Pocketing with finishing in complicated profiles

[LCform]

pocketing with finishing is not possible in FAGOR C8055 if the profile is very complicated and the pocket is open from some sides. Since the mill should move along the edges of the pocket while in some parts there are no edges, meaning that the poeckt is open in some parts, so literally the mill should exit the piece to remove the material from the edges and then also come back in and continue cutting the pocket. I have put also this example so you could have an imagination. You can assume a dimension and a mill diameter. And then respectively a finishing thickness to be left for the finishing operation. Since I did not use the CNC coding, cause I have not practiced it yet, I have to define a profile that would do what I have defined above. Just that I was wondering that the machine was giving strange errors while I was defining the profile, where the mill would get out of the pocket, maybe because the profile was a polyline, and whenever the mill would not touch correctly a profile line, I mean if the profile was not geometrically possible for a certain mill to pass, it would give error. This was logic, but sometimes I would see despite that the mill would fit in the profile, it was still giving error. Unfortunately now the profile is corrected and I can not remember where the error was. But now what I would like to know is: how a CAM software would define a cutting path for this shape and which would be the difficulties for this kind of shape. I also upload the example file, you are free to change any dimension to indicate any possible difficulty you think. Because I could not guess what was the problem that the CNC machine was not accepting the actual profile of the pocket.

 

[ornerynorsk]

Semantics, but this is profiling or "boss" cutting, not pocketing.

With that out of the way, there are many possible ways to get interferences in CAM whilst still having actual correct cutter diameters and allowable clearances. For example, if you are cutting full depth, the CAM is seeing the tangent points of your fillets as the programmable limits with sharp corner tooling, have you given the tools adequate corner radii, in reality and in the tool edit? Also, are you calling out excessive roughing stock allowance, which will also set back toolpaths and cause possible interference. These are the 2 most common issues I see when a programmer is having problems, there are certainly many others. Flute length errors, tool OAL and toolholder dimensional errors, etc. Just a couple thoughts.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.