Tool offsets and finding (0,0) + G10, G31...

Discussion in 'Tool heads & ToolChanger' started by Joe Pomo, Jun 11, 2020.

  1. Joe Pomo

    Joe Pomo Well-Known Member

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    I have two questions:

    1). Regarding G10... Step 2 in this section has us find the XY offsets for each tool:
    https://e3d-online.dozuki.com/Guide/12+-+Multi-Material+Calibration./114?lang=en

    The original G10 line is: "G10 Pn X-9 Y39 Z-5"

    Are these XY "starting points" in relation to the tip of the Omron switch?

    2). G31 in the config.g reads "G31 P200 X0 Y0 Z0"

    Should I be using the X & Y parameters to declare an offset of the Omron switch in relation to my T0?


    I appreciate any help!
     
  2. Michael Pearson

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    You are tuning the X Y offsets of T1 T2 and T3 in relation to T0. So you print the tool calibration print and use that to adjust the numbers in the G10 command for T1-T3 so it matches T0.
     
  3. Joe Pomo

    Joe Pomo Well-Known Member

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    Thanks for the feedback. Tuning the offsets in relation to T0 makes sense.

    However, if T0 is supposed to be our reference, then I would assume that it's position would be (0,0), and all other offsets would be tuned in relation to that. But in reality, G10 already has an offset with respect to some other datum because for T0 the command reads "G10 P0 X-9 Y39". So I wonder if the datum is the Z-probe (Omron switch?)

    Thanks!
     
  4. Andy Cohen

    Andy Cohen Well-Known Member

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    T0 is still offset. The nozzle tip is not at the spot that the OMRON switch sets as 0 for Z. If T0 is too close or too far you first have to correct the offset for T0 before you know the other 3 will be correct. To do that I always use the G10 commands at the end of the config file. BTW I always have the following as a remark by these commands: "Positive moves closer, negative away"... from the bed that is.
     
  5. Joe Pomo

    Joe Pomo Well-Known Member

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    Thanks Andy. I found some information in the Jubilee printer docs:
    https://jubilee3d.com/index.php?title=Setting_Tool_Offsets

    My understanding of this is that the Z-probe (Omron switch) is considered close to 0,0 (but probably not exact) and the default (E3D-supplied) G10 values are in reference to this. And then every tool is referenced from T0 thereafter.

    The whole reason I looked into this is because I have only 2 hemeras + a spindle tool on my machine. I think the default G10 values were made by E3D in reference to a V6 tool, so I think I need to adjust the original values to reference my T0 which is a hemera, and has different mount/offset.

    Thanks!
     
  6. Andy Cohen

    Andy Cohen Well-Known Member

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    That is correct. The instructions assume all four tools have a V6.
    If you have different extruders you cannot simply adjust in relation to T0. In that case you will need to set the offset in Z per tool and not use the offset method the TC instructions refer to(printing out the pattern). Also... the G10 commands set the offsets. There's nothing that automatically relates the other tools to T0. The method E3D uses in the instructions to set the offsets are relative to T0 for how you calculate how much to change the offset (it's way overcomplicated in my opinion).

    BTW... What is a "spindle tool"?
     
    #6 Andy Cohen, Jun 13, 2020
    Last edited: Jun 13, 2020
  7. Joe Pomo

    Joe Pomo Well-Known Member

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    Thanks for confirming, Andy, I appreciate it.
    I've been experimenting with using a spindle tool that holds an 1/8" endmill or similar cutter.

    I had success using a dremel flex-shaft and I just built a new tool using a BLDC motor from an RC plane or drone. (Images attached)

    I have no idea if the BLDC one will work, but I'll report back in this thread:
    https://forum.e3d-online.com/threads/anyone-doing-subtractive.3769/#post-36978.

    I was inspired by this article:
    https://hackaday.com/2014/08/03/brushless-dc-motor-used-for-high-speed-cnc-spindle/
     

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