1 Finished part
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Examples: · · ·
The line groups are numbered on the drawing. Group 1, the outermost, is the outline: the edge of the blank, which is already to size. For each of the others, say whether it is an island, a pocket or an engraving. An island is left standing to Z0, and everything round it, out to the group it stands in, is cleared down to its Z (e.g. -4). A pocket is cut down to its floor Z (or tick Through). An engraving is cut by the cutter following the line down to its Z. A ring inside the outline with a group inside it is a moat: the ring is the pocket (its Z is the moat's floor) and the group inside it the island, which needs no Z. Open lines are engraved. All Z are at or below 0, so 4 is taken as -4.
Set every group to: · · · ·
2 Blank (stock)
Show the blank
A blank from a STEP file can be a part already machined (an earlier op, another cutter): only what it still has on it over the finished part is cut.
3 Feeds and speeds
Show the feeds and speeds
Starting points from the usual published tables for end mills, at the gentle end for a manual mill. There is no flood coolant: cutting oil is brushed on by hand, so the cutting speeds are turned down from the tables (by 10–40% in metals, more for HSS than carbide; not at all for acetal and brass, which cut dry), with the chip load per tooth kept. They follow the material, HSS or carbide, the flutes, the slider and the prime cutter's type and diameter in card 4. The speed is the fastest of the mill's speeds that doesn't run the cutter more than 10% over the recommended cutting speed; pick another from the list and the feeds (mm/min) are worked out from it. The speed isn't sent to the machine: it is set by hand, and written as a comment at the top of the G-code when ticked. Ticked, the stepovers, stepdowns and feeds go into card 4 and follow any change here or to the cutter; changing one of them in card 4 unticks it.
4 Machining
Show the machining settings
Prime cutter
The stepovers, stepdowns and feeds are filled in from card 3 (Feeds and speeds). Changing one of them here unticks it there.
With an allowance above 0, roughing stops that far off the walls/floors and the finishing below takes it off.
Finishing parameters
Show the finishing parameters
Stepdown zones
Finishing uses its stepdown per level unless the height falls inside a zone. Inside a zone, it uses the zone's own stepdown. This gives finer levels through fillets and chamfers. Heights are in work Z, so for a 1 mm top fillet with Z0 on the blank top, enter 0 to -1. Levels also land on each zone's ends.
Once roughing has stopped at the wall and floor allowances, finishing takes them off with the prime cutter at these settings, level by level. There is no tool change (it would disturb the Z offset). Unticked, the allowances are taken off at the prime cutter's own settings.
Wall and floor allowances are 0, so there is nothing left for finishing to take off.
3D finishing parameters
Show the 3D finishing parameters
Raster finishing uses the prime cutter (no tool change: it would disturb the Z offset). A ball nose gives the smoothest finish on curved and sloped surfaces.
Heights
5 Program setup
Show the program setup
Settings changed since the last run: press Generate toolpaths to update.
6 Preview
Hide the preview
Load a part to see it here.
Cutter check
Drag to rotate · right-drag or shift-drag to pan · scroll to zoom. Grey = part, outline = blank, thin red = rapid moves.
7 G-code
Show the G-code
Controller not yet confirmed: output uses only G0/G1/G17/G21/G90/G94/M0/M30 (and M3/M5 if ticked). Z is the tool tip. Always dry-run above the work first.