A library for 2.5D CNC.
- A XY-coordinate is represented as
(X . Y). - A XYZ-coordinate is represented as
((X . Y) . Z). - A PATH is a
LISTofabsoluteXY-/XYZ-coordinates. INNER and OUTER paths are derived from an XY path by applying an offset of radius R to it, which corresponds to the radius of the CNC end mill. - For graphical representation, a XYZ path will be represented as a
VECTOR FLOATofverticescalledVPATH. - A PATH SEGMENT is a
CONSofabsoluteXY-/*XYZ*-coordinates. - A TAG is a PATH SEGMENT, where a TAP, i.e. a path gap in Z direction, shall be located in the milling path.
- A TICK is a tiny PATH SEGMENT pair that pushed forth and back into a XY corner.The purpose of a TICK is to avoid manual post-processing of a milled piece. They are currently only implemented for 90⁰ XY aligned corners.
Generated GCode is intentionally reduced to linear, incremental segments. Curvatures are handled by means of pre-processing with the tools of this library.
CPATH like (inc-coord . abs-coord), maybe containing the line indeces and GCode lines as well, for repositioning the mill during machining.
(require :asdf)
(asdf:load-asd "/home/dev/projects/cnc-builds/cnc-builds.asd")
(asdf:load-system :cnc-builds)
;; basic regression tests
(paths/tests:run-tests)
;; visual regression tests
(paths/tests:run-view-tests)
run-view-tests covers main XY paths configurations, among them:
- Layout of a fingerjointed box
- Ticked outline of a fingerjoint face
- A closed spiral, e.g. for pockets, and filled rectangle, e.g. for surface planing
emitt-gcode-xy-z takes a list of incremental XYZ coordinates, for which the GCode is generated with speed settings F for XY and FZ for Z directions.
convert-path-dxyz% generates the list of incremental XYZ coordinates considering taps. Its internals do not allow for integrating TICK, for which it was deprecated.
(in-package paths)
(defparameter path (car paths/tests::tbox))
(defparameter tags
(remove-if #'(lambda (c) (< (euklid (c- (car c) (cdr c))) 6.)) (group-2 path)))
(with-open-file (f "~/share/test2.nc"
:direction :output :if-exists :supersede)
(format f "G21~%G91~%")
(dolist (ln (emitt-gcode-xy-z
(convert-path-dxyz% path tags 1. -1. 5) -0.5 1200))
(format f "~a~%" ln)))The correctness of the generated GCode may e.g. verified with the visualizer of the Universal GCode Sender:
The TAPs are visible e.g. right below of the yellow cone and left of the “4 mm” marking.
- Construct a XY path with
(car paths/tests::tbox) - Calculate the OUTER PATH for an endmill of radius R by
(shift-path-- r ...) - Remove duplicate path points and join colinear path segments
(optimize-path ...) - Close the path
(close-path ...) - Add the ticks
(inner-ticks r ...)
- Select the four longest path segments as tags
(subseq (segments-by-length path) 0 4)
- Combine the derived ticked XY path with the selected TAGs using
(expand-path path tags 2 -1.5 5 2)
(with-open-file (f "~/projects/relays-ui/assets/data.csv"
:direction :output :if-exists :supersede)
(let* ((r 1.5)
(p (close-path
(optimize-path
(shift-path-- r
(car paths/tests::tbox)))))
(path (inner-ticks r p))
(tags (subseq (segments-by-length path) 0 4))
(i 0))
(multiple-value-bind (v l-vec)
(expand-path path tags 2 -1.5 5 2)
(do ()
((= i l-vec))
(format f "~3$;~3$;~3$~%"
(aref v i) (aref v (1+ i)) (aref v (+ i 2)))
(setf i (+ i 3))))))The resulting XYZ path may be visually verfied e.g. with relays-ui: