Prusa i3 Build Plate Offset Issue......Please Help

I own the Electron 6th Gen Prusa i3 with the auto level sensor (mounted to the back of the extruder) and it has a 220mm x 220mm heated bed. I like to use Repetier Host with CuraEngine and have tried several other software packages and get the same exact issue that I'm about to ask.

Here is my problem, I have attached my Configuation.h and for the life of me cannot figure this out. Please don't tell me change the offsets, I NEED TO KNOW EXACTLY WHERE TO CHANGE THAT AND MAYBE WHAT VALUES. My problem is that the unit prints perfectly fine BUT it thinks the build plate is ahead of it. Confused ?? I have attached a picture to explain.

Also explain to me on the LCD screen it has a option to Home Axis (I understand that part) and an option to Set Home Offsets, when do I use that option ???

PLEASE HELP.

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D3

This is the section of the config file you need to change.

// Travel limits after homing
#define X_MAX_POS 220
#define X_MIN_POS 0
#define Y_MAX_POS 220
#define Y_MIN_POS 0
#define Z_MAX_POS 180
#define Z_MIN_POS 0

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it might look something like

// Travel limits after homing
#define X_MAX_POS 20
#define X_MIN_POS -20
#define Y_MAX_POS 200
#define Y_MIN_POS -20
#define Z_MAX_POS 180
#define Z_MIN_POS 0

You could probably measure exactly how much it needs to move, but I would just use Kentucky-windage to get it more or less in the right spot. I would also watch it very very carefully as its moving to make sure you dont break anything.

Another option is to simply move your end-stops until it homes right in the corner of the print plate.

that code block is lines 326 through 336

Quote
AudaciousTuddle
This is the section of the config file you need to change.

// Travel limits after homing
#define X_MAX_POS 220
#define X_MIN_POS 0
#define Y_MAX_POS 220
#define Y_MIN_POS 0
#define Z_MAX_POS 180
#define Z_MIN_POS 0

---

it might look something like

// Travel limits after homing
#define X_MAX_POS 20
#define X_MIN_POS -20
#define Y_MAX_POS 200
#define Y_MIN_POS -20
#define Z_MAX_POS 180
#define Z_MIN_POS 0

You could probably measure exactly how much it needs to move, but I would just use Kentucky-windage to get it more or less in the right spot. I would also watch it very very carefully as its moving to make sure you dont break anything.

Another option is to simply move your end-stops until it homes right in the corner of the print plate.

I tried this before I posted and didn't have any change in the actions of the printer

// Travel limits after homing
#define X_MAX_POS 220
#define X_MIN_POS -11
#define Y_MAX_POS 220
#define Y_MIN_POS -41
#define Z_MAX_POS 180
#define Z_MIN_POS 0

I guess I'll give it another try. I'm assuming that the negative numbers are from the 0,0 to the endstops of X & Y. Which the numbers above were in the manual homing section of the config and I took those and placed them in the above code, reflashed, and did a G28 and then a G29 but had no change. Do I need to power the unit down after flashing or something ?? I see that it resets itself.

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D3

Well, I finally figured out my issues and I'm posting the resolution so if anyone else has the issue it should help. I ended up changing a few of the Configuration settings which I can post my config if anyone is interested but the biggest problem was resolved with the insertion of an additional G-Code at the start. What I did is below:

G28 ; home all axes
G29 ; auto level
G28 ; home all axes
G1 Z5 F5000 ; lift nozzle

Adding an additional G28 made the printer home again after the auto level and then start the print directly from the center point, or it at least knew where the center point was located. So now all my prints are utilizing the entire build plate.

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D3