Why is this considered a collision? - How to avoid?

[rhetteshleman]

I'm 3D adaptive clearing on a mesh and sometimes when the tool get's to the edge of the path it considers it a collision. My machine seems to handle it fine during the actual cut but I'm sure there's a reason fusion is doing this. I've tried changing from silhouette center to outside etc.. but nothing corrects it.  

P.S. Why is Fusion so bad with STL files? Even when faces are reduced to 50k to make it happy my machine (high performance) freezes with 'no responding' errors. I know a bunch on this forum are anti STL in Fusion but it should be able to handle these files better than it does. 

[johnswetz1982]

If you scroll over the red collision lines it tells you what the collision is. In your case "rapid into stock". Your vertical leadins are only ~.020 inches while you have a .250 tool. I always use the tool radius to start with. If I still have collisions then I bump it up the the tool diameter. Same with the horizontal leadins/outs. 

[Anonymous]

For the other part of your post, STL files are PITA to deal with in CAM systems because they are made of enormous number of triangles, a lot to process and reprocess every time change is made to file, it chokes Fusion and computer, often crashing one or the other or both.

In manufacturing where CNC machining prevails, STEP, IGES and DXF files formats are most commonly used.

In all my years in trade I never had STL file supplied by any customer but this trend will probably change for part of the industry implementing 3D printing.

[rhetteshleman]

You're referring to the Horizontal and Vert. lead in/out on the Linking tab? I changed both of those to the tool diameter but It looks like it increased the amount of collisions.  

[johnswetz1982]

The other problem is because of how you have your stock set up. Turn Stock contours Off, Change to silhouette for boundary, with Tool inside boundary, and an additional offset of (leadin+tool diameter) 30mm.

[Anonymous]

All crashes occur on edges of model where tool hits oversize stock, no model to be aware of.

So if you run contour around model to clear the path, all crashes are gone. 

[rhetteshleman]

Thank you both for the excellent responses. I created a contour around the model for the final cutout but didn't think to either make a larger one or use that idea to elimiate the crashes. I had a feeling my stock setup was a bit odd as well. Thank you for two creative solutions.