additional stepper drivers for klipper

3 min read 12-01-2025

Klipper, the increasingly popular firmware for 3D printers, offers incredible flexibility and performance. A key component of this performance is the choice and configuration of stepper drivers. While Klipper often comes pre-configured with a selection of drivers, understanding how to add and configure additional stepper drivers opens up a world of possibilities for advanced features and upgrades. This guide explores the process, the benefits, and considerations for expanding your Klipper stepper driver configuration.

Why Add More Stepper Drivers to Klipper?

Adding extra stepper drivers isn't just about increasing the number of motors you can control; it unlocks a range of powerful features:

Multi-tool Support: Want to switch between different print heads or tools on the fly? Additional drivers are essential for controlling the independent movement of each tool's extruder and other components.
Advanced Motion Systems: Certain advanced motion systems, like linear advance or pressure advance, require precise control of multiple motors. Extra drivers provide the necessary hardware to implement these features effectively.
Independent Axis Control: This is invaluable for operations beyond simple 3D printing. Think of advanced features like creating custom macros for complex movements requiring fine-tuned control over individual axes.
Future-Proofing: Adding extra drivers now provides headroom for future upgrades and expansions to your 3D printer's capabilities.

Choosing the Right Stepper Drivers

Selecting the appropriate stepper drivers depends on several factors:

Micro-stepping Resolution: Higher resolution (e.g., 256 microsteps) leads to smoother movements and quieter operation, but it may require more processing power.
Current Capability: Ensure the drivers can provide sufficient current for your motors. Underpowering can lead to missed steps and poor performance; overpowering can damage the drivers or motors.
Driver Type: Popular choices include TMC2208, TMC2209, and A4988 drivers. Each has its own strengths and weaknesses regarding features like stealthChop and spreadCycle. Researching their characteristics is crucial for selecting the best fit for your application.
Interface Compatibility: Verify that your chosen drivers are compatible with your mainboard's interface (e.g., UART, SPI).

Adding and Configuring Additional Stepper Drivers in Klipper

The process involves both hardware and software steps.

1. Hardware Installation:

Connect the Drivers: Carefully connect the new stepper drivers to your mainboard and the motors. Ensure correct wiring to avoid damage. Refer to your mainboard's documentation and the stepper driver's datasheet.
Power Supply: Verify that your power supply can handle the increased current demand from the additional drivers.

2. Software Configuration (Klipper):

Identify the Driver: Determine the type of driver and its configuration options. This information is often found on the driver's datasheet.

Update printer.cfg: You need to modify your printer.cfg file to include the new drivers. This involves adding new [stepper_x], [stepper_y], [stepper_z], or [stepper_e] sections, or more advanced sections for things like additional extruders or other mechanisms.

An example of adding a second extruder (assuming TMC2209 drivers):

[stepper_x]
step_pin: PF1
dir_pin: PG0
enable_pin: !PG1

[stepper_y]
step_pin: PG2
dir_pin: PG3
enable_pin: !PG4

[stepper_z]
step_pin: PE7
dir_pin: PE6
enable_pin: !PC7


[extruder]
step_pin: PC6
dir_pin: PB4
enable_pin: !PF7
...other extruder settings...

[extruder1] ;Second Extruder
step_pin: PA8
dir_pin: PA9
enable_pin: !PA10
...other extruder settings...

[tmc2209 stepper_x]
uart_pin: PE6
tx_pin: PE7
...other TMC2209 settings...

[tmc2209 stepper_y]
uart_pin: PE6
tx_pin: PE7
...other TMC2209 settings...

[tmc2209 stepper_z]
uart_pin: PE6
tx_pin: PE7
...other TMC2209 settings...

[tmc2209 extruder]
uart_pin: PB6
tx_pin: PB7
...other TMC2209 settings...

[tmc2209 extruder1]
uart_pin: PC6
tx_pin: PC7
...other TMC2209 settings...

Restart Klipper: After making changes to printer.cfg, restart Klipper to apply the new configurations.
Test Thoroughly: Test the functionality of your expanded system cautiously, making small adjustments as necessary. Ensure all motors operate correctly and smoothly before undertaking a full print.

Troubleshooting Common Issues

Missed Steps: Check your motor current settings, wiring, and ensure that the drivers are receiving adequate power.
Driver Errors: Consult your driver's datasheet and the Klipper documentation for troubleshooting specific driver errors.
Configuration Errors: Carefully review your printer.cfg file for typos and ensure correct pin assignments.

Adding additional stepper drivers to Klipper significantly enhances the printer's capabilities and opens up possibilities for advanced features. By carefully selecting the drivers, following the proper installation procedures, and thoroughly testing the configuration, you can unlock a new level of control and performance in your 3D printing workflow. Remember to always consult your mainboard's and driver's documentation for specific instructions and configurations.