Would like to eliminate double passes on contiguous sides of multiple hexagons

[vsedinger (Victor Sedinger)]

I’m attaching a CC file representing my question. Is it possible to keep the cutter from going over adjacent sides twice. Hopefully I’m making my question clear enough.
When I join the hexagons to make a honeycomb pattern, the tool path creates individual hexagons, but since they adjoin, the cutter goes over mutual sides twice. Running the simulation shows that these unnecessary passes lengthen the project time.
Is there a way to program the file so that contiguous sides only cut once?

*Hex honeycomb.c2d (52 KB)

Thanks,
Victor Sedinger

[WillAdams (William Adams (Carbide 3D))]

Yes, if you can work up a continuous path (or series of continuous paths) which only traverses each segment once.

Create Polyline

click along intersections until one creates the desired path

(it may help to turn off Snap to Grid)

It seems pretty obvious that you will need at least two separate paths (proving that would be an interesting bit of mathematics)

I’m going to go with more than two…

13

Attached as a v8 file.

_Hex honeycomb_contour_V_v8.c2d (60 KB)

Actually doing this as a V carve is a different problem/solution, hang on for that.

[WillAdams (William Adams (Carbide 3D))]

Draw up the tool/cut in profile (or do the trigonometry to determine the necessary width)

OK

Ungroup

Select non-contiguous elements:

![image|690x414](upload://4vUx9p85nZatwHdIbmhQaiuFD6z.png

Apply

Repeat this until all hexagons have been inset, where necessary, draw in/create geometry:

Select the original geometry and Boolean Union so as to get the perimeter:

OK

Offset to the outside:

Sharpen up the rounded off corners by measuring the rounding:

then creating a hexagon of that height:

and dragging it into alignment:

and Boolean Unioning it:

OK

Repeat for each other corner, where necessary, manually lining things up, or trimming after the Union:

OK

repeating until one arrives at:

Select

and delete the offset geometry

Select everything:

and assign a V carve toolpath:

OK

Attached as a v8 file.

_Hex honeycomb_Vcarve_v8.c2d (64 KB)

[Randy (Randy Gordon-Gilmore)]

@vsedinger

Is there a way to program the file so that contiguous sides only cut once?

Victor, Will has provided excellent (as always!) methodology for machining your honeycomb.

It is geometrically impossible to cut the honeycomb grid in a single pass without lifting the cutter (as in the famous “draw the envelope without lifting the pencil” problem) because each “node” where the cell edges come together has 3 lines converging. While machining, two of those lines will be an “in-out” pair, leaving the third line as a dead-end orphan.

To machine the honeycomb in the least possible time, you could do a 3-directional array (i.e at 0, +60 and -60 degrees) of cut-jump-cut-jump passes (i.e. alternating G1 and G0). There is still more movement than the actual cutting, but the extra moves are rapid moves so they would take less time.

[vsedinger (Victor Sedinger)]

Thanks, Will. Extra mile service as always.

[vsedinger (Victor Sedinger)]

Thanks, Randy.
If I understand correctly, I’m drawing polylines at 0, 60, and -60. Then copy the group, flip vertically, and join the end nodes.

[Randy (Randy Gordon-Gilmore)]

Victor, I’ve re-thought my approach. Here is my revised concept.

Actually, they are both parts of one toolpath, with a rapid move between “end” of “1st PASS” and “start” of “2nd PASS”

Of course, it has taken me at least 8 times to work out and draw this, what it would have taken just to accept double-passes by patterning a single hexagon…

This actually takes me back to my brief time programming waterjet toolpaths, where I drew them manually in BobCad… Thank you for the memory!

Randy