Shell function that leaves a radius- no more adding fillets or crazy holes left!

[Bruce]

Ok,

 This concerns the behaviour of the Shell feature within Fusion 360. Its biased towards the limitations of CNC milling..

 Below is a before and after of a 2mm shell application:

i would like the shell tool variant to be able to Shell a face while:

1 -"leaving" a fillet of a predetermined radius on specified edges..

2- not undercut unless permitted

3- not leave crazy voids/thin/impossible to machine holes.

I don't know about other designers/machinists, but i tend to use the shell function a lot to lighten the part.

When modelling in fusion and using shelling, i always find myself adding in fillets afterwards.

Imagine real CNC machining. What material in the form of fillets are actually left when pocket mill/ shelling say a cavity with a 10mm ball end mill?.

Many (most) times I don't machine out those R5 fillets, it takes time, tool changes, very little weight loss. Plus they help eliminate stress/fracture points/risers  - let the CAD package capability reflect that reality. My designs are manufactured in-house. Currently i have a small, manual tool change, 3 axis machine - i dont design what i cannot machine.

To achieve this, it would (or could) behave just like a 2.5, 3, 4 or 5 axis machine can.

You would have to specify a "behaviour" in options:

1- "flat end mill mode - only leaves a fillet in the Z plane?

2 - ball end mill - leaves a fillet always, on all edges (but no undercuts if limited to 3 axis behaviour?)

3 - bull nose mill - leaves a fillet too, but a different size in the Z axis.

4- weird hybrid mode for 4 axis/5 axis... enabling undercutting and other headaches.

 When you would specify tool/fillet diameters:

1- it determines the diameter of fillets left

2- it prevent unachievable machining features such as those seen  above - like shelling deep into pointed corners of much less than 90 degrees etc.

If the tool sizes are specified then tool cant pass down these pointless paths.

A "crevass" or pointless shell area elimination/option:

to prevent the shelling option taking it too far, by specifying a minimum shelling area or volume. For example it could stop shelling machining between an array of holes? (the tool radius parameter could prevent this happing too).

i hope this makes some sense. I feel it would be a nice feature and reflect how we design and machine in the real world.

Bruce.