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X Axis Homing to the right (wrong direction)

Discussion in 'CNC Mills/Routers' started by NewbCNC, Nov 28, 2022.

  1. NewbCNC

    NewbCNC New
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    Hi

    I'm trying to set up a RatRig Killerbee with Blackbox and Interface.

    Using tools and utilities I have turned on homing

    When I run the home function however my Z axis and Y axis perform as expected but the X runs to the right hand side. My limit switch is mounted on the left.

    How do you invert this?
    I've tried switching X direction and axis with the interface > tools & utilities. This switches the jogging directions around (wrong) so I undone that command. I tried switching the cable wires around also on the X axis but this didn't seem to make any difference when I retried the home command.

    Has anybody fixed this issue before and could offer advice?

    Thanks
     
  2. sharmstr

    sharmstr OpenBuilds Team
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    David the swarfer likes this.
  3. NewbCNC

    NewbCNC New
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    That seemed to work.

    I have another question about setting workspace parameters on the opposite side to where the limit switches are.

    My CNC is 1500 x 1000 Ratrig Killerbee

    I came across this in tools and utilities that seem to be presets.

    — Is it possible to set custom presets somewhere so that I avoid collision on the opposite side where no limit switches are found?

    — (soft and hard limits) Do you recommend switching any of these setting on?

    Final comment
    I'm using fusion360 to create the g-code

    — Some presets around workspace in the manufacturing section. Would this be considered good enough or should I add them into the blackbox interface somehow? (I've attached a screenshot)

    Thanks for the help...
     

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  4. sharmstr

    sharmstr OpenBuilds Team
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    Dont use the workbee 1510 config. Its a completely different machine (belts not screws).

    You should learn grbl and about all its settings. Go back to the link I gave you before and look through the wiki.

    You can enable soft limits. To get the true working size of your machine. Home the machine. Set XYZ zero. Jog to each axis extent (how far you want it to travel), use the numbers in the dros to configure your grbl max travel settings.

    BUT before doing all of that, make sure you calibrate your steps per mm.
     
  5. NewbCNC

    NewbCNC New
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    I think I pretty much understand what I need to do but I can't for the life of me see how to do it on the openbuilds interface?

    How input for instance a 100mm travel in one direction to test for calibration?

    I'm looking through tools and utilities can't see anything, checked youtube, no tutorials for the interface, can't see any instructions in the documentation either.

    I have came across an instructional video for openbuilds control. In which case if this is the only way I'd have to download it onto my laptop and plug into the blackbox to get a connection, calibrate and then hope the settings don't change when I work from the openbuilds interface.

    Am I missing something? It would be great to be able to do this from the interface...

    Thanks
     
    #5 NewbCNC, Dec 1, 2022
    Last edited: Dec 1, 2022
  6. sharmstr

    sharmstr OpenBuilds Team
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    Either connect a laptop and use Control or do it the old tried and true way

     
  7. sharmstr

    sharmstr OpenBuilds Team
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    This shouldnt worry you. Settings are saved on the blackbox, not the computer nor the interface.
     
  8. NewbCNC

    NewbCNC New
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    Again, I need to set a distance.

    Lets say I want to move the X axis 100mm to the right.

    Then measure actual distance....

    I can't see anything on the openbuilds interface that allows me to set a distance to travel for testing. Is this possible or is it a case of doing it throught the openbuilds control software instead of the interface?

    Thanks
     
  9. sharmstr

    sharmstr OpenBuilds Team
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    An exact distance doesnt matter. Set 0. Jog to to a spot. Use the dro to see how far the controller thinks it moved. Measure. Do the math for the difference.

    Or, if you really want to move 100mm, then put a gcode file on the usb drive that commands it to move 100mm.

    G1 X100

    But you should really use a longer distance than 100mm. It will be more precise.
     
  10. NewbCNC

    NewbCNC New
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    I got my laptop and used the openbuilds control software. It was pretty easy with that and worked great.
     
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  11. sharmstr

    sharmstr OpenBuilds Team
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    That's great.

    I was thinking about this statement...

