Problem Z needs to be negative to cut from zero which is top of part. How to configure?


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Thread: Z needs to be negative to cut from zero which is top of part. How to configure?

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    Default Z needs to be negative to cut from zero which is top of part. How to configure?

    My machine is setup so that when the tool is zeroed on top of the part gcode Z instructions must be negative to cut and positive to rapid. I have been using Vectric VCarve Pro for 5 years with no issues or problems. I am trying MadCam because of some 3D issues with VCarve. I am using Rhino 5 for design. When I calculate a tool path with MadCam the numbers are always positive. What I need and what VCarve does is set Z rapid to positive and Z cuts to negative values. I cannot figure out how to setup MadCam to do this. I am using 3Axis curve milling "From Boundary Curves". I thought I might get the right numbers by moving the boundary curve to the top of the part but it made no difference. I have tried -1 in ZScale in the post processor to no avail as everything is then negative in the gcode. I am at a loss and a turning point. I'm too vested in the machine to change the direction of the Z-Axis in Mach3 and/or the servo driver. Everything would be affected by that, the ATC and all previous Gcode files. I would really like to see MadCam work for me but may have to let it go if no solution exists and then I'm back to square one. I hope this is just a dumb newbie user problem I will happily take the dumb user title. Thanks in advance.

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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Quote Originally Posted by aperio View Post
    My machine is setup so that when the tool is zeroed on top of the part gcode Z instructions must be negative to cut and positive to rapid. I have been using Vectric VCarve Pro for 5 years with no issues or problems. I am trying MadCam because of some 3D issues with VCarve. I am using Rhino 5 for design. When I calculate a tool path with MadCam the numbers are always positive. What I need and what VCarve does is set Z rapid to positive and Z cuts to negative values. I cannot figure out how to setup MadCam to do this. I am using 3Axis curve milling "From Boundary Curves". I thought I might get the right numbers by moving the boundary curve to the top of the part but it made no difference. I have tried -1 in ZScale in the post processor to no avail as everything is then negative in the gcode. I am at a loss and a turning point. I'm too vested in the machine to change the direction of the Z-Axis in Mach3 and/or the servo driver. Everything would be affected by that, the ATC and all previous Gcode files. I would really like to see MadCam work for me but may have to let it go if no solution exists and then I'm back to square one. I hope this is just a dumb newbie user problem I will happily take the dumb user title. Thanks in advance.
    Not really sure what your problem is then, If the software is working correct then, every Z axes move from your tool Zero ( Top of Part ) has to be negative

    This is how it should be working if it is not, then, you either have your machine setup incorrect, or you are not using your software correctly, when setting up your part and tools

    Positive is Z axes up no matter whether it is a Feed move or a Rapid move

    Negative is Z- axes moving down whether a Feed move or a Rapid Move

    Mactec54


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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Thanks MacTec54. I agree with you. I do not believe MadCam is working correctly. But I don't know how to solve it. I have the latest version 5 release of Madcam. The machine is cutting properly with recent files generated from Vectric. Those files have negative numbers for z axis moves when cutting and positive numbers above zero. All gcode files created from Madcam in Rhino have positive numbers for ALL z axis moves. I have attached a snapshot of a file I just created from MadCam. and an existing file from Vectric. Clearly the peoplem is the unsigned numbers in the Madcam file. I may be over looking the obvious but cannot find how to correct this in MadCam.
    Z needs to be negative to cut from zero which is top of part. How to configure?-madcam-sample-jpg Z needs to be negative to cut from zero which is top of part. How to configure?-vectric-sample-jpg



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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    aperio,
    I you Job in set Below the Zero Plane in Rhino then All Z Cuts will end up being MINUS Z and if the Job is Above the Zero Plane in Rhino then All Z Cuts will end up being PLUS Z.
    Regards,
    Mauri.



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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Like Mauri says, move your zero point to origo in Rhino (or wherever you want it in your machine). The Rhino workspace represents your machine's workspace.



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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Quote Originally Posted by svenakela View Post
    Like Mauri says, move your zero point to origo in Rhino (or wherever you want it in your machine). The Rhino workspace represents your machine's workspace.
    A little background. I have always made my parts with an origin of 0,0,0 in the lower left corner In Rhino. So the part is built on top of the construction plane with z=0 at the bottom of the lower left hand corner. When these parts are exported in STL format and then brought in to Vectric the Work Zero is defined in Vectric at the top of the part and it all works well.

