Makerbase MKS SERVO28D/35D Closed Loop Stepper Motor Driver

1. Introduction

The Makerbase MKS SERVO28D and MKS SERVO35D are advanced closed-loop stepper motor drivers designed for precision control in applications such as CNC machines and 3D printers. These drivers support NEMA11 and NEMA14 stepper motors, offering quiet and efficient operation through FOC (Field-Oriented Control) technology. They provide flexible control options including pulse signal, RS485, and CAN communication for position, speed, and torque control.

Figure 1: MKS SERVO28D/35D Closed Loop Stepper Motor Driver

2. Features

Figure 2: Key Features of MKS SERVO28D/35D

• Supports 6 working modes: pulse interface (open loop, closed loop, FOC mode), serial interface (open loop, closed loop, FOC mode).
• Supports CAN/RS485 interface.
• Supports MODBUS-RTU communication protocol.
• Supports curve acceleration and deceleration.
• Supports limit switch to return to zero.
• Supports speed mode, relative position, and absolute position control mode.
• Supports 1-256 arbitrary subdivision, and arbitrary working current setting.
• Maximum input pulse frequency is 160KHz, and maximum speed is 3000RPM.
• Supports multiple motor synchronous working modes.

3. Package Contents

Verify that all items listed below are included in your package. If any items are missing or damaged, please contact your vendor.

Figure 3: Shipping List for MKS SERVO28D/35D Variants

4. Setup and Installation

4.1 Motor Assembly Steps (MKS SERVO28D MT Example)

Figure 4: MKS SERVO28D MT Assembly Steps

1. Install the magnet to the axis of the motor and fix it with glue.
2. Use Phillips pan head screws (M2.5*35) and ABS (6mm) to fix the MKS SERVO28D to the motor, and you need to align the 4P terminal with the direction of the motor wire.
3. Connect the 4 wires of the motor to the 4P screw terminal according to the wire sequence of "green, black, blue, red".
   Tip: Green: A+, Black: A-, Blue: B+, Red: B-.

4.2 Magnet and Magnetic Encoder Distance Requirements

Figure 5: Magnet and Magnetic Encoder Distance Requirements

• Keep the magnet and the encoder chip parallel, with a gap between them of 0.5 and 3.0 mm. The smaller the gap, the better, for optimal results (angle error).
• The center of the magnet should be aligned with the sensing center of the magnetic encoder chip, and the deviation should be within ±0.3mm, otherwise the absolute angle accuracy will be seriously affected.
• Recommended radial magnet Size: Φ6.00mm, height 2.5mm.
• Recommended distance range between magnet and magnetic encoder chip: 0.5mm-3.0mm.
• The deviation range of the alignment between the magnet center and the magnetic encoder chip sensing center is: -0.3mm~0.3mm.

4.3 Wiring Diagrams

General Wiring Tip: In order to reduce bus interference, the host-GND and the motor-GND must be connected together, and RS485/CAN signals are transmitted using shielded twisted pairs.

4.3.1 MKS SERVO28D/35D RS485 Wiring

Figure 6: MKS SERVO28D/35D RS485 Single-Machine and Multi-Machine Wiring

Figure 7: MKS SERVO28D RS485 Interface Wiring Details

4.3.2 MKS SERVO28D/35D CAN Wiring

Figure 8: MKS SERVO28D CAN Single-Machine and Multi-Machine Wiring

Figure 9: MKS SERVO28D CAN Interface Wiring Details

Note: Single slave communication does not need 120 ohm terminal resistor.

5. Operating Instructions

The MKS SERVO28D/35D drivers can be controlled via pulse signals or serial communication (RS485/CAN). For advanced configuration and monitoring, a dedicated Control TOOL software is available.

5.1 Control Tool Software

The Control TOOL software allows users to set system parameters, perform motor control, and monitor motor status. It supports features like factory reset, setting limit switches, and adjusting acceleration parameters.

Figure 10: MKS SERVO D-SERIES Control TOOL Interface

Important: After clicking 'Factory reset', you need to recalibrate again.

