I am using python 3.6 with pySerial library to connect to the Hyrel System 30M 3D Printer. I am able to read the data from the device but unable to write any commands to it

Here is the code:

    ser = serial.Serial()
    ser.port = 'COM4'
    ser.baudrate = 38400
    out = ser.readline()
    ser.write(b'M106 T14 S30\n') %This is the command to turn on the fan at 30% power

Can somebody suggest me how to write commands to printer through python


2 Answers 2


If the one in your question is your complete code, a possibility is that your computer is just buffering the output for the serial port, withholding it in memory. Try to add


after your last line. This command will... well... flush anything into the buffer through the actual connection.


Sorry for the late answer, but with Repetrel v3 and later, we have the option for you to configure a secondary COM port, and relay G- or M-Code commands from your other source through the Repetrel software to the printer. Please contact us for assistance.

Note: I work for Hyrel 3D.


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