Hi again.. I am trying to research basic cnc theory while waiting for my blackbee kit A good few years ago i knew someone with a big professional cnc machine. It wss only 3 axis, but he made incredible organic forms (furniture mostly) by dividing complex 3d objects up into "2.5d" chunks he could do on his machine. Admittedly, iirc the zaxis was very tall. Is this some super trick only he knows how to do or is it a well known process with a name i can read up on? Many thanks!
Not really sure what he was up to, but any 3 axis CNC can do 3D machining - as long as you have the software for it.
So he may have been just splitting a large object into smaller objects to fit under the gantry. Or he may have been slicing the object into layers and cutting those sliced shapes out of flat sheets to build up the object (much like 3D printing). Or he may have been slicing an object into vertical slabs in 2 directions and then joining those cut plates together.
It's almost certainly slicing the model into the thickness of the available (planed) slabs and 3D contour machining with a ball nose end mill, so that they stack together at the end into the desired form. A bit like 3D printing, as David says.
Hi thanks for the replies! I dont think its as simple as slicing into layers, the parts were separated in different angles.. Ive actually found his contact details again, so unless its secret, i hope he can shed some light on the process. Im aware that you can carve in 3d on any 3axis machine, i was more wanti g to know if there was, for example, a tool in fusion360 which could intelligently chop up a 3d form to make it compatible with a 3 axis machine.. Im not explaining very well, take a look at his gallery and youll see what i mean, alhough i have no idea if he has since moved onto a machine with more axes.. For example here you can see clearly an organic chair done in semi flat pieces.. vi — OBJECT
Well, in your example for instance, I would just create a CAD drawing of the whole chair, made up of separate parts including joints etc, then create individual CAM files for machining.. Not really difficult.
Oh, I've seen that kind of work before. It's either CAD modeled if convenient, or sculpted in a sculpting program (or even scanned from another object) and exported as a triangulated mesh which can also be used in CAM. Either way it's then split up according to whatever guidelines the maker is following- fewest pieces, maximum part size, grain direction, symmetry, whatever- and the joints modeled in as well. Then each part is CAM'ed separately and machined. It's pretty simple, just a laborious process upfront. Helpful if you're producing multiples of a design and can justify it. Not sure if it has a specific name, though; it's not particularly unusual to split projects like that into parts regardless of the method of manufacture
I take 3D objects/models and split them down into smaller pieces quite often for cutting. So if it a model you have purchased and only comes to you as an .stl, Microsoft has a built in program in Windows called 3D Builder for editing and cutting into more manageable pieces. I recently took a 3D model I found on Thingiverse (a Tiki) and because it was a little too thick to fit under the X gantry, I scaled the model down in the Z axis a small percentage. But, as said above, if you are modeling it yourself then just model individual components.
