There's a switch that sets half or full current. The silk screening on the back of the driver labels the switch as a mode setting. On documentation, that switch is standstill current half/full. I'm running 2.8A 269oz NEMA 23 motors with the driver. What setting should I use and why?
Re: Question about current setting on M542T Driver
The setting is used to reduce the current supplied to the motor and reduce heating of the motor. On a screw driven machine it takes very little holding torque to prevent the screw from turning and holding the position. On a belt driven, rack, chain, or similar drive machine, the motor torque needs to be higher to prevent back driving the axis.
The way it works is when the drive sees a lack of commanded movement for a certain amount of time it reduces the current going to the stepper motor. This prevents the current from creating excess heat.
Whether to use it or not depends on a few things. First, what type of axis drive it is. If it is screw driven then it takes very little torque to prevent the screw from being back driven. However, if you have a rack and pinion drive for example, back driving the axis has to be almost totally resisted by the stepper itself. For a rack drive I would leave it at full for sure. For the screw drive it is pretty much personal preference.
The other thing that it depends on is how much you worry about heat. This feature is pretty much just to prevent motor heating or drive heating. I personally think people worry too much about the heat of their motors. Most stepper motors are rated for about 100 degrees Celsius case temperatures. Most times when people worry about the heat of their motors they say they are warm to the touch. So what. 100 deg C is freaking hot, as in boiling water hot. Simple thing to do here is check you motor temp with a non-contact thermometer compare to the motor rating. Now the drive is another story. If you are using a drive at its maximum current and voltage ratings, then it is probably a good idea to run half current idle. If you are far enough away from the maximum ratings then make a judgement call.
Question about current setting on M542T Driver
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