The purple boards slotted into the pairs of SIL headers are Pololu Stepper motor drivers. Going this route makes replacing a burnt out chip as easy as plugging in a new module. The terminal block ...

That’s the idea behind [BetaChecker’s] two-axis stepper motor ... through a large number of L293 H-bridge chips and an Arduino Mega. A variety of sleds, each with neodymium magnets in ...