[Emc-users] Curves in ZR plane.
If you had a machine with conventional XYZ and a radial cutter motion too. (For example a HBM like my dad's) https://picasaweb.google.com/lh/photo/lorjlRbUi9B2VQy0Cd0KcNMTjNZETYmyPJy0liipFm0?feat=directlink If that was CNC you could bore spherical cavities and external radii. I guess that the radial slide on the chuck would be a U axis (then a V axis then a U axis...). LinuxCNC can't do G2 G3 in the ZU plane. So how would you set up such a machine? I guess you could make cartesian moves in VYZ and curves in XZ? Would this be the method of choice? Viewing the machine as in inverted lathe rather than a milling machine this nomenclature makes an amount of sense. Is the inability to do curves in anything but the XY YZ and XZ planes deeply hard-coded, or would it be a trivial modification to add? (XY, XZ, XU, XV, XW, YZ, YU, YV, YW, ZU, ZV, ZW, UV, UW, VW is rather more planes than fit comfortably) -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curves in ZR plane.
If someone is going to modify the circular interpolation code it would be nice to be able to specify a vector normal to the plane of interpolation. G17,G18,G19 would still work but maybe a g17.1 or g117 would allow three values corresponding to the normal vector. G17.1 I J K G02(3) X Y Z R (IJK) or without the G17.1 I J K G02(3) X Y Z R I J K The vector could be derived using the start point, end point, radius value and a value to determine the planar rotation from one or more of the orthogonal planes. G02(3) X Y Z R A(B)(C) Best: (heh - my opinion) :) The IJK values from the start point to the radius center point would also allow calculation of the normal vector. Using the IJK (ie: G02(3) X Y Z I J K) to determine the 3D space location of the center point would then determine the normal vector for interpolation motion. Calculating the normal vector using the one added value on the line would require the least programming changes. On Tue, Nov 6, 2012 at 5:41 AM, andy pugh bodge...@gmail.com wrote: If you had a machine with conventional XYZ and a radial cutter motion too. (For example a HBM like my dad's) https://picasaweb.google.com/lh/photo/lorjlRbUi9B2VQy0Cd0KcNMTjNZETYmyPJy0liipFm0?feat=directlink If that was CNC you could bore spherical cavities and external radii. I guess that the radial slide on the chuck would be a U axis (then a V axis then a U axis...). LinuxCNC can't do G2 G3 in the ZU plane. So how would you set up such a machine? I guess you could make cartesian moves in VYZ and curves in XZ? Would this be the method of choice? Viewing the machine as in inverted lathe rather than a milling machine this nomenclature makes an amount of sense. Is the inability to do curves in anything but the XY YZ and XZ planes deeply hard-coded, or would it be a trivial modification to add? (XY, XZ, XU, XV, XW, YZ, YU, YV, YW, ZU, ZV, ZW, UV, UW, VW is rather more planes than fit comfortably) -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- dos centavos -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curves in ZR plane.
On Tue, Nov 6, 2012 at 5:41 AM, andy pugh bodge...@gmail.com wrote: If you had a machine with conventional XYZ and a radial cutter motion too. (For example a HBM like my dad's) https://picasaweb.google.com/lh/photo/lorjlRbUi9B2VQy0Cd0KcNMTjNZETYmyPJy0liipFm0?feat=directlink If that was CNC you could bore spherical cavities and external radii. I guess that the radial slide on the chuck would be a U axis (then a V axis then a U axis...). My experience tells me the determination of the symbol (XYZABCUVW) of the slide axis on the rotary motion is determined by the position of the slide when in home position. In reality you could assign any symbol to it but then talking about it to others would result in the need to explain it in greater detail for the other person to be able to understand. The only requirement is to match the symbols of the machine motion elements to the symbols in the NC program. During machine movement the symbol would not change from U to V just because the orientation changes unless the NC program requires the change. I think this would be VERY difficult to program. LinuxCNC can't do G2 G3 in the ZU plane. So how would you set up such a machine? I guess you could make cartesian moves in VYZ and curves in XZ? Would this be the method of choice? Viewing the machine as in inverted lathe rather than a milling machine this nomenclature makes an amount of sense. Is the inability to do curves in anything but the XY YZ and XZ planes deeply hard-coded, or would it be a trivial modification to add? (XY, XZ, XU, XV, XW, YZ, YU, YV, YW, ZU, ZV, ZW, UV, UW, VW is rather more planes than fit comfortably) -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- dos centavos -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curves in ZR plane.
