Workpiece vs Mill Volume

[Inho-_-]

Are there any experts in the CREO NC processing programming function???

No matter how I look at it, I don't know the difference between WORKPIECE and MILL VOLUME, can anyone tell me???

[KenFarley]

I use a workpiece to define the material I'm going to be cutting my part from - a block, a partially completed stage of a part, etc. I use them to define datums for roughing, tooling setups, simulation of material removal, etc. Particularly helpful when re-using an existing part to make a new one. It's an indispensable help when defining roughing cuts, for example.

Mill volumes I don't use much. I've used them to define pockets when I wanted to generate a quick spiral or otherwise optimized milling sequence. I tend to think of it as sort of a "cut only here" type of thing - the machining is restricted to the interior of the mill volume.

[Inho-_-]

Then do you usually use mill window or mill surface???

Why don't you use mill volume well???

[KenFarley · Accepted solution]

I might use a mill surface if I need a surface that extends beyond the reference part, or if I want to only machine a specific region of a part. Otherwise I use the surfaces of the reference part. I don't see the purpose in creating extra surfaces and geometry in the manufacturing module that I have already defined in the parts I'm actually machining.

Most of the parts I'm machining are not simple flat surfaced parts. They have curvature, cylindrical or complex 3D shapes, etc. The types of cuts a volume mill provided me were pretty terrible. Flat single depth passes and such. I tend to do more efficient roughing cuts that follow the contour of the part, minimizing the number of passes and maximizing the depth of cut I can do in each pass. I usually have a specific series of steps I need to do to machine the parts, based on tooling, behavior of the specific material being machined, etc. This can save a lot of time - I once had a complex stainless steel part we were building that took about 120 hours to machine when using typical blocky milling steps. Once I'd worked my way through it, optimizing the roughing cuts, the time was down to 25 hours. Of course, that was a worst case scenario, and the application of a lot of techniques I'd learned since I was a newbie when we did the first pass at the process, but the philosophy has served me well since.

My methods require me to have a good feel for the 3D nature of the machining process, but I like that kind of thing, so it's not a problem.

[Inho-_-]

Thank you for answer.
It is understandable that this function is used to reduce machining time and perform efficient NC machining.

Then, in what cases are Mill window vs Mill Surface vs Mill Volume usually used???

[JB_87049]

A workpiece is the rough part you place in your cnc machine to mill the shape of the reference part from.
The Mill Volume is the volume you allow the milling tool to move in while milling the workpiece.