I do 4 and 5 axis machining. Nothing like custom designed and machining part for your Telsa coil!
I’m in the process of setting up a desktop 5 axis machine - a PocketNC - to do some projects.
Let me explain things for people listening.
There are two types of 4 and 5 axis machining - indexed and continuous.
Indexed machining has the stock moved in one (4 axis) or two (5 axis) axes to a fixed position. Then 3D machining is done. Many fixed positions (planes) can be set up and used.
The flip jig is a form of 4 axis indexed machining - one angle only (180 degrees).
Continuous machining has everything moving at the same time - 3D plus rotations. CAM software that can do all of calculations - which are extremely complex - is not cheap, is wickedly complex to set up, and takes a huge amount of computation to create the G code.
There are shapes that cannot be machined without continuous machining (e.g. a sphere on stick, all one piece, impellers, turbine blades, nasty curved surfaces of high precision). That said, a HUGE amount of machining is not about continuous work - the indexing replaces a lot of human drudge work setting up and changing jigs and fixtures.
With 4 axis machining, there are some special cases where objects, texts, and shapes can be wrapped onto stock. Conceptually, this really isn’t 4 axis machining… it’s 3 axis machining where one linear axis is replaced with a rotation. This may sound like a let down but let me tell you it isn’t. A huge amount of work can be done this way. In essence, the CNC machine is turned into a very powerful and controllable lathe - and the rotation can be turned on and off and rates adjusted.
@Randy has been thinking on a 4th axis for his Nomad. Something like 4-8 stops for indexed machining.
Fusion 360 supports (4 and 5 axis) indexed machining… but I think one need to be paying for the “Pro” versions to have access to it. Someday, I hope that they have continuous machining.
MeshCAM can perform 4 axis indexed machining. Unfortunately, as far as I know the GRBL boards are not set up for 4 axis work.