    In trying to follow your advice for MadCam on moving the Z-zero point in Rhino I moved the elevation of the CPlane to the top of the part, regenerated the surface region and tried to generate a tool path with MadCam and I still get the same positive numbers in the GCode file. If I display the Box-Region dialog it contains X-Top=1.018 and X-Bottom = 0.2499 which is my part region. Am I not defining the Z-Zero properly? I don't know how else to do it but I am always learning about Rhino.

    My impression with Madcam is the Box Region defines the Work Zero surface using Z-Top and Z-Bottom. I feel I must be wrong about this though. If I set X-Top to 0 and X-Bottom to either 1 or -1 MadCam fails to generate a path.

    I have attached pictures of my work piece with the tool path and the box-region. Z-Top is 1.0018 and the Z-Bottom is 0.2499. The first picture is with the CPlane at the top of the part. It is difficult to discern. The second picture is with the CPlane moved to the bottom of the part and the corresponding GCode generated from MadCam. There is no difference. You can see that the Box Region still contains the same values for both Z-Top and Z-Bottom so they are always relative to the CPlane not absolute.

    As an aside and others have reported this, the settings for the tool table never maintain themselves. I use inches and selected that in the settings dialog but every time I click on the tool button on the toolbar it is showing millimeters. I don't think this is connected to my immediate problem but thought it might be worth mentioning.

    I am really stuck here and know that MadCam should do these parts fairly easily and it may be something simple I am missing but I am at a loss. I do appreciate all the help so far. Also if there is a better way to include images let me know. I can use drop box but am concerned about potential attacks via the link.

    Z needs to be negative to cut from zero which is top of part. How to configure?-box-region-polysurface-toolpath-cplane-top-jpg Z needs to be negative to cut from zero which is top of part. How to configure?-gcode-box-region-polysurface-toolpath-cplane-top Z needs to be negative to cut from zero which is top of part. How to configure?-box-region-polysurface-toolpath-cplane-bottom-jpg Z needs to be negative to cut from zero which is top of part. How to configure?-gcode-box-region-polysurface-toolpath-cplane-bottom



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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Quote Originally Posted by aperio View Post
    A little background. I have always made my parts with an origin of 0,0,0 in the lower left corner In Rhino. So the part is built on top of the construction plane with z=0 at the bottom of the lower left hand corner. When these parts are exported in STL format and then brought in to Vectric the Work Zero is defined in Vectric at the top of the part and it all works well.

    In trying to follow your advice for MadCam on moving the Z-zero point in Rhino I moved the elevation of the CPlane to the top of the part, regenerated the surface region and tried to generate a tool path with MadCam and I still get the same positive numbers in the GCode file. If I display the Box-Region dialog it contains X-Top=1.018 and X-Bottom = 0.2499 which is my part region. Am I not defining the Z-Zero properly? I don't know how else to do it but I am always learning about Rhino.

    My impression with Madcam is the Box Region defines the Work Zero surface using Z-Top and Z-Bottom. I feel I must be wrong about this though. If I set X-Top to 0 and X-Bottom to either 1 or -1 MadCam fails to generate a path.

    I have attached pictures of my work piece with the tool path and the box-region. Z-Top is 1.0018 and the Z-Bottom is 0.2499. The first picture is with the CPlane at the top of the part. It is difficult to discern. The second picture is with the CPlane moved to the bottom of the part and the corresponding GCode generated from MadCam. There is no difference. You can see that the Box Region still contains the same values for both Z-Top and Z-Bottom so they are always relative to the CPlane not absolute.

    As an aside and others have reported this, the settings for the tool table never maintain themselves. I use inches and selected that in the settings dialog but every time I click on the tool button on the toolbar it is showing millimeters. I don't think this is connected to my immediate problem but thought it might be worth mentioning.

    I am really stuck here and know that MadCam should do these parts fairly easily and it may be something simple I am missing but I am at a loss. I do appreciate all the help so far. Also if there is a better way to include images let me know. I can use drop box but am concerned about potential attacks via the link.

