I was wondering the same thing, and is why I asked about some output data. I once had such a discussion with a couple of people only to find that when we instrumented the code the variance of the paths were less that .00002" The machine was not even that tight! The machine I would like to test reverse run on probably cannot even hold .001"
On Sep 12 2015 6:53 AM, Pete_Gruendeman wrote: > Hi: > My boss would suggest that we are slicing the baloney a little > too thin here... While getting the trajectory as exact as possible > in > both forward and reverse directions is important, the practical > limits > of backlash, flexure under acceleration loads, etc. will likely > provide greater error than what is caused by the trajectory planner. > Or am I missing something here? Reversing a path will be most > helpful > for wire EDM, but only to a point. We will always be stuck with the > limitations of the machine. > > I am more interested in sinker EDM but will stay up on your > developments and contribute in any way I can, including test running > software for sinker. > Pete Gruendeman > > -------------------------------------------- > On Fri, 9/11/15, EBo <[email protected]> wrote: > > Subject: Re: [Emc-developers] Reverse Run > To: [email protected] > Date: Friday, September 11, 2015, 11:36 AM > > Hmmm... I can see ways > to cache extra information (like entry and exit > velocities) to get it close/exact, but it would > likely require changes > to the blending > function. I will not have time for that any time soon. > > On a related note, is there > any way we can instrument the code to > generate some statistics on how far it varies > given various normal and > extreme test > cases? A few measurements will trump all the speculation > > (in the absense of mathematical proofs). > > On Sep 11 2015 10:16 AM, > Robert Ellenberg wrote: > > Some > information is saved in the queue structure, but the exact > path > > taken > > by a > parabolic blend (as implemented in linuxcnc) depends on the > > > initial > > > conditions, so you wouldn't really get the same path > played back in > > reverse > > unless you hit it at exactly the same > speed. > > > > Rob > > On Sep 9, 2015 11:21 PM, "EBo" > <[email protected]> > wrote: > > > >> Is it > possible that the motions (including blending) are cached? > > >> Then > >> it > would be a lot easier to roll them back over the exact > same > >> trajectory. Just a > thought... > >> > >> > > > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
