The colours
- Rapid G0 moves.
- Air move a feed move with nothing to cut: completely at or above the safe height, or dropping straight back to a depth the tool already reached at that spot.
- Retract a straight-up move from the cut to the safe height.
- Plunge a straight-down feed move into material.
- Cut every other feed move.
What gets faster
Air moves, and retracts if that box is ticked, get the new feed. Plunges and cuts keep the feed your CAM gave them unless you change it under Programmed feeds. The tool path itself never changes: FeedFix only rewrites F numbers, and adds an F word where a move needs a different feed than the line before it.
Safe height
FeedFix finds the lowest retract or approach height that sits above every cutting move and shows it as a plane in the 3D view. If the stock is taller than the program expects, set it by hand to just above the top of your stock.
The check
Before every download the edited file is read back and compared move by move with the original. If any coordinate, arc or line differs, or any byte other than an F number changed, the download is blocked.
Units
FeedFix shows inches and in/min unless you pick Help → Change to metric. That only changes what you see. Your program keeps its own units (G20 or G21), and a new feed is converted to the file's units before it is written.
Before you run it
Dry-run or single-block the first run of an edited program and keep a hand on feed hold. Most controllers cap F at the machine's maximum feed, so a new feed above your machine's limit runs at the limit.
Mouse and touch
Drag to orbit, right-drag or Shift-drag to pan, scroll or pinch to zoom, double-click to fit. Click a move to jump to its line. Space plays or pauses the simulation.