sure that colours are consistent on different brands of stepper, but mine has red closest to the power connectors, except for the extruded which is the other way around.

The end stop setup in marlin depends on your exact version, but most i3 I have seen have x set to max, and y, z set to min. If you are on ramps then there are headers for min and max for each axis and you need to make sure you are in the correct one. If you press home on pronterface then it should go toward each of the end stops.

Hi,

Thank you for your reply!

I managed to get the axis' right through the settings in Marlin. My Endstops are x-min, z-max and y-min. I figured that out because I (finally) found a graphic showing that.

Now I am able to home X and Y. Also X and Y are calibrated - getting closer to print :-).

But when I hit the home for Z, both motors make a noise for 1 second and stop without moving. I am able to move Z up and down via the buttons on the right in Pronterface. So I don't see any electrical/mechanical issue and don't understand why that happens.

I have attached my configuration.h.

Any clues?

Holger

Looking at your configuration.h try change:
#define DEFAULT_MAX_FEEDRATE {300, 300, 5, 25}
to
#define DEFAULT_MAX_FEEDRATE {300, 300, 2, 25}

to reduce the feedrate of the Z axis

Also you have the Z endstop as a MAX endstop, if it's at the bottom it should be a MIN endstop.

Steve

---

My updated Instructable on our Prusa i3 Build
[www.instructables.com]

Hi,

It was indeed related to the rate Z moves. I had to change:

#define HOMING_FEEDRATE {50*60, 50*60, 4*60, 0} // set the homing speeds (mm/min)

to

#define HOMING_FEEDRATE {50*60, 50*60, 120, 0} // set the homing speeds (mm/min)

And you were also right with might Z endstop. I configured it as 'z-min' so I changed that in the configuration and also plugged the wires into the 'max pins' on the RAMPS board. Now I can home all axis.

A question that goes through my mind, is how does the printer find its default z-position to print on the bed? Do I configure this here with the maximum travel?

// Travel limits after homing (units are in mm)
#define X_MIN_POS 0
#define Y_MIN_POS 0
#define Z_MIN_POS 0
#define X_MAX_POS 205
#define Y_MAX_POS 205
#define Z_MAX_POS 200

The print will start relative to the home position.

The gcode from the slicing software will instruct the printer to home, then move to where it needs to be.

The MIN and MAX values are the total travel available to the firmware, and should be set to match the travel available on your particular printer.
Care should be taken to make sure these numbers do not exceed the travel of your axis to prevent damage. You should match these settings in the slicer program you use.