What is a pre-finished surface?
A pre-finished surface is a face of the part that is already at final finish and dimension before using CAM Assist – meaning you don’t need or want CAM Assist to cut it. This could be because that face was created by a previous operation (like a prior machining op, casting, or grinding) and should not be machined further. In CAM Assist workflow, you would mark such surfaces or simply not include them in the toolpath generation so that they remain untouched (no roughing or finishing passes). CAM Assist will then treat these as surfaces that require no machining. Essentially, it’s telling the AI “this face is done, leave it alone.” For example, if you have a part where one side is already milled flat to spec as part of stock prep, that side is a pre-finished surface.
Why is identifying pre-finished surfaces important?
You don’t want CAM Assist to waste time or possibly ruin a surface that’s already perfect. If a face does not need machining, machining it could only do harm (or unnecessary work at best). By marking pre- finished surfaces, CAM Assist can focus only on areas with stock to remove, improving efficiency and avoiding potential damage. It also helps the AI understand the initial stock condition better – if some surfaces are at net shape, it essentially knows there’s no stock there, which can influence how it generates surrounding toolpaths. It matters in instances like parts that come from near-net processes (casting, forging) where some faces are as-cast but within tolerance so you leave them, or parts that have been partially machined in another program (maybe you’re doing op2 and some faces from op1 are final). Another scenario: maybe you polished or anodized a face and do not want it touched in a later milling op. Marking it pre-finished prevents an accidental scratch. By excluding such surfaces, you also shorten CAM Assist’s runtime and program length, as it won’t create toolpaths there.
Where do I find / adjust pre-finished surfaces in CAM Assist?
You will find pre-finished surface information in the Assess phase of CAM Assist. When you launch CAM Assist, the Assess phase will commence and should it identify any pre-finished surface, it will highlight these as warnings in the Assess panel.
You can't adjust pre-finished surfaces in CAM Assist - you will need to return to your CAM package and make changes to your setup.
How else are pre-finished surfaces known in CAM Assist?
- Non-machined face
- Already finished face
- Do-not-cut surface
Related articles to pre-finished faces
- What is finish full part? (with that off, you decide which faces to finish, presumably skipping pre- finished ones)
- What part data is stored by CAM Assist? (pre-finished surfaces might factor into data like stock condition but not directly relevant)
- What causes CAM Assist to not finish certain faces? (if a face is pre-finished, CAM Assist would intentionally not finish it, which would appear as an unfinished face in output but it's by design)