TECHNOLOGY

HSM (High Speed Machining) is the technology of using higher RPM and higher feed rates to change how chips are formed and provide efficient finishing

HPM (High Performance Machining) is the technology of using high spindle torque and horsepower to remove material 5 to 10 times that of conventional machining and still have high rpm and machine dynamics for finishing.

Hard die milling is the machining of tool steel in the hardened state. This can be done with both HPM and HSM.

MACHINE

Polymer granite is a polymer-bonded mineral casting technology. It is used as a machine base instead of cast iron to increase rigidity and dampen vibration which affects part surface finish and tool life. It also is more thermally stable then cast iron, increasing part machine tool accuracy. It is sometimes referred to as “polymer concrete”.

Portal construction is a machine design where the spindle carrier is supported on 2 sides and an axis travels under and between these supports. This is much more stable and accurate than other machine designs. It is sometimes known as Bridge style construction.

Automation is a term that is describes the ability for a machine to load and un-load parts automatically. Some milling machines offer built in pallet changers.

SPINDLE

Vector Controlled spindles run on a closed loop, where their exact angular position and speed is always controlled. Vector spindles maintain constant speed, no matter what the load is, high torque at a low speed allows high material removal rates and fast run-up and slow-down times thanks to instantaneous control system response. They also have the ability to do rigid tapping.

HSK (Hohler Schale Kegelzapfen or Hollow Shaft Taper) is the taper designation that is used as a better performing alternative to CAT or ISO tapers. Due to its hollow short taper design it has significantly more stiffness than other tapers. It is also more accurate due to the positive face to face contact, not relying on a taper for axial location. Since it is gripped internally, it is also better suited to high spindles speeds, where centrifugal force only adds to the clamping power.

TSC (Through the Spindle Coolant) allows a flow of coolant directly through either the cutting tool or the tool holder. This is common in deep hole drilling or other applications where chip removal becomes a problem.

FIVE AXIS

Positional five axis is essentially the ability to position a part at a specified angle and mill in three axis, with the fourth and fifth axis stationary. Also known as 3+2 machining, it is a very common method for parts that cannot be finished in one set-up.

Simultaneous five axis is the ability to machine with all axes at the same time. This is typically done for parts such as impellers, where there is no alternative method for machining. This method requires a control which can handle constant kinematics calculation as well as normal axis movement processing.

Direct drive rotary tables use torque motors that are directly mounted, so that there is no performance loss due power transmission. Higher overall rotational speed is achieved, and HSM in five axis is now possible.

CONTROL SOFTWARE

Thermal control is important due to the amount of heat generated by high power or high speed spindles.  Thermal expansion needs to be compensated through software. Look for software that maps how the machine grows and contracts through the heat range and compensates accordingly. Some even allow the user to re-establish machine kinematics for the center of the rotaries and can be used in-process to ensure machine accuracy in 5 axis cutting.

Vibration control allows the operator to view the amount of vibration at the lower bearing of the spindle. This is done with the use of an accelerometer mounted at that location. Vibrations in a spindle can be due to a number of reasons, including out of balance tooling or poor cutting conditions. Vibration control should be synchronized with the spindle warranty. It is also possible to track vibration levels and write them to a file, recording data such as program, line number, feed rate, RPM and tool number at each reading.

Remote alert systems give the machine the ability to inform a user or multiple users via a text message. Some are fully customizable, allowing certain message levels to be sent to specific personal.

Spindle Protection compares current spindle condition to original data. It is used to ensure that the spindle is running at optimum levels. Wear, age-related damage and overloading are the main reasons for spindle failure. Insufficient bearing lubrication or poor cooling accelerate these symptoms of fatigue. Depending upon the event, either a warning or an error message with a stop in production is triggered.