On Feb 3 2013 3:42 PM, Peter C. Wallace wrote: > On Sun, 3 Feb 2013, John Kasunich wrote: > >> Date: Sun, 03 Feb 2013 17:08:37 -0500 >> From: John Kasunich <jmkasun...@fastmail.fm> >> Reply-To: EMC developers <emc-developers@lists.sourceforge.net> >> To: EMC developers <emc-developers@lists.sourceforge.net> >> Subject: Re: [Emc-developers] custom EDM configuration questions >> >> >> >> On Sun, Feb 3, 2013, at 03:59 PM, EBo wrote: >> >>> >>> possibly, but a more principled hack would be to interface it at >>> the >>> point where it calls the low lever Catmull-Rom spline, and just >>> evaluate >>> it in reverse. I do not know how difficult that would be, but it >>> would >>> require the ability to move in the negitive direction. I have >>> written >>> things like this for moving along splines with custom code, but I >>> would >>> have to look into how to do this in EMC-s low level motion >>> planning. >>> Probably the easiest thing to do would be to set up a >>> "reverse-motion" >>> pin in HAL, and then evaluate it internally, or modify the adaptive >>> move >>> command to allow positive/negitive feedback voltage which would >>> imply >>> forward/reverse of motion. Anyway that is my thought off the cuff. >>> >> >> Where things get ugly is when you try to do this in a general way. >> For >> example, what happens if you ask for negative feed while in a >> spindle >> synchronized move (single-point threading or rigid tapping)? >> Actually, >> that issue must have already been dealt with - adaptive feed would >> cause the problems in that case even for positive scale factors. >> But >> that was just an example. What about probing moves? What about >> the blend between successive non-co-linear straight lines? What >> about >> a profile that consists of many 0.002" long lines? Can you back up >> more than 0.002"? >> >> Sure, you can say "an EDM will never make a spindle synchronized >> move", but changes to the motion module need to do sane things >> regardless of what kind of a machine is being controlled. >> >> > > What about different motion modules optimized different classes of > applications?
Sure if you can describe realistic situations... ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_jan _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
