Sudden Z Offset Issue

Discussion in 'Calibration, Help, and Troubleshooting' started by Steven Burns, Jul 31, 2017.

  1. Steven Burns

    Steven Burns Well-Known Member

    Joined:
    Sep 4, 2015
    Messages:
    195
    Likes Received:
    55
    I was doing a print today and the part lifted and started to get dragged around. Happens from time to time and no big deal. I selected to stop the print on the LCD and now the nozzle is about 4mm off the bed and I cannot get it to reset.

    The sensor appears to be working, it is not dirty and did not get bumped at all during the process. I tried to go through the setup process again, but with the hybrid extruder mount it is not the same as the original 1.0 mount.

    The z offset in the Motion menu stops at -1 and I can only tell the bed leveling to go down -4, but that is still not enough.

    I have reflashed the firmware, cycles the machine a dozen times and have even tried to move the bed up manually by turning the lead screws. When I do that I get an "ERR: Too Far" message on the screen and then when I home it goes right back down.

    I have never had this happen to me and I print all the time.

    This is the first print, Pro Single Extruder with Titan, that I have tried to Simplify3D Version 4, but I cannot see how that would have anything to do with homing.

    Any ideas as what might be causing the issue and how to resolve?

    Thanks
     
  2. Old_Tafr

    Old_Tafr Well-Known Member

    Joined:
    Mar 7, 2016
    Messages:
    560
    Likes Received:
    75
    I don't have quite the same setup, Dual 1.0 BB, but looking at the commissioning page..

    https://wiki.e3d-online.com/wiki/Printer_Commissioning

    Step 4.2.1 (Pro and All Hybrid Extruders)

    There is a note to say

    IF YOU HAVE ALREADY BUILT YOUR PRINTER AND YOU ARE FOLLOWING THIS PROCEDURE TO (RE) COMMISSION THEN YOU WILL NEED TO RESET THE DATA ON THE RUMBA, (OTHERWISE Z-AXIS CALIBRATION ETC WON'T WORK) BY SELECTING ................Restore failsafe.

    Could it be that you need to do this reset? Although you do say you have re=flashed the firmware which would I assume have the same effect............ but worth a try selecting Restore failsafe.
     
  3. Steven Burns

    Steven Burns Well-Known Member

    Joined:
    Sep 4, 2015
    Messages:
    195
    Likes Received:
    55
    I did a restore failsafe before and after re flashing the board and it did not appear to do anything at all. I re-homed after trying each step and nothing seemed to work.

    From what I can tell, it looks like the sensor is tripping too soon or that the board will not let me adjust for the offset from the sensor to the tip. If I can just get this to stick than I will be back to normal.
     
  4. Old_Tafr

    Old_Tafr Well-Known Member

    Joined:
    Mar 7, 2016
    Messages:
    560
    Likes Received:
    75
    Can you go back to the earlier step where the fan(s) are move to calibrate the sensor, or is this the step you are at?
     
  5. Steven Burns

    Steven Burns Well-Known Member

    Joined:
    Sep 4, 2015
    Messages:
    195
    Likes Received:
    55
    That is where I started, but even trying to set the z offset to -5 did not work as it will only go to -4mm.

    I'll see what I can do when I get home and start the process over.
     
  6. Old_Tafr

    Old_Tafr Well-Known Member

    Joined:
    Mar 7, 2016
    Messages:
    560
    Likes Received:
    75
    Who knows what is broke but the two scenarios are...

    A. Something, but you have covered most bases..
    or
    B. At some point you make the same mistake/don't read or understand the build instructions/ miss a step because you think it isn't needed etc. This ain't doubting you ability, just that we all do this kind of thing at some stage.

    Do you have a local Hackspace or Makerspace where they might be someone to help you?
     
  7. Steven Burns

    Steven Burns Well-Known Member

    Joined:
    Sep 4, 2015
    Messages:
    195
    Likes Received:
    55
    So I have been doing a lot of testing. I thought this might be due to a bad IR Sensor, but if I lower the bed and then raise the bed and place a paper under the sensor before it reaches the top, the bed does stop. So this means the sensor is doing its job.

    The issue appears to be that the printer has set an arbitrary point a Z zero that is 3mm below the nozzle. So my question is; how to I adjust the Z to a different zero point? Not through Z Offset and not through bed leveling. I just need to tell the printer that the Z height that it is registering as zero is wrong.

    I have tried every marlin g code command I can think of, but I am just missing something or having a massive brain fart and overlooking something obvious.
     
  8. Steven Burns

    Steven Burns Well-Known Member

    Joined:
    Sep 4, 2015
    Messages:
    195
    Likes Received:
    55
    I thought I would post an update. I have a working printer!!!!!

    After many back and forth emails with John and Greg at E3D we finally came up with a solution. It appears that the Z Offset was being stored somewhere and quite possibly on the SD card itself. So every time I reloaded the firmware it also reloaded the settings. I cannot confirm this, but the settings were getting stored somewhere.

    They had me download a .hex file with the 1.1 RC6 firmware and a program called Xloader (What a POS that is). I could not get xloader to work at all even from two different PCs so I went a different route to load the hex file via command line.

    Once I had the new firmware loaded and went through commissioning, I am now running my first test print and a ton of calibration will follow (since this is essentially the first print with all new settings).

    Here are the steps I took to load the firmware and balance the hotend PIDs as they had changed as well.

    With Arduino Installed (Replace the paths with your locations):
    C:\Arduino\hardware\tools\avr/bin/avrdude -CC:\Arduino\hardware\tools\avr/etc/avrdude.conf -v -patmega2560 -cwiring -PCOM3 -b115200 -D -Uflash:w:C:\Users\Steve\Downloads\Firmware-master\Firmware-master/marlin_hybrid_pro.hex:i

    BigBox .HEX Firmware
    https://github.com/BigBox3D/Firmware

    PID Calibration (Turn on Verbose Output):
    M303 E0 S200 C8

    Turn off verbose once complete

    Output:
    READ: #define DEFAULT_Kp 15.43
    READ: #define DEFAULT_Ki 0.86
    READ: #define DEFAULT_Kd 69.40

    Enter Command (Writes new PID values):
    M301 P15.43 I0.86 D69.4

    Enter Command (Save Configuration):
    M500

    Thank you so much E3D for taking time to help me with this issue. You're the best!!
     
    Chris Toast likes this.

Share This Page