Q1:why other supplier's TB6560 driver has 3.5A/3A current,but yours is 2.5A?. 1 x4 Axis TB6560Stepper Motor Driver board 4V Type (High speed Optocoupler). 4 x M4 screw. It is not worthy to save small money to buy a driver board but broken mainboard or lose step and skewing when engraving.
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