Machining a Solid Disco Ball on a Five-Axis CNC Mill
This fascinating tool, made by Detroit-based precision tool manufacturer Cogsdill, is called a DBFM (Diamond Burnish Face Mill tool).
![](https://s3files.core77.com/blog/images/1307469_81_116727_ZsjponSmM.png)
It mounts into a standard milling arbor, and each of the posts have a spring-loaded diamond insert in the tip. When the tool comes into contact with the metal workpiece, the springs force the diamonds against it, and it then produces a mirror-like finish.
![](https://s3files.core77.com/blog/images/1307468_81_116727_FFPG4oAFS.jpg)
As an example, the top half of the workpiece below shows a merely milled surface, whereas the bottom half has been finished with the DBFM.
![](https://s3files.core77.com/blog/images/1307471_81_116727_X_v0ZzymW.jpg)
![](https://s3files.core77.com/blog/images/1307470_81_116727_iL00km6RN.jpg)
Titans of CNC Machining got their hands on a DBFM, and used it to finish a disco ball that they milled out of a chunk of aluminum: