Z Min zero and reading Zmax value

  • Hi all, I'm new to the Duet wifi and RepRap firmware, just trying to figure out what to do, as the documentation is a bit "all over the places" and a little confusing from someone coming from Smoothieware…
    There's any chance I can set the nozzle at Zero(min distance like G92 Z0) and then give the G28 Z command to know automatically which the Zmax height is in mm?
    I have my CoreXY with the Zmax endstop working as the G 28 command is issued and the bed goes lower and far from the nozzle.
    If someone could tell me what to do exactly in the config.g or bed.g and not just tell me to look at the RepRap wiki page that would be wonderful!!
    Thank you for any help

  • administrators

    Yes, you can if you are running recent firmware. Position the nozzle so it is touching the bed. Send G92 Z0. Then send G1 S3 Zaaa Fbbb where aaa is larger than the length of your Z axis and bbb the speed at which you normally home the Z axis. It will stop when it triggers the endstop switch, Then run M208 and read off the Z value. Copy that value into the M208 S0 command in config.g.

    Please share your thoughts on how we can better organise the documentation. We are in the process of migrating it to a new system (Dozuki).

  • Hi dc42,
    First of everything thank you a lot for the answer!!
    I was near to put the board in a corner and roll back to smoothieboard…

    My thought about how to organize the documentation is very simple:

    First of all, the technical documentation about the board, including pin assignment and control, expansion board and daughter boards (PT100 etc) has to be documented with pictures and pin number assignment and how to control each of them (if not already done)

    I would start to organize and divide the docs into sections for each frame( Delta, CoreXY, Cartesian, etc)
    Many commands in the documentation are referring to a delta setup, but then indicated and assumed as good as for other frames, which is correct as they basically are always the same, but as the RepRap firmware has a lot of commands and variables(options), that could be confusing for a novice (like me for example).

    Second, (I know can be boring) I would create various sub-sections for each frame (XY Axis setup and enstops management(fully documented including stall detection management), then Zaxis setup and Z height calibration with clear examples, bed leveling, and bed compensation(mesh) and examples to "how to" with sections of Config.g and Bed.g files clearly explained and so on, then last but not less important, temperature tuning and the cooling fans with the long list of examples all collected together and VERY well explained.

    It would be very important to just click on the page of the frame (and sub-menu) of the part you need the setup or help for.
    Counting on pictures and detailed drawings would be helpful always...

    At today, for example, I am still calibrating the nozzle, as the temperature is not stable, and with the same hardware setup as it was on the smoothieboard, i have to increase the temperature about 30 degrees to print the same material...

    I am sure Duet is a great board, but if not clearly and fully explained it cannot be enjoyed properly at 100% and would be a shame.

    I don't know if what I said make any sense, and maybe is not clear as my English is very bad (I apologize for that), and anything I said shouldn't be interpreted as a criticism, but just as a constructive suggestion.
    I am obviously more than happy to help if I can.

    Best regards

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