Anet A8 Z-Probe Bed Positioning going outside of bounds

I have an Anet A8 with the Anet 1.7 board, Skynet3d v2.3.2, and the stock sensor. I originally had this configuration with the stock extruder, but recently purchased an E3D v6 clone with a Bowden extruder. After installing a new bracket I had printed (TNS E3D v6 Bracket) with the adjustable stock sensor mount. I installed the extruder and sensor.

I knew I had to adjust sensor position. I went through the 3DStackExchange post on Z probe boundary limits as well, and added all of the end positions and probe to nozzle offsets (I will list below) to my Configuration.h file, saved, checked the changes were there in the Configuration.h tab in the Arduino IDE and uploaded the firmware. After this I went to hit auto leveling in the prepare menu, and the positions were different from the stock extruder and mount, but when it got to the third position, the sensor was off the bed, and the nozzle dug into the bed.

The configuration I was editing was from the Anet A8 5 button stock sensor Configuration.h file.

My probe is (When looking from the front of the Anet A8) forward and right of the nozzle.

• My Y-axis offset is -3 (the sensor is 3 mm in front of the nozzle when looking from the front)
• My X-axis offset is +37 (the sensor is 37 mm to the right of the nozzle when looking from the front)

The stock min_probe_edge is 10 mm, so with my math my Left Probe Bed Position is 47, Right is 210, Back is 207, and front is 10.

I want to get my probe settings properly set up so I get my bed leveling back and I do not want to ruin my bed while leveling.

• I have calibrated the bed center now, and it is on the bed now! I have also updated the x_min_pos to -10 which has now moved the nozzle and sensor to the positions I was expecting. Thank you for your help! Nov 30, 2019 at 8:50

If you have done major revisions to the printhead by changing to another carriage, it could be that the nozzle in the carriage is not at the exact position as in the previous carriage.

So, have you made sure that the new carriage has the appropriate values so that the nozzle is at (0, 0) when commanded to that position? Alternatively, in different wordings, this translates to: "Is the printer printing in the center?/Are the prints centered on the build plate?". See e.g. "How to center my prints on the build platform? (Re-calibrate homing offset)".

From the Thingiverse link van be read that this carriage requires an offset. The carriage design mentions a shift of the X axis:

#define X_MIN_POS -10


Is that working for you?

General remarks regarding the firmware update: Have you also loaded all values from firmware using M502 and then M500? (if M500 commands are enabled). Also, Skynet3D is obsolete!, use Marlin instead!

Do you have eeprom enabled? Because if you do, you can change configuration.h all you want but it's always gonna use the values from eeprom. I advise you to install repetier and change the eeprom values with that. Or maybe you can use the display if you have one.

• Ehm, if you alter config.h, you just have to reflash the EEPROM as explained here: M502 to overwrite the SRAM and then M500 to write SRAM into EEPROM. Dec 1, 2019 at 15:33
• Yes that can be done as well, but it is easy to forget if you're new to this. Dec 1, 2019 at 15:54