The software allows for:

• Setting: Port, Baud rate, Address.
• System Parameters: CtrMode, MStep, En, Dir, AutoSDD, Protect, MPlyer, UartBaud, UartAddr, UartGRP, UartESP.
• Motor Control: Enable/Disable driver board, set limit switch (HomeTrig, HomeSpeed, Limit return to zero, Direct return to zero), adjust acceleration parameters (Start ACC, Stop ACC).
• Motor Status Monitor: Direction, Speed, Acceleration, Status.
• Control Motor Rotation Speed: Forward/Reverse, Speed gear.
• Control Motor Position: Speed gear, Pulses.

For detailed instructions on using the Control TOOL and specific parameter settings, please refer to the official user manual available on GitHub.

6. Maintenance

To ensure optimal performance and longevity of your MKS SERVO28D/35D driver, follow these general maintenance guidelines:

• Cleaning: Keep the driver and motor free from dust and debris. Use a soft, dry cloth for cleaning. Avoid using liquids or solvents.
• Inspection: Periodically check all wiring connections to ensure they are secure. Inspect for any signs of wear, damage, or loose components.
• Environment: Operate the device within its specified environmental conditions (temperature, humidity) to prevent damage.
• Firmware Updates: Check the official Makerbase GitHub repository for any available firmware updates that may improve performance or address issues.

7. Troubleshooting

If you encounter issues with your MKS SERVO28D/35D driver, consider the following general troubleshooting steps:

• Power Check: Ensure the power supply is within the specified voltage range (12V-24V) and provides sufficient current.
• Wiring Verification: Double-check all wiring connections against the diagrams in Section 4.3. Ensure correct polarity and secure connections.
• Communication Issues: If using RS485 or CAN, verify the communication settings (baud rate, address) in the Control TOOL match your host controller. Ensure shielded twisted pairs are used for bus signals.
• Motor Movement: If the motor is not moving or moving erratically, check the magnet and encoder alignment (Section 4.2). Verify motor wire connections (A+, A-, B+, B-).
• Software Settings: Review parameters in the Control TOOL. A factory reset followed by recalibration might resolve configuration issues.
• Overheating: Ensure adequate ventilation around the driver and motor to prevent overheating.

For more specific troubleshooting, refer to the detailed user manual and schematics available on the Makerbase GitHub repository.

8. Specifications

8.1 Product Parameters

Figure 11: Product Parameters

8.2 Interface Specifications

Figure 12: Interface Specifications

8.3 Product Dimensions

8.3.1 MKS SERVO35D Product Size

Figure 13: MKS SERVO35D Product Dimensions

• Overall Length: 31.50mm
• Width: 15.70mm
• Mounting Hole Diameter: 3.3mm (x4)
• Mounting Hole Spacing (width): 10.70mm
• Mounting Hole Spacing (length): 26.00mm
• OLED Connector Length: 16.50mm
• Tolerance: ±0.5mm

8.3.2 MKS SERVO28D Product Size

Figure 14: MKS SERVO28D Product Dimensions

• Overall Length: 28.00mm
• Width: 15.70mm
• Mounting Hole Diameter: 2.70mm (x4)
• Mounting Hole Spacing (width): 10.70mm
• Mounting Hole Spacing (length): 23.00mm
• OLED Connector Length: 16.50mm
• Tolerance: ±0.5mm

9. User Tips

• Always ensure proper grounding for both the host controller and the motor to minimize bus interference.
• When using RS485/CAN, utilize shielded twisted pair cables for signal transmission to maintain signal integrity.
• For optimal angle accuracy, pay close attention to the precise alignment and distance between the motor magnet and the magnetic encoder chip during assembly.
• Before making any changes to the motor or driver configuration, it is recommended to back up your current settings if possible.

10. Warranty and Support

For the latest user manuals, schematics, and additional support resources, please refer to the official Makerbase GitHub repository:

• Main Repository: https://github.com/makerbase-motor/MKS-SERVO42D-57D
• User Manuals: https://github.com/makerbase-motor/MKS-SERVO42D-57D/tree/master/User%20Manual
• Schematics: https://github.com/makerbase-motor/MKS-SERVO42D-57D/tree/master/Hardware

Please consult these resources for detailed technical information and any updates to the product documentation.