Looking at the pictures I really love the PDP-8 in one of them... Thanks for the links!
On Feb 3 2013 8:44 PM, sam sokolik wrote: > there was a guy on irc that converted an wire edm to linuxcnc using > adaptive feed. I thought it worked pretty well - he had posted > pictures > of stuff he had cut... > > his handle on irc was mdynac > > a post by him on cnczone.. > http://www.cnczone.com/forums/463833-post31.html > > oh - found the pictures - cradek hosted them... > http://timeguy.com/cradek-files/emc/edm/MVC-029S.JPG > http://timeguy.com/cradek/emc/edm > > So - it seems doable.. Seems the wire breaking issue could just be > back > up and RFL... > > And remember - Linuxcnc keeps getting better and better... > > sam > > > On 02/03/2013 09:20 PM, TJoseph Powderly wrote: >> On 02/03/2013 07:47 PM, EBo wrote: >>> 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 >> i've written and investigated Linuxcnc for EDM for years now >> maybe this will be of interest >> >> there are 3 basic forms of edm and each has unique needs >> >> all are EDM though and cannot tolerate the 'in position on time' >> nature >> of linuxcnc ( needs a different rule set for where the tool tip must >> be >> now ) >> the tool tip must be in a position dictated by the process, >> independant >> of time and independant of the position where we were last check. >> >> the 3 types of edm are ( besides edg and a few even rarer modes) >> 1) hole drilling... only moves along a single axis. usually a >> single >> joint >> 2) sink edm ... retracts to a given point >> ( maybe 3-8 axis, maybe 1, but the retract path is not >> neccesarily >> the approach path ( nor often the same )) >> because it retacts to a safe point, this is 'sky blue', you >> need'nt >> have begun or been there before, its just safe >> 3) wedm.. retracts along the programmed path thru one or more >> path >> pieces >> ( multiple gcodes/ multiple sequenctial tangential geometric >> entities) >> this requires a memory ( at least waypoints, like the segments >> spit >> out by the traj planner ) >> >> 1 & 2 are HAL solvable >> 3 requires changes to linuxcnc position planning ( at least a >> history >> that can be un-done, like gps waypoints ) >> >> my own tests are only for sink edm ( some for hole poppers but my >> HiPresure pump is down now ) >> >> i suggest something much simpler than the >> VtoF to HAL to thresholds to motion proposal >> i simply use a window comparator and output ADVANCE or RETRACT >> signals >> to hal >> >> hal knows the beginning and ending positions (limits) of the motion >> and an OFFSET component's input is inc'd/dec'd according to the >> process >> ( according to the window comparator ) >> >> the machine cannot exceed the depth programmed ( could be x y z c as >> you >> like ) >> so it has 'spark out' with a little hal-foo and timer ( or a higher >> threshold in mine ) >> It is not locked at the bottom, simply watch for it to be at the >> bottom >> for a len of time w/o backing off... thats a sign the work is really >> completed >> >> the cut could go bad and retract to the RETRACT limit, and I abort >> at >> that point >> ( no where to run ) >> >> the cut could get done and spark out at the bottom >> >> right now i'm playing with feeding JMK's sine/cosine stepper example >> to >> implement orbiting from this lower 'roughing point' >> >> i specialize in sink edm. I just rebuilt 2 OKAMOTO's that were >> terribly >> dead and abused. >> they cut fine now. I wrote all the macros for ELox system 8/9/10 >> fanuc's >> i wrote all the code for AGies during the 1980's >> i wrote all the PLC and macros for Strathclyde & EDMsolutions cnc >> edm's >> i wrote the software that generates all the cutting tables ( etables >> ) >> for them also >> now I've re-written all the user macros for OKO's too >> circular vectoring spherical in any axis, subgates and back >> tapering, >> copper/graphite in many material combos >> >> blah blah blah i knows a S^&%&load about cnc edm >> >> i think the F2V is overload and too slow, yes the process is slow, >> but >> the intelligence is fast. >> you can advance slow but you better run away NOW and FAST >> >> i've posted it all too many times, schematics, code, ini's , hal's >> nuff said >> just seems like a old story that nobdy listed to anyways >> >> tomp >> tjtr33 >> >> >> ------------------------------------------------------------------------------ >> 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 >> > > > > ------------------------------------------------------------------------------ > 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 ------------------------------------------------------------------------------ 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
