Milling part features with thin wall characteristics, while also maintaining dimensional accuracy and straightness, can be difficult at best. Although multiple factors contribute, some key components are discussed below and can help to increase your thin wall milling accuracy.
Use Proper Tooling
Long length tooling with a long length of cut can spell trouble in thin wall milling situations due to deflection, chatter and breakage. It is essential to keep your tool as strong as possible while maintaining the ability to reach to the desired depth. Necked-down tooling provides added tool strength while also helping you to reach greater than 3x Diameter depths.
Axial Depth of Cut (ADOC)
To support the thin wall during the machining process, keep a wide-cross section behind it. We recommend utilizing a “stepped down” approach, which divides the total wall height to manageable depths while working each side of the wall. The Axial Depth of Cut (ADOC) dimension will vary depending on the material (and its hardness) being cut.
Radial Depth of Cut (RDOC)
A progressive Radial Depth Of Cut (RDOC) strategy is also important as the thin wall height is increasing. Reducing tool pressure while support stock is disappearing is equally important to keep the thin wall stable.
- Detail A represents a 5-step progressive radial approach. The number of passes will depend upon your particular application, material hardness and final wall dimensions.
- This approach helps to keep the pressure off the wall as you make your way towards it. Additionally, it is recommended to alternate sides when using this RDOC strategy.
- The final RDOC passes should be very light to keep wall vibration to a minimum while maximizing your part finish.
Additional Thin Wall Milling Accuracy Tips:
- Climb milling will help to keep tool pressure to a minimum.
- Manual vibration dampening and wall stabilization can be achieved by using thermoplastic compounds, or wax, which can be thermally removed.
- The use of ultra-high performance tool paths can optimize tool performance.