Spindles are an important component of many machining machines, and properly testing and maintaining CNC spindle motors is critical to ensuring optimal performance and longevity. By regularly testing their operation, potential problems can be identified before they lead to machine failure.
Below are some test items. You can also test the following items to determine how well your spindle is running.
Test speed and rpm
One of the most basic tests is to confirm the spindle speed. If the spindle is running too slowly, you won't get the performance you need, and if it's running too fast, it's prone to unnecessary wear and tear.
Check the vibration
Off-axis rotation can occur when the spindle is not rotating on its intended axis, which can degrade performance and also cause tool chatter, shortening its life. In addition, the spindle may produce small vibrations during the machining of a project, which also need to be taken seriously if the vibrations are too large. You can determine vibration by testing for runout along a cross-section of the shaft or along the entire cylinder.
Evaluate the bearing condition
Damaged or worn spindle bearings can cause vibrations and inaccuracies that can affect milling accuracy. If the bearings are excessively worn, they need to be replaced promptly.
Monitoring of temperature
The spindle rotates at high speeds during a machining project, which generates a lot of heat and causes the spindle temperature to rise. High spindle temperatures can reduce performance and possibly damage the windings. An internal temperature sensor can help you detect the spindle temperature, or if your machine does not have an internal temperature sensor, an external sensor can be installed to do so.
Spindle motors can fail due to problems such as excessive vibration, VFD failures, and shorted windings. Disassembling the motor to check for problems is not an easy task for most people. However, you can use a multimeter to check the spindle motor for problems.
Testing of spindles provides early warning of problems before they occur and identifies the source of the problem, which is important for the high-performance operation of the equipment.