Ever since day one the two Y drive motors having been buzzing at rest like I'm getting a slight voltage to the motors. This is with it at rest with just the machine turned on. What's the cause of that.
You're hearing the winding current being regulated by chopping them at a fixed frequency of around 22KHz. The phase current is modulated using pulse width modulation to support micro-stepping which gives finer resolution, smoother and quieter motion than either half or full step. You'll likely notice the noise will reduce slightly when the motor is positioned at a pole. Think of micro-stepping as two out of phase sinusoidal signals being used to balance the motor shaft between poles by modulating the current into each phase. There are two solutions to reduce the noise. 1. Increase the chopping frequency to take it outside the spectrum of human hearing although the dog may be unhappy. However, this negatively impacts the thermal profile by increasing the temperature of the FETS even if the phase current is low. 2. Reduce the phase current. Machine manufacturers carefully set the phase current and decay profile to give maximum response to overcome the load inertia without creating resonance problems that may lead to pole slippage. To conclude low volume noise is to be expected with stepper motors and isn't a problem. Unlike servo motors, stepper motors create maximum torque at zero velocity. Also remember the machine behaves like a speaker so any noise is amplified through the machine making it sound worse than it really is. You seem to have a 4x4 GS. You'll note if you emptied the water it will sound worse as you've lost the damping effect of the water.
As long as its not an issue or it doesn't effect my cut quality or shorten the life of my machine I'm ok with the slight noise. Thank you