On 6 November 2012 13:31, Stuart Stevenson stus...@gmail.com wrote: The IJK values from the start point to the radius center point would also allow calculation of the normal vector. Using the IJK (ie: G02(3) X Y Z I J K) to determine the 3D space location of the center point would then determine the normal vector for interpolation motion I think this works as long as you assume less than 180 degrees of arc and have identical behaviour for G2 and G3. I don't see how you can derive the normal vector from three points to give G2 and G3 a meaning. You would have to raise an error in cases where the three points lie on a line. G16 appears to be available for setting this mode, and even makes sense as the zeroth member of the set. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curves in ZR plane.
On 6 November 2012 16:56, andy pugh bodge...@gmail.com wrote: I guess that using an UXZ se UYZ, in case anyone was confused. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curves in ZR plane.
On 6 November 2012 13:44, Stuart Stevenson stus...@gmail.com wrote: During machine movement the symbol would not change from U to V just because the orientation changes That was intended as a joke :-) I guess that using an UXZ set for positions is simple enough. It will be a unique config for the machine in question anyway. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curves in ZR plane.
Andy; You would have to raise an error in cases where the three points lie on a line. G16 appears to be available for setting this mode, and even makes sense as the zeroth member of the set. 3 vertices doth make a triangle; should two of those vertices be equal, one hath a degenerate triangle (i.e., a line), should all 3 vertices be equal, one hath a really degenerate triangle, called a point. My 3D rendering code uses Quaternion SLERP to go from one point to another. (Wikipedia is, of course helpful here) If you want to see the code, one can see it; http://freewrl.sf.net, or, sneaking around the back http://freewrl.cvs.sourceforge.net is the full code base. For Android devices, I'm adding a STL front end to it, and planning to add many more neat features, but I'm charging a minimal amount for it. (no app name here, but if you look for it on the google app store, my name is a clue) I mention this because, yes, getting a normal from 3 vertices can be slightly problematic, but that's a simple check. Also, SLERP code is available, written in C, as well as all kinds of functions, etc. I'm still learning GCode, so G16 is still a blur to me. Regards; John Alexander Stewart. -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curves in ZR plane.
On Tue, Nov 06, 2012 at 07:31:07AM -0600, Stuart Stevenson wrote: Best: (heh - my opinion) :) The IJK values from the start point to the radius center point would also allow calculation of the normal vector. Using the IJK (ie: G02(3) X Y Z I J K) to determine the 3D space location of the center point would then determine the normal vector for interpolation motion. Calculating the normal vector using the one added value on the line would require the least programming changes. I don't understand what you mean. Can you elaborate in mathspeak? I think andy thinks you mean calculate normal as (XYZ - current) cross (IJK - current) which he rightfully says flips direction given an arc of more or less than semicircle, and for semicircle and full circle it's indeterminate. Also the third (normal to selected plane) component in XYZ is currently used to give a helical offset, and that will mess up your normal with the above scheme. Can you give a more detailed spec that handles helixes, semicircles, and full circles? Perhaps even make a wiki page we can all work on? As you probably know, arbitrary nonplanar helixes are already supported in the trajectory planner and other layers past the interpreter and canon. It's the gcode that makes it tricky. In fact, interested folks might want to check out http://git.linuxcnc.org/gitweb?p=linuxcnc.git;a=shortlog;h=refs/heads/arbitrary-arc -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curves in ZR plane.
On 6 November 2012 17:48, Chris Radek ch...@timeguy.com wrote: I think andy thinks you mean calculate normal as (XYZ - current) cross (IJK - current) which he rightfully says flips direction given an arc of more or less than semicircle, and for semicircle and full circle it's indeterminate. Though having said that, one can at least be consistent in assuming that start-end-centre are a clockwise triangle. (but that does flip as the arc becomes 180 degrees). I think clockwise numbering is how STL defines face normals. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
