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Machine tries to start from home and not starting coords

Discussion in 'OpenBuilds Forum Help' started by Calgarus, Aug 20, 2022.

  1. Calgarus

    Calgarus New
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    Hello,


    I'm using Fusion 360 and I've set my WCS to the bottom left corner of my stock (Z+up, Y=back, X=right).

    I've been using the XYZ probe to zero out my machine. The weird part is I had it working great but now it's plunging at the corner of my stock instead of moving to where it should actually be starting.

    I am just getting started and cant seem to figure out what setting I could of changed to make it start at home and not where it used to.

    Any help would be appreciated.


    Thanks.
     
  2. Alex Chambers

    Alex Chambers Master
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    If this is a grbl machine are you;

    A) using the openbuilds post processor for Fusion (docs:software:fusion360 [OpenBuilds Documentation]

    B) Homing your machine before setting the wcs?

    C) are you setting your wcs Z zero (and the origin in Fusion) to the workpiece surface or the spoilboard?

    Alex.
     
  3. Calgarus

    Calgarus New
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    I'm using the F360 post processor and the Blackbox.

    I am currently just turning it on and moving it to the probe location and running the probe command.

    The WCS is set in fusion, no? Other than selecting the top corner of the stock, I just have it set to 1 which is G54 I think.

    I am setting the point to the top of the stock which is flush with the top of the actual material.

    I just manually set the zero on the machine, without using the probe and it moved the the first pocket like before and started cutting...

    Not sure where that leaves me other than knowing it has something to do with the probe? Lol
     
  4. Alex Chambers

    Alex Chambers Master
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    The Openbuilds post processor for Fusion relies on the machine home position being set as it uses machine co-ordinates (G53) for the first safety move.
    You tell Fusion in the cam setup which wcs you are going to use and you set an origin (eg front, left, top corner of stock) to use as a reference point. You set the wcs zero (in the same place on your workpiece as you set the origin in your cam) on your machine.
    Grbl sets the MACHINE co-ordinate system zero (home) wherever the machine is when you switch on unless you run the homing command (do you have homing/limit switches?). The wcs zero is stored as an offset from the machine co-ordinates system zero, so unless you home your machine there is no fixed reference point that Fusion can work from.
    Alex.
     
    Peter Van Der Walt likes this.
  5. Calgarus

    Calgarus New
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    I don't have limit switches.

    So for the probe to work properly again, I have to set a random home and then use the probe?

    I'm still trying to figure out how I got it to work perfectly several times before and now it's not haha.

    I appreciate your help.
     
  6. Alex Chambers

    Alex Chambers Master
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    Try having a read of this resource by @David the swarfer.

    How to 'Fake the home'

    Alex.
     
    Peter Van Der Walt likes this.
  7. David the swarfer

    David the swarfer OpenBuilds Team
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    Peter Van Der Walt likes this.
  8. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    Or just get the Switches and install it. Couple bucks, 10 mins of your time for a lifetime of repeatable and predictable offsets, proper Machine Coordinate moves, and ease of use
     

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