Creating a contour cleanup pass

[DavidInCO (David Cottrell)]

Haven’t gotten my machine yet, but in prep I am purchasing some files for projects I would like to try. In these files there are C2D files as well as Gcode files and PDF’s with the tool path setups. I am noticing something pretty cool in these setup files.

When cutting a contour, there is apparently a setting in the software that was used for “Stock to Leave”. I notice this is set to a value of 0.01 on the initial cut. Then a full depth cleanup pass is done with the same endmill and the “Stock to Leave” value is adjusted to 0.0. I am sure this will remove all tool marks and leave a clean edge.

My questions are these:

• Will I have to use two different vectors to create a similar effect in or does carbide create have a similar setting that I am missing somehow?

• If not, is it available in the pro version?

• Or, to get features like this am I going to have to learn Vectric?

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

In CC Pro 3D Roughing passes have a “Stock to leave” option:

For other toolpaths it will be necessary to offset geometry:

Adding geometry to cut as a pocket with a finishing pass

One technique which is often suggested to avoid slotting is to add geometry around a part which one wishes to cut out and cut as a pocket down to tab depth — here’s one technique for that. In this case, the project is a bevel gauge which will be cut out of 0.0625" (~1.5mm) thick aluminum: [bevelgauge] Due to the narrowness of the angles, an 0.03125" endmill has to be used, so after importing and scaling the file (we will be cutting out one which is 3") we select the perimeter and offset it tw…

for X and Y — along Z it is possible to get this effect by adjusting the Depth per Pass, e.g., if one were cutting to a depth of 0.5" w/ a Depth per Pass of 0.125" then 4 full depth passes would be made, but if one reduced the Depth per Pass to 0.124", then 4 full depth passes would be made, and then a fifth which would remove only 0.004" of material.

[DavidInCO (David Cottrell)]

I assume the same principal would be applied when doing a profile cut. Create a boundary that is only say 5 thou greater than the desired final. Use that for the rough, multi-pass clearing contour. Then do a full depth contour cut on the inner boundary where it would shave off the wall of the object leaving clean sides. Less sanding, etc. (for wood, obviously). Is that a valid approach?

[HaroldO (Harold Osmer)]

Much depends on what your end product is, the material used, and the type of finish you will apply. For instance, (using wood) a plywood outdoor sign of 24x24 inches requires less detail edging than an engraved cherry keepsake box. Pine is notorious for leaving edge fluff while maple can come off sharp enough to cut. Epoxy flows are different from spray paint, brush paint, and lacquer finishes. Thus your question is too broad for a single answer.
With experience you will discover that precision passes can do some of the work for you but require more time. Time. Time. Time. CNC is a tool. You cut your piece, trim the excess, sand to remove rough parts, finish as desired. A light pass with some 220 grit will take 20 seconds compared to another full lap around your piece at .002.
Even with metal you will have to beburr to some extent.