Sometimes when I am working with a less than wonderful surface (usually customer provided, but not always) 3D waterline roughing (and finishing) just fails. Other times it takes forever to generate tool paths. Generally I just want to get the material out of there so I can run a finish pass.
I've played with the idea a little bit in the past. Create slices, or silhouettes at the desired depth increments. Then use JK's 2D Trochoidal Milling plug-in to rough out the material. Sometimes it works, and sometimes it seems even with roughing clearance it has issues and over cuts. I think its a CamBam thing from generating the silhouettes. Not a plugin thing. Thank goodness for the Simulate with Camotics Plug-in.
Sometimes the slice and silhouette operations take for freaking ever with those less than stellar surfaces as well.
I was struggling recently with one of those less than wonderful customer provided files. It came as an STP, but it still wasn't great. Usually, customer stp files are cleaner than stl files, but this one was kicking my butt. I had already done some basic manipulation in ViaCad so I went back to ViaCAD and used ViaCAD's tool to project curve to surface. Silhouette in CamBam had taken an hour and I just canceled the operation. In ViaCAD the Project Curve to Surface tool took longer for me to setup parameters and the vector than to execute. I had perfect silhouettes at each level I had drawn a line to project in seconds. Then I exported the curves as a DXF file, and imported the DXF in to CamBam.
Then it was almost child's play to to setup a Trochoidal Milling operations for each depth increment and silhouette I had imported.
As an aside I've generally found its much faster to plunge at a rate that works (very slow) than to spiral to depth.
The simulation with Camotics showed no issues. It will go to the machines as soon as my next order of metal arrives.
