One of the parts that came in the other day is a large rectangular block of aluminum with an engraving on one side and an interesting pocket feature on the other.
This single pocket provides a fascinating challenge that you wouldn't think of by looking at it.
The problem with machining this pocket is milling out the radius corners within tolerance while still getting a decent surface finish. Because of the feature's depth and the tight fillets, you can't get too far down into the corners to get a decent finish.
Initially, I programmed this part on the 5-axis with simultaneous movements to clean up those corners and side walls with a ball endmill all in one shot. However, after testing out a few of the 5-axis toolpaths, I couldn't come up with anything that would work very well, and most had multiple weird angles that the machine would have a hard time reaching.
I got on with one of Fusion360's help team to help me figure out the solution to this problem and open my eyes to areas I may have missed. Unfortunately, the solution they gave was very similar to what I had come up with and wasn't ideal but would technically work. The problem is that it focuses more on getting the material removed than simplified axis movements, so it chooses the path of least resistance. Which, in this case, means that it will flip the part upsidedown, attempt to the machine through holes, and other sketchy movements that would crash the machine.
I'm going to have to go back to the drawing board with this one and probably end up doing it all on the 3-axis and taking a ball endmill with small stepdowns along the sidewalls and bottom surface of the pocket.