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CNC Router cuts a mirror mage

Discussion in 'CNC Mills/Routers' started by F Kaylor, Jul 27, 2018.

  1. F Kaylor

    F Kaylor New
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    I'm using Vectric Cut2d and ugs to run my machine. But it cuts a mirror image of what I've drawn in Cut2d. On the UGS screen, the drawing is correct (meaning the bottom of the drawing is on the bottom) but the machine cuts it in reverse...producing a mirror image. My machine is square and calibrated, homing moves in the correct direction...everything seems spot on...except for this... I don't have a clue what is going on but it wouldn't surprise me if the culprit is me! Can someone shed a bit of light, please. Thanks
     
  2. Giarc

    Giarc OpenBuilds Team
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    I assume you have this correct since you calibrated, but just to eliminate something for certain, when you type G0 x100 in UGS and send the command does it go the proper direction (ie direction you expect)? same with G0 Y100?

    I am not familiar with vectric, but is there potentially a box that you check that tells it to cut a mirror image?
     
  3. F Kaylor

    F Kaylor New
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    Thanks Craig...yes all axes go in the correct direction. What confuses me is that the image drawn in Vectric and displayed in UGS are the same but the cut is a mirror image. Not really a problem when cutting symmetrical projects but in the current project it is not symmetrical and therefore not usable. I'll dig through Vectric and make sure there are no mirror image check boxes...don't think there are but it's worth a check. Thanks for responding.
     
  4. F Kaylor

    F Kaylor New
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    I THINK I may have found the problem. I got my old CNC out of mothballs and ran the same project on it and guess what...no mirror image. So the issue must be in the machine, not in the CAD/CAM software. Reviewing the settings on the machine in question, the current setting for $3 is 6, inverts Y and Z but not X. I THINK I need to change from $3=6 to $3=11 (invert Y,Z,and X) and change the coil on the X Stepper...theory right now but I'm going to give that a try!...
     
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  5. F Kaylor

    F Kaylor New
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    Update: "All that glitters is not Gold" Thought I had a solution but was wrong. In the previous post I referenced "$3=11"...should have been $3=7". As it turns out that wasn't the solution. So then I I took out all of the invert $3=0, checked the direction of each stepper and changed coils as needed and expected the mirror image problem to be solved...not so...now back to square one...still dazed and confused!
     
  6. JustinTime

    JustinTime Veteran
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    Is the object mirrored along the x axis or the y axis? What ever axis that it is mirrored along is the axis that has to be reversed.
     
  7. F Kaylor

    F Kaylor New
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    Yes, the issue is along the Y axis so I inverted the Y axis ($3=2) and then reversed the Y axis stepper (and slave) by reversing one of the coil leads for each of the 2 Y axis steppers. Unfortunately, this made no difference...the mirror mage is still there. In thinking about it, wouldn't reversing the G Code ($3) then the stepper coils just cancel out reversing in G-Code?
    For clarification, my machine uses homing switches and homes in the back left side when facing the machine. So X moves to the right and Y brings the gantry forward...nothing out of the ordinary with that set up is there?
     
  8. Gary Caruso

    Gary Caruso OpenBuilds Volunteer
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    FK,
    Yes what you did was like a double negative.. canceled out.. you need to reverse the Y using $3 and then reverse your home direction for Y using $23
    same chart as the $3 sets up your home direction.
    Cheers
    Gary
    upload_2018-7-29_16-48-45.png
     
  9. F Kaylor

    F Kaylor New
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    Thanks Gary...so I don't get confused, I should undo the "Double Negative"...either $3 or swap coil leads, then reverse Y at $23? per the chart?
    FK
     
  10. Gary Caruso

    Gary Caruso OpenBuilds Volunteer
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    Right, get the Y moving in the correct direction and use $23 to get it moving in the correct direction for your homing position.
    Using $3 is easier than swapping coils.
     
  11. F Kaylor

    F Kaylor New
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    Since I'm not sure what I'm doing here and my efforts to reverse Y in $23, I set $3=0, then changed coils so that all steppers moved in the correct direction, including home. Below are the current GRBL settings...perhaps that will shed some light...
    $0=10

    $1=255

    $2=0

    $3=0

    $4=1

    $5=0

    $6=0

    $10=1

    $11=0.020

    $12=0.002

    $13=1

    $20=1

    $21=0

    $22=1

    $23=3

    $24=500.000

    $25=2500.000

    $26=250

    $27=5.000

    $30=1000

    $31=0

    $32=0

    $100=395.061

    $101=395.273

    $102=397.351

    $110=2500.000

    $111=2500.000

    $112=2500.000

    $120=50.000

    $121=50.000

    $122=50.000

    $130=500.000

    $131=550.000

    $132=140.000

    Thanks for all of your help!
    FK
     
  12. Gary Caruso

    Gary Caruso OpenBuilds Volunteer
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    Hi FK,
    You don't need to swap coils to change direction, when you can use $3 to do this..
    When you home in the back left that is where you are having the issue, back left would be max Y and Min X.
    When you Jog does the down arrow on your screen move the gantry toward you or away?
    I would think $3=2 and $23=5 would fix your issue.. don't swap any coils

