Understanding Fadal Resolvers and Encoders for CNC Machines

When working with CNC machines, understanding the difference between resolvers and encoders, as well as knowing what to buy for your specific setup, is critical. Both resolvers and encoders serve the purpose of providing position and velocity feedback for servo motors, but the way they achieve this is vastly different. This distinction plays a key role when deciding on replacement parts or testing whether a device is functioning properly.

Fadal Resolvers: Analog Feedback for Servo Motors

Fadal Resolvers are analog devices that you will find on all Fadal DC servo motors. They provide feedback based on the motor's rotation using magnetism. Specifically, as the shaft rotates, the rotor interacts with the armature, generating three sinusoidal waveforms, each out of phase with the other by a specific number of degrees. These waveforms help determine the motor’s rotational speed and position.

In CNC machines, the Fadal resolver feedback is processed by controller cards located in slots 9, 10, and 11, which then relay the motor speed and position to the machine's processor. The health of a CNC resolver can be tested easily by measuring the voltage output at J1 of the controller card with an AC voltmeter. The expected reading should be around 1.7 VAC, indicating the resolver is in good condition. If this reading is absent, the fadal resolver or its wiring may need to be replaced.

Another way to check the health of a resolver is by spinning the shaft manually. It should rotate smoothly; if it feels gritty, like gravel, the resolver is likely damaged. Furthermore, checking the play of the resolver shaft is essential. There should be minimal side-to-side and in-and-out play. Excessive movement could distort the signals sent to the motor, affecting performance and potentially ruining surface finishes.

ITSCNC offers both new and remanufactured resolvers, identified by part numbers ENC-0008, ENC-0024 and WIR-0066. These resolvers ensure that your Fadal CNC machine maintains its operational integrity, providing reliable analog feedback for servo motor control.

Fadal CNC Encoders: Digital Precision for Modern CNC Machines

Fadal Encoders, in contrast, are digital devices, operating purely with binary signals (ones and zeros). They provide more accurate and durable feedback than resolvers, which is why most modern CNC machines, including Fadal’s vertical machining centers, utilize encoders instead. Fadal Encoders have gradually replaced resolvers in Fadal machines since around 1995, offering greater precision in position and velocity feedback.

Fadal CNC machines employ encoders with two main varieties: a 5000-line count encoder and a 4096-line count encoder, which is quadrature (effectively 8192 lines). The 8192-line count encoders are used in motors like ENC-0004, ENC-0007.

However, replacing an encoder is not a simple task. Unlike Fadal resolvers and encoders require precise timing synchronization with the motor’s armature and internal Hall sensors. Without the proper timing, your CNC machine won’t function correctly, and replacing an encoder without professional expertise can render the motor unusable. Few motor repair shops have the equipment or knowledge to replace encoders successfully. To ensure accurate installation and performance, sophisticated electronic testing gear and real-world machine testing are required.

Fortunately, ITSCNC provides replacement encoders, such as the Accucoder 1000-LINE, US Digital's Spindle Motor Encoder Kit, and the Baldor Encoder MTR-0146/0350/0351. For those who may not feel confident in replacing an encoder themselves, ITSCNC offers a service where you can send in your motor for professional encoder replacement and testing on an actual CNC machine.

Choosing the Right Component for Your CNC Machine

When it comes to purchasing replacement parts for your CNC machine, it’s important to understand the specific needs of your setup. Fadal Resolvers offer excellent durability and are ideal for rugged industrial conditions, while encoders provide higher precision and longer-lasting feedback. Both components play a crucial role in the performance of your CNC machine, and knowing which one you need can save you time and money in the long run.

For Fadal CNC resolver options, ITSCNC offers products like the Fadal Spindle Motor Encoder, US Digital Spindle Motor Encoder Kit, and the Fadal Style Resolver Assembly. Additionally, Fadal Resolver and Renbrandt Coupler 1" x 1" x .25" and Glentek Motor Tachometer (GM4020, GM4050, GM6000) ensuring durability and reliable performance.

On the other hand, ITSCNC’s Fadal encoder offerings include advanced products like the Accucoder 1000-LINE and accessories such as the US Digital Encoder Interface (PC4), giving you everything you need for seamless integration and maintenance.

Support Services from ITSCNC

Beyond offering high-quality Fadal Resolvers and Encoders, ITSCNC provides expert support for any issues you may encounter. Whether you're troubleshooting a malfunction or need help with installation, their team is available to assist with your unique CNC setup. With extensive knowledge and a commitment to customer satisfaction, ITSCNC ensures that your Fadal CNC machine performs at its best.

For any further inquiries or assistance, feel free to reach out to ITSCNC’s team of experts via phone or email.