It's come to my attention some people aren't using the supplied DB9 mating connectors that come included with the G540 but choosing instead molded DB9 connector / cables much like what's on serial port (COM port) mouse. This presents 3 problems:
1) Undersized wires in the cable. A mouse cable is optimized for flexibility and has to carry next to zero current. The wires within are optimized for that purpose and are very flexible. This emphasis on flexibility renders the wires unable to carry more than 100mA of current before overheating.
2) A mouse DB9 connector is going to have a very low current rating per connector pin, likely to be in the 500mA range. This means the mating connector pins will overheat and may thermally damage the G540 DB9 connectors by annealing the pin sockets.
3) Using a mouse connector / cable means the current set resistor must be placed at the motor end of the cable instead of at the connector. The motor wires will inject noise into the current set resistor wires and this noise will then badly distort the motor winding waveforms. This distortion will cause the motor to run roughly and vibrate.
The 4 Geckodrive supplied mating DB9 connectors have a 5A per pin current rating, most inexpensive DB9 connectors are rated at 3A or less. The supplied connectors are also intended for mounting the current set resistor. This resistor must never be mounted on the motor end of the cable and the G540 was never designed for that being done. 22-gauge wire is recommended for cabling to the motor.
I am interested to know what people use in place of the supplied connectors. No G540 connector / cable vendor has ever submitted their product for our engineering review and I need to know what's being used out there. For instance, it may be necessary to generate a G540 circuit work-around if a lot of people are wiring the current set resistor at the motor end of the cable. I am aware of the convenience this provides if a suitable connector (5A rated) and cable (22-gauge wire or bigger) is used.