Don't understad the current rating of the TMC2660 and DuetWiFi



  • I am not very good at electronics. The data sheet for the RMC2660 states that the drive Capability is 4A MOTOR current (first page under Features and Benefits). In chapter 15, absolute maximum ratings, it says between 1.8A to 2.8A per COIL.

    The rating for the DuetWiFi is 2.4A for the MOTOR and will be increased to 2.8A.

    Shouldn't the DuetWiFi be able to handle 4A for the MOTOR?

    I am looking on this linear stepper stage :

    https://www.h2wtech.com/product/linear-stepper-stages/LSS-004–004-07-06-XY

    A full step is 250microns.

    Can the DuetWiFi drive it? I am looking for a solution that can do 1g acceleration and 500mm/s. I have contacted the supplier and he says that 4A and 30V is ok. Before I call them I would like to understand what the DuetWiFi can deliver so I can give correct information for the force-speed calculations they will make. I know the max voltage is limited to 25V.

    Thank you in advance!

    PS
    As an alternative I am looking on these servos with integrated drivers in combination with traditional screw solutions
    https://www.teknic.com/model-info/CPM-SDSK-2341P-RLN/
    DS


  • administrators

    Absolute maximum ratings need to be treated with caution, they normally require unrealistic amounts of cooling and are often for short periods only. The ratings on the TMC2660 datasheet have a minimum step rate associated with them.

    The Duet WiFi/Ethernet currently supports 2.4A peak current per phase. The peak total motor current provided by these Duets is 2.4 * sqrt(2) = 3.4A. The linear stepper stage datasheet you linked to gives the rated current as 2.0A, which is probably a per-phase rating with both phases energised. That makes it a good match to the Duet WiFi/Ethernet.



  • Thank you for a swift reply!


Log in to reply