Some other little hints for starting...



  • Good morning, the moment I'll mount my Duet WiFi to my custom CoreXY is getting really closer! As I told in my previous posts I come from the Marlin world (well, to be honest from a Marin's fork) so for me it's now all a little hard to understand how RFF works so I know I'll have to face a lot of studying to understand it well. For now I need some basic infos to make my printer to start moving....first: the printer is based on a TronXY X5S chassis but the X gantry as well as the extruder plate has been totaly changed from the original ones so the first thing I need to know is how adjust the X and Y offsets for the nozzle to make it to be placed in the right coordinates of the plate. I try to explain better: my plate is 330x330 mm and I want that if I send the nozzle G1 X165 Y165 the nozzle will be placed exactly in the middle of the plate. Marlin has a feature to do so, how can I make this adjustment in RFF?
    Second question is about the Z offset. I'll use an orginal BLTouch V3.1 as Z probe but I can't find how to calculate and "store" the Z offset value....to calculate the Z offset in Marlin i did the following steps:

    1. M851 Z-4
    2. G28 Z0
    3. Slowly lower the Z until the nozzle starts to scratch a piece of paper placed between the nozzle itself and the plate
    4. The new Z offset will be the actual reading of the Z minus 4 plus 0,01 for the paper thickness
      After that M851 Z new_value and M500 to store it in EEPROM

    except for the M500 is this a correct procedure even for RFF? In case it's not how can I calculate and store the Z offset?

    Least but not last a question: is it possible to have the X and Y homing in the front left corner of the plate and the Z homing in the center of the plate?

    Thanks and sorry for the long post (and for the bad English as well)
    Andrea



  • You can adjust the M208 minima to account for axis overhang.
    E.g. if when you home the X axis, the nozzle is only on the build plate when you get to 10, set the minima to -10. Then when it homes, the home position is -10 and not 0.

    For the z probe, read this https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe



  • @jay_s_uk said in Some other little hints for starting...:

    You can adjust the M208 minima to account for axis overhang.
    E.g. if when you home the X axis, the nozzle is only on the build plate when you get to 10, set the minima to -10. Then when it homes, the home position is -10 and not 0.

    For the z probe, read this https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe

    Thanks! For the M208 i can use the method to track two diagonals in the plate (using paper tape) and the send the nozzle G1 X165 Y165 and measure the difference and store them in config.g with the M208?



  • If you know you bed is 330mm wide, it would be easier to home your nozzle and then jog it until you're over the edge of the bed. The amount you've jogged is then your negative offset.



  • Hi,

    With the Duet firmware M500 doesn't write to EEPROM, it creates a file called config-override.g which has certain commands in it - some are related to calibrating a delta printer - some are related to tuning heaters.

    In any case to use that file you put a M501 at the END of your config.g file

    Instead of using M501 you can move the contents of config-override.g into the appropriate place(s) in your config.g if you want to keep things together.

    Frederick



  • Hi again,

    As to the Z offset value:

    What you are already doing will get you the correct value (or very close to it).

    To save it you edit your G31 command, where ever it is, often in your config.g file.

    The Z parameter below is what you edit, the other parameters are unique to your particular Z probe. The other values you see below are for my BLTouch, they likely won't apply to your printer.

    G21 P25 X0 Y24.5 Z2.470

    Frederick



  • @the_dragonlord said in Some other little hints for starting...:

    I need to know is how adjust the X and Y offsets for the nozzle to make it to be placed in the right coordinates of the plate. I try to explain better: my plate is 330x330 mm and I want that if I send the nozzle G1 X165 Y165 the nozzle will be placed exactly in the middle of the plate.

    I'm not sure I fully understand your question.

    There is a command to set the X and Y offsets for the nozzle but they are not used for that purpose.

    That command is used when you have a printer that has two nozzles and you need to tell the firmware how they are physically positioned, relative to one another.

    If the goal is simply to have G1 X165 Y165 move the nozzle to the center of the bed then I need to know what the command is doing now instead.

    Thanks.

    Frederick


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