Strange 3D Toolpath Simulation

[NancynBob (Bob Griffith)]

Working on Christmas ornaments now rather than starting in December like last year. Attached, I hope, is a screenshot of part of the simulation.

Notice the two nearly parallel “border lines”. The outer one is created by 3D Rough using a 1/8" end mill. The inner line is from 3D Finish with a 1/16" ball nose. On other stuff like this, the Finish Pass essentially wipes away the Rough Pass. I haven’t tried cutting this yet, but am wondering if this is just a glitch in the Simulation or if I have a different problem. I’ve tried tweaking a number of things but nothing has changed the Simulation appearance.

Also attaching the cd2 file.
Come Let Us Adore Him.c2d (928 KB)

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

Only a very small tool would be able to fit in and cut this:

You are using a #102 DEFAULT for roughing (I’d suggest using a #102 tool definition for the material you are cutting):

and you are limiting the 3D Roughing toolpath to:

which, since 3D toolpaths are calculated to the centerline of the tool is effectively:

Apply:

If you then draw in a circle the diameter of the tool:

you can see why it didn’t fit.

If you want a consistent lip around the design, then you should include it in the 3D model, or cut using “normal” toolpaths, say a series of Advanced V carving toolpaths w/ pocket clearing.

Note that this will require that you draw up the design in profile so as to work out how much the geometry for each preceding level should be inset.

Start with the top level, the star:

Then, draw the tool and the stock in profile:

and the thickness of the cut:

and measure to get the needed offset:

Apply

Then add the element for the next level (the staff):

and cut the next level:

Then, offset again:

OK

(the angle and offsetting and so forth will require a bit of adjustment)

At this point a V carving may be assigned to the text:

Again, note that the angle of the tool or the position of the text or the thickness of the layers will need to be adjusted:

Alternately, just model the stock thickness in…

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

Apply

which will then cause the 3D toolpaths to be limited to where material is removed:

but note that you will need to use a tool small enough to remove the small details, and long enough to cut as deeply as is needed:

[NancynBob (Bob Griffith)]

Thanks.
I kind of understand and kind of don’t. My biggest puzzle was why the 3D Rough apparently was cutting further to the outside that the 3D Finish.

The hiccup near the star I took care of by simply moving the star a few 1/00’s.
Since part of design is to leave a raised border about 1/10" wide at full height (3/8") I decided to try adding that border within the Model function. Selected the inner and outer border lines and then created a Flat, Ht .375, Equal.
Since I don’t want the Model to do the final cutout (especially when creating a bunch of these on one board) I’ve let the outer border be the controlling vector for the 3D toolpaths.
It looks like using the 2D Contours, the simulation looks like it will do exactly what I want.

Another Learning Experience!