    Also are you using 3200 steps per turn, most people are running 1600 or 1/8 micro on screws, i think 1/200th of a mm is good enough ;)
    And it will get you a little more torque and higher speed possible when moving.
    You can turn you acceleration way up from where you are, try $120, 121, 122 =500 and see how much faster you get up to speed.
    good luck
    Gary
     
  13. F Kaylor

    F Kaylor New
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    Thanks Gary! Changing the homing to the front left will require relocating the Y homing switch...which I can do. My old machine homed in the back left and it seemed logical to me so I set the new one up the same...but I'll make the changes. Also, thanks for the advice on the other settings...I'll make those changes as well. Will report the anticipated success but it will be tomorrow before I can get back in the shop...wedding anniversary today!

    Noticed your Avitar...are you an RC enthusiast? That's my passion and what ultimately led to CNC...
    FK
     
  14. Gary Caruso

    Gary Caruso OpenBuilds Volunteer
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    FK yes, bug time RC nut, cnc has been taking all my time though... this winter hope to start cutting some kits.
    You can leave the home anywhere you want just make those two setting changes..
    Cheers
    Gary
     
  15. F Kaylor

    F Kaylor New
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    Gary: Made the stepper and acceleration settings as suggested...still need to recalibrate but I can do that...sounds and acts like a new machine!

    Changed $3 to 2 but when I changed $23 to 5, Z was backwards, so I changed $23 to 1. Now the Y gantry moves in the opposite direction...a y- jog moves the gantry to the front...not the rear as before. But the good news is that the mirror image is gone. The question is...should I just live with the "Backwards Y", move home to the front left...or what? Regardless...progress has been made....THANKS!
    FK
     
  16. Gary Caruso

    Gary Caruso OpenBuilds Volunteer
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    $23 is the home direction.. if 1 works then fine.Something isn't right still
     
  17. F Kaylor

    F Kaylor New
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    Gary: Should I change the Y home switch to the front left and $23 accordingly? It's difficult to troubleshoot obscure issues like this, but I do appreciate your help!
    Thanks
    FK
     
  18. David the swarfer

    David the swarfer OpenBuilds Team
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    GRBL defaults to the industry standard of having home at the positive ends of travel.
    Positive and negative directions refer to TOOL movement relative to the part!
    So on an OX we have
    X+ is tool to the right
    Y+ is tool further away form the operator
    Z+ is tool UP away from the bed.

    and that is where the home switches should go.

    and please don't moan about negative space! you just jog to where the part 0,0,0 is and set 0 there (all the GUI's have a button for this) and bingo everything on the part is positive (just as it would be if you homed anywhere else). *you* don't need to do any thinking about negative numbers, GRBL does it for you.
     
  19. F Kaylor

    F Kaylor New
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    David: Thanks for the reply. If I understand you correctly, the X Limit should be at X Max which is all the way to the right; the Y limit should be at Y Max which is all the way back...away from the operator... and of course Z Is Up. Currently the only limit that is not in the correct location is the X limit which is all the way to the left. I think this may have been mentioned previously, but didn't register with me...and along with relocation of the X limit is the associated changes in $23 so that all axis move in the correct direction during homing cycle.

    Not sure what you meant about moaning over negative space...the only thing I'm moaning about is how little I know about this and how much I need (and am eager) to learn...Thanks again for your help.
    FK
     
  20. F Kaylor

    F Kaylor New
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    David and Craig: I relocated the X limit switch to the right (X max), set $23 to 0, Y Limit switch was and is at the back and Z was and is at the top. Ran a test cut and no more mirror image...problem solved. My next step is to recalibrate the steps/mm and confirm X and Y are square...I've done that several times previously so that should be easy.
    Thanks again for all of your help!
     
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  21. F Kaylor

    F Kaylor New
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    Another comment...
    The problem I WAS having is the reason why it is a bad idea to buy a CNC Router knock off from China...unless you are a seasoned professional you should get your system from a source that supports and helps with real information. I read as much as I could find and watched all of the videos and it became very clear that OpenBuilds provided the quality parts and support to build a system and when you run aground as I did...there is help...Thanks again for the help!
    FK
     
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  22. David the swarfer

    David the swarfer OpenBuilds Team
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    I recommend turning off all the homing stuff and get the motion directions correct first.
    Once that is working enable homing and get that working.
     
  23. David the swarfer

    David the swarfer OpenBuilds Team
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    hehe, my bad, just about everyone complains that the standard homing position puts the working area into negative numbers. Thing is that it really just does not matter because you can just jog to where you need the tool to be and then set work zero there, no need to even look at the absolute numbers.
     
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  24. David the swarfer

    David the swarfer OpenBuilds Team
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    'How to calibrate resource' here on openbuilds HOWTO Calibrate your CNC Machine for MACH3 or GRBL
     
  25. F Kaylor

    F Kaylor New
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    Thanks David. I had seen the calibration resource on OB and that's the method I use...works and is quite easy...
    FK
     
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