Z axis homing direction moves AWAY from endstop

[x_Carlos_Danger_x]

Geeetech Prusa i3 Pro W - Marlin 1.0.03 from this forum

Well I wanted to upgrade my dads wooden frame printer to aluminum extrusion frame since the wood was warping. Have everything print/printed and now something is not right with the firmware. My only modification to the printer was to move the z axis motors to the top of the frame to give me a little more room below. I figured I would just need to reverse the Z-axis direction and it would be fine.... printer was printing fine before.

I opened the config file and stock settings and INVERT_Z_Dir was false. Set that to true thinking this would just reverse directions. (Motors are top mounted, but z axis endstop is still at the base). After installing with the value set as true the z axis does move in the correct direction, G0 Z5 raises it 5mm above bed, but when I home the z-axis, the carriage moves upward not downward towards the endstop!! Both the x and y are fine. Moving them +5mm moves the carriage OPPOSITE of the homing direction which seems correct. For some reason +5mm in the z direction moves the carriage in the SAME direction (upward) as the homing direction.

I have read through as many posts as I can find and none have worked.

TLDR; after placing my z axis motors on top and leaving the endstop next to the bed and setting invert_Z-dir to true, my homing direction loves the same direction as raising the z axis by 5mm. Homing should lower not raise. Any advice? turning into a crappy surprise for my dads printer even if I base mounted the motors like before the homing direction is still wrong.

[William]

Hi, You can check if your z-axis limit switch wiring connection is correct.
Then enter M119 in the manual control of the Repetier Host to check the limit switch.
For details, please refer to this: viewtopic.php?f=17&t=60927
I hope this can help you.

[x_Carlos_Danger_x]

Thanks for the quick reply! Things I left out, board is a Gt2560, printer came with 1.0.04 but I can only find 1.0.03 on here. Printer has printed a whole roll just fine before upgrading firmware.

So I did switch the limit switch on the z and x axis and the x axis homed fine so I know the limit switch is good. I manually depressed all limit switches and sent M119 and console showed all were triggered :/

What confuses me the most is that the direction of movement when homing (G28 Z) is towards positive when it should be moving towards zero. All other axis are fine and invert_axis-dir works fine with them. I’m am really at a loss for what is happening

[William]

Hi, Can you provide specific videos and pictures?

[x_Carlos_Danger_x]

Yep I can when I get home from work. It’s a bit confusing to explain via text.

[x_Carlos_Danger_x]

so for images I’ll just post to imgur and put the link in here in a little bit what’s the best way for video? very noob question I know lol...

[_kaktus_]

Hello.


Proceed in the same way as with the pictures.