We are a CNC manufacturer with >20 years in the business. Previous products have used brushed motors with fairly simply FET drivers. With this new design we are looking into some radical (for us) control methods. We would like to use bipolar stepper motors vs BLDC because the price/torque figures appear better. The higher torque at the speeds we want to operate lower the carriage mass, increasing feed rate. Our motor guy has proposed an unusual commutation of the 2 phase bipolar stepper motor that has the magnetic field 90 degrees of the electrical waveform. Apparently this FOC/CV control method is not new but finding drivers for it is still difficult.
For awhile, we were trying to make the DRV8829 work. It can handle the commutation scheme but just cannot deliver enough current. So close. Something like that with SPI control (we are low on IO) and 12A switches at 48v would be ideal. At least a model with external fets. We are currently looking at the Allegro A3985.
Anything we may have missed?
Thank you.