Chamfer and internal radius CAM issue

[Anonymous]

Hi guys, 

I'm a daily Inventor user, Just purchased my first small cnc router and I'm learning the ropes of fusion360.

I've got the part attached below, which I'm just mucking around with to help me learn some of my processes. I'm trying to do my last two machining operations which are the chamfer around the slot, and the small radius scallop on the edge. I've tried a couple of different options but have hit a brick wall. Could anybody please give me some pointers on these two?

Thanks

Matt

[randyT9V9C]

Not sure what radius and chamfer you used so ymmv. See the attached model.

2D chamfer with 1/4" spotting drill. Select the bottom geometry and set for model top. 

2D contour with a 1/4" ball end mill. Select top geometry and use 4 step roughing. When you only want to select a few segments of a geometry use the ALT key.

Hopefully this gets you close to what your looking for. I try to design features for the tools I have on hand so adjust accordingly. 

[Anonymous]

What you've done is a lot simpler than what i was planning. What I'm trying to achieve is using an end mill, in my case a flat mill to do this as best I can. I'm aware how inefficient this is, and will result in a pretty poor finish depending on my stepover, it's more of a learning exercise than anything.

I managed to get this to work on the 45 deg chamfer fine, but when I try and do a similar operation on the filleted area, it keeps trying to do the cut on all my previous pockets too. I tried making these surfaces to avoid and it still didn't work correctly. Any ideas?

Cheers

Matt

[randyT9V9C]

The contour you did works. You might try 3D adaptive clearing also. The adaptive paths work great in slots. Turn off Stock Contours. Select the geometry and choose Tool Inside Boundary. Make sure your helix diameter fits the slot, with the 3/16th end mill I had to use a 2mm helix diameter. 

[Anonymous]

Yeah as per my previous message the chamfer was fine, now it's just the filleted area which I can't get to work via this method, any ideas?

[randyT9V9C · Accepted solution]

Sometimes you need to create a sketch that can act as a boundary/containment area. In the case of your end tab I created a new model sketch, project the contour (appears as purple lines) and then add a few lines to keep it contained. Use 3D adaptive. Deselect Stock Boundary. Select the geometry, choose inside. Set the step height. Set ramp to plunge because your plunging into air anyway. You get the idea.

[Anonymous]

That is perfect! Thanks for the help