Welcome to Our Community

Some features disabled for guests. Register Today.

motor synchronization (for newbie)

Discussion in 'Motors' started by JLM, Apr 2, 2020.

  1. JLM

    JLM New
    Builder

    Joined:
    Apr 2, 2020
    Messages:
    3
    Likes Received:
    0
    hi!
    I'm not what I can call an expert when it comes to stepper motors, I know how they work, I know about motors drivers and i played (fixed) some 3D printers....
    but now I want to build my own and I want the frame to be enougth versatile so that I can use use for wood cnc, (maybe some other materials too...), for 3D printing, and maybe for laser wood cuting....

    looking at the comercial frames availables I didn't found ones that fits me....
    my "stepper motors requirements are "
    X axis : 2 steppers + ball screew
    Y axis : 1 stepper + ball screew
    Z axis : 2 sterppers + ball screew
    extruders : 2 extruders (material + support)
    (optionnal : 2 mores extruders for "color printing")
    this makes me 7 steppers motors, 9 at most...

    most 3D printer controller use one driver on X, one on Y and some have dual output for Z, for extruders, they have usually 3 Extruders, which means that one is missing for whole requirements....

    at first I was looking at BIGTREETECH SKR Pro V1.1 Carte de contrôle 32 bit ARM CPU 32bit Mainboard Smoothieboard pour les pièces d'imprimante 3D Reprap Imprimante 3D et fournitures from ectronique on banggood.com

    it has X Y Z0 Z1 E0 E1 E2..... I couldn't find any mother board or "controler" add on, that have enough "driver slots" so I begun to interest me about synchonizing.... so that I can use a single slot (for example X) to drive 2 motors....

    what I understood is that a single controller can drive 2 motors, but it's not recommanded since the power is divided by 2... but maybe if the controller has enougth power this can be a solution????

    other option was to have a "command" replicator and 2 drivers... say the controller use UART for communication, a board with 1 UART input and 2 outputs (and some software to show the readings of controler states as if there was one controller) but I couldn't find any....

    I saw also about H bridge, but if I correctly understood, it's not advised to have a controler driving 2 H bridges...

    what is advised on the forum is to have one controler per stepper... but there is no board with 9 outputs... with the board of the link I can achieve the minimal requirements... but it would be really nice to have the 2 steppers that miss...

    thanks in advance for the help!
     
  2. Gary Caruso

    Gary Caruso OpenBuilds Volunteer
    Staff Member Moderator Builder

    Joined:
    May 19, 2016
    Messages:
    1,184
    Likes Received:
    531
    Hi JLM, you can chain up as many (to a point) of the step and direction wires to multiple drives as you need.
    you can see in this pic of my drive box how YR and YL have signals in parallel.
    Cheers
    Gary
     

    Attached Files:

  3. JLM

    JLM New
    Builder

    Joined:
    Apr 2, 2020
    Messages:
    3
    Likes Received:
    0
    Hi Gary! thanks for the answer!
    that's look interesting your electric connections! it looks as if you have one USART outgoing of the arduino and connected to many controlers! that's exactly what I'm looking for!!!! do you have any schematics ? how do select one driver from another? I means if you share a bus (SPI/USART), there must be some selection mecanism (chip select GPIO, address mapping....)
     
  4. Gary Caruso

    Gary Caruso OpenBuilds Volunteer
    Staff Member Moderator Builder

    Joined:
    May 19, 2016
    Messages:
    1,184
    Likes Received:
    531
    Hi JLM,
    it's not usart, it's GRBL program on the arduino, digital pinout pulses, for step pulses and direction high/low, that's what typical stepper drives understand.
    The red wire is the +5v shared on all the drive input channels and the other wires are XYZ step and direction low.
    Lots of info here at GRBL Wiki and any drive manual, GRBL is not setup for printers unfortunately.
    Cheers
    Gary
     
  5. JLM

    JLM New
    Builder

    Joined:
    Apr 2, 2020
    Messages:
    3
    Likes Received:
    0

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice