Features: _x000D_ The expansion board can be used as engraving machine, 3D printer and other drive expansion board. _x000D_ Compatible with GRBL 0.8. Open source firmware running on for that converts G code commands into stepped signals. _x000D_ PWM spindle and direction pins, support 4-axis (X, Y, Z, A - you can copy X, Y, Z or use the pin of D12 and D13 to custom firmware to perform the complete axis 4). _x000D_ Compact structure, stepper motors can be connected to 4 pin connectors or soldered. _x000D_ This is a set of disassembled parts and you need basic soldering techniques to solder them together. _x000D_ _x000D_ _x000D_ Specification: _x000D_ Radiator Size: Approx 8*8mm _x000D_ CNC Expansion Board: _x000D_ Version: V3.0 _x000D_ Voltage: DC 12V-36V (only DRV8825 driver can handle voltages up to 36V, so please consider the power supply voltage) _x000D_ Board Size: Approx. 68 x 53mm / 2.7 x 2.1in _x000D_ A4988 Driver Module: _x000D_ Thermal Shutdown Circuit: Yes _x000D_ Crossover Current Protection: Yes _x000D_ Ground Fault Protection: Yes _x000D_ Short Circuit Protection: Yes _x000D_ Compatible Logic Voltage: 3.3V, 5V _x000D_ Five Modes: full, 1/2, 1/4, 1/8 and 1/16 _x000D_ Size: Approx. 20 x 15mm / 0.8 x 0.6in _x000D_ Mix use the slow current decay model. _x000D_ Internal UVLO and low RDS (on) output. _x000D_ Current decay mode automatically detected/selected. _x000D_ Three-phase rectification, low power consumption. _x000D_ _x000D_ Package List: _x000D_ 1 x CNC V3 Expansion Board _x000D_ 3 x A4988 Driver Module _x000D_ 3 x Radiator