E-Sharp News
March 2024
It is a well-known fact that spindles vary in temperature due to a number of factors. These include:
- The spindle rotational speed
- The load on the grinding spindle at any time
- Conditions of coolant flowing through the spindle
These attributes are mostly out of our control and exist as functions of production and machine setup. They will all contribute to the spindle temperature in some magnitude to produce an effect called spindle growth, the result of which has a direct effect on the final dimensional accuracy of the produced item.
Many current forms of controlling this error exist in the form of measurement and compensation. Devices to assist in this method of controlling spindle growth effects are readily available, (we already use these in our machines) however there are several drawbacks such as:
- Measurement is typically performed outside the spindle, whereas most of the thermal growth occurs internally;
- Calibration is required;
- Compensation is applied according to the calibrated information and sensor input, not exactly applied according to the real condition of the spindle.
Staying true to ANCA's heritage of innovating practical solutions, our patented MTC technology offers an answer to the challenge of inaccuracies caused by thermal growth.
It’s all in the name: Motor Temperature Control, or MTC.
Using existing hardware coupled with extensive sensor monitoring, MTC can be applied via a user input set point temperature for MTC enabled spindles within the machine. MTC uses clever firmware to increase and maintain this set point temperature of the spindle to a controlled state, within set tolerance levels (±0.5°C). The set temperature will be maintained on the spindle continuously throughout the production cycle regardless of the spindle growth factors we mentioned earlier, thus effectively eliminating production errors caused by thermal growth on the spindle.
Fig1. Past experience has shown that thermal variation in the spindle is one contributor to variation in the tool dimension accuracy. The OD finish operation of endmills is particularly sensitive to this.
A graphical user interface is provided on MTC-enabled machines to give the user control, setting and monitoring capabilities during production.
Fig 2. MTC control and monitoring panel
Furthermore, MTC is available on both grinding spindle and dressing spindles on MTC-enabled machines. This presents further benefits to high precision production environments, with fully controlled and highly accurate dressing cycles, whereby any effects of thermal growth in dressing cycles are also eliminated.
By providing a comprehensive solution to thermal growth-induced inaccuracies, ANCA’s MTC technology ensures precision throughout the production cycle. Leveraging existing hardware and advanced sensor monitoring, MTC maintains precise spindle temperatures within tight tolerances, mitigating the impact of thermal expansion on dimensional accuracy. With its user-friendly interface and applicability to both grinding and dressing spindles, MTC empowers high-precision manufacturing environments to achieve superior results with consistency and reliability.
21 February 2024