High speed machining is a proven stipulation characterized by low cutting forces and high metal removal. High Speed Milling is a technique used in the CNC Milling Industry that combines high spindle speeds with increased feed rates. This results in a high chip-forming rate and lower milling forces, producing an improved surface quality and closer tolerances. In high speed milling, the electronics can make all the difference. The right CNC coupled with other elements of the control system can let a slower machine mill a given form faster than a machine with a higher top feed rate.
1. High Speed Uses
High-speed CNC milling is used, for example, to machine the titanium rotors of the first high-pressure compressor stages of the EJ200 engine. High speed CNC milling allows cost-effective milling of the airfoil geometry from the solid. By subsequent finishing operations the planned surface finish is achieved. The CNC milling which caters to high speed must be structured with an axis movement system that is suitable for machining.
2. Axis Movement
The high-speed CNC milling machines required for the process must be fitted with an axis movement system suitable for machining blisks, which should be at least 5 axes simultaneously, depending on the milling task involved and an efficiently high-speed control system.
3. 3D Surfaces
High Speed CNC milling machines working on 3D surfaces in any materials produce a finer surface finish and higher accuracy in less time that the traditional milling machine. Acceleration is the most critical factor that affects the high speed machining. Since one or more axis are always increasing or decreasing velocity in a 3-D cut, ultimate feed rate is directly related to acceleration
4. What Can A High Speed Control Possibly Do?
A CNC milling machine which possesses a higher structural stiffness has a greater potential acceleration rate. Box shaped high speed CNC milling machine, like Bridge and Gantry is the mostly widely used types of High speed CNC milling tools. The overhead type Gantry exudes the highest stiffness, acceleration and accuracy among other high speed CNC milling tools. Due to its scalability, this machine type is available in sizes to match the work piece, from small to large.
In usual terms, it simply gives you the ability to finish one task faster and move along to the next sooner, making work output higher. In drilling and tapping, this can result in faster hole-to-hole times, quicker spindle reversals for tapping, and substantial cycle-time reductions. The most dramatic benefits, though, come in 3D designs machining. Few, drilling and tapping jobs require a million lines of machine codes. In molds, dies, patterns, and prototypes, complex surfaces comprising a million or more line segments are not at all uncommon. Saving just a fraction of a second per move can result in substantial cycle-time improvements.
5. Downsides - When Is Fast Too Fast?
But despite all these benefits, in high milling, the tool path segments can be so short that a machining center moving at a high feed rate can’t accelerate or decelerate fast enough to make direction changes accurately. Corners may be rounded off and the work piece surface may be gouged. Look-ahead is one answer. Look-ahead capability can let the CNC read ahead a certain number of blocks in the program, to anticipate sudden direction changes and slow the feed rate accordingly.
6. Additional Benefits:
- Improved accuracy
- Better fit
- Superior finish
- Better life
- Produce more work in less time
- Improving the accuracy and finish
- Reducing polishing and fitting time
- Tools simply last longer because their chip load is more consistent