On Friday 21 March 2014 13:59:04 Marius Liebenberg did opine: > On 2014-03-21 18:17, andy pugh wrote: > > On 21 March 2014 15:50, Marius Liebenberg <mar...@mastercut.co.za> wrote: > >> Very straight forward really. Not a standard lathe but a custom made > >> to cut plastic. Looks much like a wood lathe with two chucks. Linear > >> slides along the Z axis with a chuck at each end. One X axis with > >> permanent tools set up at both ends of the tool holder. > > > > I am sure that the description is very clear to you, but I can't yet > > work out if the spindles turn in the same direction, or if the tools > > for each spindle operate on the same or opposite sides of the work. > > The spindles can be activated independently and also change direction > independently form each other. The tools work on the same side so one > will spin clock wise and the other anti clockwise for the same job > > > It seems like you should just be able to change coordinate systems and > > use negative Z values. > > > > If you want Z to be positive away from either chuck, depending on a > > mode change, then how do you allow for the fact that the Z-axis > > position is out by a couple of feet when you switch modes? > > What do you want to happen when you do switch modes? If Z = 10 is 10mm > > from one spindle and you change mode, do you want the tool to > > instantly shoot to within 10mm of the other spindle? > > > > How do you want to inform the system which spindle you are working > > with? > > The change over from one spindle to the other will happen as a move to > the centre of the lathe where the reference position will be. There will > be code in the beginning of the job loop to probe the material and then > run the gcode from there. So I envisage some python code to control the > spindles via hal. The solution will have a gladevcp panel with cotrols > on it. Probaly to select the right spindle and to swap the coordinate > system. That is why I want to keep the gcode as one file and do the swap > in some other fashion. I was hoping to use MDI to swap the coordinates. > > I am sorry I am not close to the machine so I cannot send a picture of > it.
I think this is a case where I would write the code to multiply the Z value by a named variable. Then use the mdi facility to set that named variable to either 1 for normal, or to -1 for the right hand spindle. I checked the G10L2, and G17-19.1 on the wiki just now, but the G10L2 code seems very specific in that the R rotation is using the Z axis as the point to rotate about. One could even put it in a make so many parts loop, where the code itself sets the named var, then calls the subroutine that makes that part. That of course is not the only choice, but I hate writing code, so I would much rather do that control in the parent routine and have just one subroutine to actually make the part. Is this thing open enough and safe enough to be around while running that you can be changing the finished part out for the next piece of plastic on the spindle currently stopped? That would almost be a lights out job if a robotic changer could be fabricated that could reach both spindles. Repetitive tasks are what machines are good at, but humans get bored doing. And when humans get bored, they make mistakes. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
