Enlarged board to add a 4thAxis that can clone the X,Y or Z axis. With a 4th option to use pin D12-13 tocontrol it. Added a breakout header for allthe Axis’s Added a communication headerfor UART(Serail) and I2C Added the a connector for anoptional fuse.(Fuse not supplies as it needs to be selected for the currentthat will be used.) Capacitors are mountedhorizontally giving more clearance between them and the stepper drivers. Goodfor ventilation. Added a pull-up resistor on theaxis enable pins. This prevents the pin from being in a floating state Added2 mounting holes This expansion board as a driver expansion board, can be used for engraving machines, 3D printers. It is a total of four slots, can drive four A4988 stepper motor. Each road stepper motors only need two IO ports. In other words, six IO ports can be well managed three stepper motors. It is very convenient to use. Features: · Enlarged board to add a 4th Axis that can clone the X,Y or Z axis. With a 4th option to use pin D12-13 to control it. · Added a breakout header for all the Axis’s · Added a communication header for UART(Serail) and I2C · Added the a connector for an optional fuse.(Fuse not supplies as it needs to be selected for the current that will be used.) · Capacitors are mounted horizontally giving more clearance between them and the stepper drivers. Good for ventilation. · Added a pull-up resistor on the axis enable pins. This prevents the pin from being in a floating state · Added 2 mounting holes Brand other SKU OT776EL17F0IONAFAMZ-61992