    You need Control to properly deploy an Interface. So are you sure you went through all the steps in the Interface doc? Maybe I'm misinterpreting what you have said, but it seems like you were implying that you've never used Control.
     
    Peter Van Der Walt likes this.
  12. David the swarfer

    David the swarfer OpenBuilds Team
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    just write a little Gcode
    Code:
    G21 G90 G54 G17   ; always set the modes you wnat and need
    G0 X100                   ; move X from 0 to 100
    M30                         ; end program
    
     
  13. David the swarfer

    David the swarfer OpenBuilds Team
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    don't forget to review the resource on calibration
    HOWTO Calibrate your CNC Machine for MACH3 or GRBL
    but using the OBCONTROL calibration wizard is much the easiest thing to do, even with having to install it and carry the laptop to the workshop (-:
     
  14. NewbCNC

    NewbCNC New
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    So, I've now calibrated and set soft limits which works great. Thanks for all the help...

    Firstly, I did all this by plugin my laptop into the blackbox controller and running openbuilds control. The long term solution is to use the blackbox interface once all set up.

    So, when I plug in the blackbox interface and home then reset 0 points I can move to all my softlimits... (all good)
    softlimts x745 z85 y1200

    the problem comes when I switch the power off. I think my home settings are wrong. I'd ideally like them to register as 0,0,0

    If you look at the image this is what is showing. It basically means I can't move right on the x axis without it hitting its limit after 2mm or so.

    I can work around it by turning off the softlimit, resetting the 0 and then turning them back on. However, this seems like a bit hacky. I'd like to reset the homing so when it registers at the limit switches that is considered 0,0,0 when I turn the system on and off.....

    Hopefully this makes sense?

    Aside from when this is sorted I think I'm pretty much ready to start working on the spoil board.
     

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  15. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    Have a read through Frequently Asked Questions · gnea/grbl Wiki first

    Soft Limits needs Homing. And Soft Limits works great when Homing is set up correctly
    - Make machine JOG correctly first ($3 Direction Invert)
    - Tell machine WHERE the switches are ($23)
    - Configure MAX TRAVEL correctly (Soft limits enabled = CONTROL and Interface takes current Machine Position and Subtracts it from Max Travel to know how far to send jog command. If not setup correctly this math is wrong)

    Remember HOMING sets MACHINE COORDINATES.
    You, the operator - sets WORK COORDINATES by Zeroing or Probing - and that's what shows in the DRO
     
  16. NewbCNC

    NewbCNC New
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    Hi Peter, yes I've read the link provided. It, doesn't answer my question on how to amend my home co-ordinates so that they are established as the 0,0,0 as far as I can work out?

    It mentions co-ordinates being in the negative. Not sure if that is causing the issue? My soft limits work so its a little confusing to me as a beginner. I'm assuming theres a very simple operation I can do to register my limit switches as 0,0,0 if that is indeed the right solution to ensure I don't have the issue on the X axis if I turn the CNC off.

    — I've inverted the direction on the X axis for homing (so now it moves to the negative) correct....
    — As far as I can tell the machine knows where the switches are because it does home to them (this might be where the issue is though)
    — I set up max travel limits, the soft limits work as I would like. (issue comes when I turn off the machine as mentioned and use the blackbox interface)
     
  17. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    It does. It basically says it shouldn't :)

    Homing tells the controller "where is the machine" in the real world. 0,0,0 is ALWAYS on the far right, far back, all the way up (on a gantry machine) because thats where it SHOULD be so the entire machine lies in the negative quadrant that most CAMs expect. If your switches are on the front/left that point is -maxX, -maxY (negative max travel - so that positive moves moves it toward 0,0)

    Interface can't show Machine Coordinates - you are seeing Work Coordinates.

    So confirm: Jogging X+ moves the Endmill towards the Right?
    Homing X moves the carriage LEFT, and the switch is on the LEFT (As shown in our videos)

    Correct, but if $3 and $23 are both incorrect, it will still home toward the switch - but be incorrect. Thus important to check Jog directions first.


    Do you remember to HOME before jogging? After power off - you need to HOME so the controller knows where the physical machine is again
     

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