pocketing program

In the process of adding the center finding code I discovered a bug in program and fixed it.  In the meantime I've added a small amount of g-code to facilitate cutting center holes in the figures.  (sorry)   Any form that is encoded can be machined out by setting traversals to one and adjusting passesneeded cuttingfeed and cuttingdepth to proceed downward until it cuts the perimeter. This has nothing to do with pocketing aside from the fact that traversals control is needed there.  The addition of a center hole makes the program very handy for lots of other stuff.  Center hole cutting begins once one pass of the perimeter is milled and cutting the perimeter resumes once the center hole has executed the specified number of plunges which is a subroutineparameter passed in with the original call.   I have a screendump of the new stuff which also has the circle/ellipses  Do I just dump that stuff here?  The centerfinding code draws a reference circle overtop of the figure which makes the screen dump look crowded (see the attached picture.

... It wouldn't take much to change every "plunge" in this g-code program into a "leap" for use on a 3d printer to make floors walls and lids for oddly shaped boxes.  I suspect that some 3d printers already do something like this so now all we need to do is figure out how to get g-code to produce annotated drawings (instead of parts themselves) so we can sell the products to our waiting customers?... 

Every shape has a variable named cuttingdepth and if one makes cuttingdepth be negative the endmill goes up instead of down so we'll have to replace the endmill with an extruder if we need to make "precise pieplates".  we'll also need to add a bunch of g-code to run the extruder, (and the heaters/fans?)  .  A g-code driver for that should be available from somewhere, Prusa used to be open source, but could be quite large for implementation here, but its something to think about.

This version makes a log file in the /tmp directory (which gets erased upon reboot). Note the logfile entries look somewhat like g-code linear move with line length and tilt appended to its end.  the line origin and endpoint are listed for each line in the figure. Copy just the g-code entry into the system clipboard (after displaying or editing the log file in a linux window). Mouseover the MDI execution rectangle and  depress cntrl shift and h keys together, the clipboard will be deposited into the MDI history window just above. The g-code can be executed by mouseing it into the execution rectangle and then mousing its go box. This let you re-visit any line in the figure (perhaps to check for interference problems, I use this method to measure saw tooth rake angle) Edit the ngc file to make a logfile in another directory or for another part.   ( Manually select the layer you wish to view in MDI by setting depth)
portion of log file:
g1 f 100.000000 z -0.120000
 g0 x 2.000000 y 1.000000 len:0.521875 8.000000
 g1 f 100.000000 x 2.516796 y 1.072631 len:0.521875 8.000000
 g0 x 2.516796 y 1.072631 len:1.939508 105.731904
 g1 f 100.000000 x 1.990925 y 2.939487 len:1.939508 105.731904
 g0 x 1.990925 y 2.939487 len: 1.939508 270.268096 ....

   attached find a screen dump of /tmp/isotri.ngc . This file was generated by an execution of polygonpockete.ngc (zipped).  My original goal was to make a log file which listed origin, endpoint, length and tilt of every line in my pocketed figure. This could be used to take advantage of highlighting in the MDI window on my version of linuxcnc.  Length and tilt are stored as comments on lines in the log file where a g0 gcode command to the line's origin and a g1 gcode command to the line's endpoint executed in a MDI window highlights an individual line after the execution ofpolygonpockete.ngc and an erasure of the lines it already highlighted.  To my  surprise the MDI window ignored the length and tilt following the ; and the linuxcnc interpreter went right by the g0 gcode command and executed the list of lines like it was a gcode program, a program containing lots of nasty numbers instead of nasty trigonometry. You'll have to edit polygonpockete.ngc to put the log file where you want it, see (logopen, (log, and (logclose)  The logfile does not contain any curved lines, nor does it contain the shortlines I put into polygonpockete.ngc to discourage the linuxcnc trajectoryplanner from rounding over the vertices.

1. fix bug in last side tilt angle  2. punch a ridiculous number of holes around the edges of the figures in the collection using an external subroutine. (makeholehere.ngc, included in the zip)