[MAS.865](../..) > [Path Planning](..) > Swarf Milling
## Swarf Milling


Various different angle approaches exist.
The extreme cases are illustrated above:
* **End milling** where the contact point is a the center of the tool end
* **Sweep milling** where the contact point is at the periphery of the tool end
* **Flank** (aka **swaft**, **side**, **peripheral**) **milling** where the contact region consists of the whole flank side
### Examples
* [MasterCam Swarf Milling](https://youtu.be/gDHuHBNOnyI?t=208)
* [Swarf 5-axis milling](http://help.autodesk.com/view/fusion360/ENU/?guid=GUID-6953FDC8-4E7F-46D7-BDD5-28BB0D648755)
### Ruled Planning


One standard idea for swarf path planning is to approximate the surface as a [ruled surface](https://en.wikipedia.org/wiki/Ruled_surface).
A surface S is ruled, if for which every surface point P, P is contained by a line that lies on the surface S.
Given a ruled surface, swarf planning then consists of following the side parameterization and changing the orientation correspondingly (provided the tool is long enough and does not collide).
See
* [Ruled Free Forms](https://www.dmg.tuwien.ac.at/geom/ig/publications/oldpub/2012/ruledfreeforms/index.html)
* [Ruled Surfaces for Rationalization and Design in Architecture](https://www.dmg.tuwien.ac.at/geom/ig/publications/oldpub/2010/ruled10/ruled10.html)
as well as the following review: [5-axis flank milling: A state-of-the-art review](https://www.sciencedirect.com/science/article/pii/S0010448512001728)
* [Optimizing tool orientations for 5-axis machining by configuration-space search method](https://www.sciencedirect.com/science/article/pii/S0010448502000775), Computer-Aided Design 2003
* [5-axis machining of sculptured surfaces with a flat-end cutter](https://www.sciencedirect.com/science/article/pii/001044859490040X), Computer-Aided Design 1994
### Piecewise Approximation
* [5-Axis Freeform Surface Milling Using Piecewise Ruled Surface Approximation](http://manufacturingscience.asmedigitalcollection.asme.org/article.aspx?articleid=1433347), Journal of Manufacturing Science and Engineering 1997
* [Making Papercraft Toys from Meshes using Strip-based Approximate Unfolding](http://citeseerx.ist.psu.edu/viewdoc/citations;jsessionid=F0D09A899485D01910779A7B92DD1C0D?doi=10.1.1.112.9289), Siggraph 2004

### Least-Square Surface Approximation
* [Approximation by ruled surfaces](https://www.sciencedirect.com/science/article/pii/S037704279800212X)
* [Flank Milling Surface Design with the Least Square Approach](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.148.6262&rep=rep1&type=pdf)
1. Sample points on surface
2. Approximate points using LS by parameterizing it as a B-spline
### Envelope Fitting

* [Automatic fitting of conical envelopes to free-form surfaces for flank CNC machining](https://www.dmg.tuwien.ac.at/geom/ig/publications/conenv/conenv.pdf), 2017
* [Towards efficient 5-axis flank CNC machining of free-form surfaces via fitting envelopes of surfaces of revolution](https://www.dmg.tuwien.ac.at/geom/ig/publications/2016/flankmachining2016/flankmachining2016.pdf), 2016
### Ruled Surfaces in CAD

* [Computer aided manufacturing technologies for centrifugal compressor impellers](https://www.sciencedirect.com/science/article/pii/S0924013601008287), Journal of Materials Processing Technology 2001