G29 - Auto bed not starting centered, Software shows object front but prints it on bed backwards

Hi guys,

I am having an issue with my Makerfarm Prusa i3 "8" - Marlin Firmware, it might be a quick fix but here it is, I have also attached 2 pictures with drawings that can give a good idea of what's happening

1st Photo - After G28, when G29 starts it'll start from the top right corner. (Adjusting offsets?) or maybe someone created a video with a fix for this, Autobed starts from top and moves from right to left.

2nd Photo - One thing I noticed so if I'm using the software on Octoprint with the slicer plugin it shows the object, but I have to place the item backwards to print properly. (not sure if this is just software and if I use another piece of software it'll be different but from what I remember I always printed squared objects and it always starts from the top.

Thanks so much guys, I'll keep messing around with it later and can upload any g code startup scripts if needed, but maybe this sounds like I just need to home my bed and save configuration and that may just do it idk

Best Regards,

David

It sounds like you have your printer home position (X0 Y0) located at the back right of the bed, this is normally the X max Y max location.
It shouldn't effect the prints ,just as you said, it prints them backwards.
Where are your X and Y endstops located ?

Hey Obewan,

You helped me out last time (m500 and m501 commands) after changing offsets on marlin to take affect for perfect z height after auto bed level.

I attached two photos of where the x is located on (right of extruder) y is located (near the front bezel of the bed)

I think I was looking it up and found this post not sure if it'll help to put this in the conf_h file

---

INVERT_Y_DIR

or INVERT_X_DIR

on config_h

---

So I think that might be the solution obewan, if your using octoprint and you hit right on the arrow to move the X axis right it goes left, same goes for Y axis almost like your playing an airplane game lol.

Just messed around with the invert on config h file and it does work to invert it to move in the opposite direction, but as I hit home the end stops were on the other side so I had to quickly shut if off.

Changed the invert false/true back to what it was

If your X endstop is on he right hand side of the extruder, then that is set as a X max enstop, you will need to tell firmware to home to X max.
If the Y endstop is at the front of the bed then that is a Y max endstop , so tell firmware to home to Y max.

This should make X0 Y0 at the front left corner of the bed
If you click the right arrow in octoprint but the X moves the wronng direction, just revers the motor plug on the controlller. (turn off power 1st or you will damage the driver chip).
same with Y motor.

ps. It would be a lot easier to understand if the X endstop was on the left and the Y endstop was at the back, but its not essential.

Obewan so I switched the x motor and that worked but my endstop was in the other direction so I had to quickly shut if off, it's ok though I'll probably just leave it how it is, as for the G29 homing being off center I just went back in config_h and put the old values I had for Y offset and X and pushed m502 and m500 and my gcode script I reverted back to the older one I had and everything is good now.

I will need to tweak the Y axis a bit as it prints a bit far down causing the bottom of the bed to hit the motor below.

Thanks again for reaching out man and helping out I really appreciate it.

Quote
I switched the x motor and that worked but my endstop was in the other direction

just reverse the homing direction in config.h ie. -1 to 1

Nice I think I'm set obewan, thanks a lot man

Sorry I keep bugging you guys these 3d printers are a tweaking hobby, I'm playing with temps now hopefully I can finish this 8 hour print lol