    Z needs to be negative to cut from zero which is top of part. How to configure?-box-region-polysurface-toolpath-cplane-top-jpg Z needs to be negative to cut from zero which is top of part. How to configure?-gcode-box-region-polysurface-toolpath-cplane-top Z needs to be negative to cut from zero which is top of part. How to configure?-box-region-polysurface-toolpath-cplane-bottom-jpg Z needs to be negative to cut from zero which is top of part. How to configure?-gcode-box-region-polysurface-toolpath-cplane-bottom
    You are correct with the way you are thinking this should work in the cam program, that is the normal way to change any X Y and Z axes positions

    Mactec54


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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Quote Originally Posted by mactec54 View Post
    You are correct with the way you are thinking this should work in the cam program, that is the normal way to change any X Y and Z axes positions
    Thanks Mactec54. It helps to know that I am at least in the ball park. Now if I could just get to first base!



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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Quote Originally Posted by aperio View Post
    Thanks Mactec54. It helps to know that I am at least in the ball park. Now if I could just get to first base!
    Anyone else have any ideas? I'm really stuck on this. Perhaps I need to take it over to Madcam support? I hate to do that if someone knows what the problem may be. Thanks in advance.



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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Move your model below zero (Origo), select the objects you want to cut and click the first icon in the Madcam toolbar. Then go ahead and make your toolpaths. The workbox you only need to modify when you want to change the default restriction of the machine movement.

    The attached toolpath generates negative numbers:


    Z needs to be negative to cut from zero which is top of part. How to configure?-minus1-jpgZ needs to be negative to cut from zero which is top of part. How to configure?-minus2-png

    Attached Thumbnails Attached Thumbnails Z needs to be negative to cut from zero which is top of part. How to configure?-minus1-jpg   Z needs to be negative to cut from zero which is top of part. How to configure?-minus2-png  


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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Thank you Svenakela. In fact as you wrote your reply I was doing just what you suggested and it is working though I have not run the file yet but will in about 10 min.

    My mistake is that I was moving the construction 'CPlane elevation' expecting it to change the Z Origin. When in fact it does not. I then played with Setpt with combinations of CPlane. I believe there must be a way to change the Z orgin with CPlane and another command but I do not know what it is and I am not a Rhino guru. I was hesitant to move the model as it is quite complex and things left alone are sometimes better left that way but in the end did exactly that.

    If I could make a suggestion to Madcam it would be to follow along the lines of Vectric and RhinoCam in setting the work zero. It would be much more intuitive and most importantly does not require moving the model below the construction plane which I believe for most people is at 0,0,0 and things are built on top of it. That's my two cents worth.

    Thank you again for looking into this problem for me.



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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Quote Originally Posted by aperio View Post
    Thank you Svenakela. In fact as you wrote your reply I was doing just what you suggested and it is working though I have not run the file yet but will in about 10 min.

    My mistake is that I was moving the construction 'CPlane elevation' expecting it to change the Z Origin. When in fact it does not. I then played with Setpt with combinations of CPlane. I believe there must be a way to change the Z orgin with CPlane and another command but I do not know what it is and I am not a Rhino guru. I was hesitant to move the model as it is quite complex and things left alone are sometimes better left that way but in the end did exactly that.

    If I could make a suggestion to Madcam it would be to follow along the lines of Vectric and RhinoCam in setting the work zero. It would be much more intuitive and most importantly does not require moving the model below the construction plane which I believe for most people is at 0,0,0 and things are built on top of it. That's my two cents worth.

    Thank you again for looking into this problem for me.

    To me Origo is the natural way of the working with the model. Same behavior in all the expensive licenses I've owned or used over the years (MasterCAM, SolidEdge, Rhino/MadCam...).
    On the other hand, I very rarely have a negative toolpath. My machines are calibrated with zero on the table.



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    Default Re: Z needs to be negative to cut from zero which is top of part. How to configure?

    Where is your model in relation to xyz zero?

    In Rhino you will move the model. If you are nervous about screwing something up then do this. Copy your model and paste the copy in the same location. Now go to layers and select
    Change object layer and create a new layer and name it original.
    Now go to layers and turn iff the lightbulb.

    Now your model on the screen can be changed is moved and the original is still there.

    Put a single point where you want xyz zero.

    Go to the command move. Select the whole model and with osnap on points grab the model by the point and move it to 0,0,0

    That point is where you will zero mach3.

    Select the model in madcam and create your toolpath.

    The toolpath will be correct. It wont matter if the numbers are negative or positive because the cutter will follow the path



    Sent from my iPhone using Tapatalk



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Z needs to be negative to cut from zero which is top of part. How to configure?

Z needs to be negative to cut from zero which is top of part. How to configure?