Hi John,

I heard about your thread from a friend and I have not logged in the forum for a long time. As you guys can imagine, I'm drowned in the works of many subjects to improve my machines. I had planned many times to update something here and gathered a lot of materials but just got no time. I reviewed your problems and then write an email to you but you might didn't receive it. We do provide post sale services but I missed your emails to my former temporary email box. Anything please just email to our @skyfirecnc.com email boxes then I or my workmates will see and response.

Anyway, after reviewing your problems, I thought them through and here might some correct answers:

1. about the noise. As you have successfully located the noise source---2 of the stepper drivers---I have 2 most possible reason here

a. We tested the machine for a long time before shipping and I have not seen this noise problem. I think the most possible reason is that we have different power supply voltage. In China, our power voltage normally between 210v-220VAC. But I heard in AU, it will be about 230-240VAC. Then after the transformer, the stepper driver will get about +10% voltage. And this may make the drivers work at the unstable status and then generate some noise and transmit the noise to the controller via power supply circuit.

b. another possible reason is that I simply ordered fake LEADSHINE drivers... and the fake ones don't work stable when the power voltage is higher than in China. I had managed to make the steppers work at a higher end of it's permitted voltage range to gain higher torque and speed. This might not good for your higher local power voltage.

Power voltage difference is the major problem I known from the feedback of initial users. My solution is to add a 240VAC input pin for the transformer. Or switch power supply.

2. about analogue output linear. The JIAMEN motion card has this nature shortcoming. I hope I can explain this clearly. actually, Jiamen card analogue output is not a real analogue signal. It actually outputs the PWM signal but at a high base frequence(1kHz? I can't remember clearly now) The PWM signal will then get "integral" to simulate analogue output. It's a cheap solution and not accurate. I had suggested Jiamen to provide pure analogue output or just real PWM with base frequency 10-100Hz BUT THEY JUST DON'T DO IT..Actually my BLDC driver supports PWM input and even can use RS485 speed control. They can have less than 0.5% speed control tolerance easily. But with Jiamen card, PWM is not an option.

Under this situation, I decided to turn to LINUX CNC or other higher end PC based controllers, or industrial CNC controllers next on my higher end machines. Jiamen card will just be used on lower end solutions. Not only because it doesn't have good spindle speed control features, MACH3 is now not satisfied when we hoping for encoder support, AC servos, ATC, rigid tapping, REALTIME control...etc.

3. about my BLDC driver and motor. Frankly, my BLDC controller is not the best, but can say it reliable after many version developments. And all its parts are real deal for VFD. It's PI control but not PID because it uses AVR IC but not a DSP. AVR is not fast enough to do PID. But PI is still enough for BLDC motor control as an economic solution. My next plan is to update the BLDC motor with encoder and then use STM32 on driver for closed loop control. We can expect the BLDC system will be much more powerful ---especially at low speed end. Current HALL feedback can NOT provide enough PPR to tell the driver how to do at low speed end. Especially when speed control signal is not stable---the BLDC driver will be crazy...

Then the BLDC motor.. It's fantastic but also a big hole for electric engineering. It's much more complex than AC(servo) motors. I suffered a lot to find the best PI for it. Good news is that our current BLDC motor is much much better, and then it's much easier to get it under control. I can't explain too much here because it's a big story to talk.

Then my solution on this subject is: for lower end machines, I have the developed BLDC system. for higher end machines, AC SERVO. I even developed our own AC servo spindle motor and just about to start using it now.

So anyway, I would like to do better and better. Many apologize to the unsatisfied issues accrued. I'm working hard to make machines better and provide better, faster services. I will post my many progresses soon.

Thank you to all of you guys!

Defeng