Advanced flipping - a.k.a beyond the turners cube

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After playing with the flip jig and watching lots of video’s my brain is full of ideas. The turners cube interests me because its one of few things ive seen that people machine on multiple sides. I was wondering if any of you have done a complex multi-sided design. In my head/imagination I feel like this would work as long as you had your Zero’s perfect. I feel like this would be a way to effectively cut undercuts and kinda fake an extra axis on the machine.

I’ve yet to have the courage to try it but when I’m ready I think ill try something like this pipe. So I guess the point of this thread is have any of you tried it and if so what are the things I should be looking out for?

Octopus Pipe Image

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That pipe is neat, but it’s also hand-carved.

The major issue you are going to run into is holding on to it. Your best bet would be an indexable fourth axis so you can get to all the sides.

You’ll have to leave a stub on each end to hang on to.

You could just build a hand-indexed rotary axis with stops every 90 degrees. That would probably get you what you want.

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Looks like you’re using a brushless RC motor as a spindle

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Could be, it’s not my build, I just pulled the image to show a 4th axis. :slight_smile:

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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.

mark

P.S.

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.

P.P.S

MeshCAM can perform 4 axis indexed machining. Unfortunately, as far as I know the GRBL boards are not set up for 4 axis work.

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