Welcome to Our Community

Some features disabled for guests. Register Today.

ball screw settings

Discussion in 'CNC Mills/Routers' started by gibson, Sep 2, 2019.

  1. gibson

    gibson Well-Known
    Builder

    Joined:
    Jul 5, 2015
    Messages:
    185
    Likes Received:
    32
    i have ball screw on my machine now but it seems to go very slow this is my ballscrew info Model: SFU1605
    Precision: C7 Grade
    Length: 1200mm
    Diameter: 16mm
    Pitch: 5mm can any one help me out on the settings motors are nema 23
     
  2. David the swarfer

    David the swarfer OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Aug 6, 2013
    Messages:
    3,272
    Likes Received:
    1,833
    the basic setting is:
    stepspermm = (motorsteps * microsteps) / pitch
    assuming 8x microstepping
    (200 * 8) / 5 = 320 steps per mm

    then you need to calibrate HOWTO Calibrate your CNC Machine for MACH3 or GRBL or if you are using OpenbuildSCONTROL then click the 'grbl settings' tab and scroll down to the $100 - $102 settings and use the 'calc steps' buttons.

    you need to calibrate because screws and never exactly the stated pitch unless you pay a kings ransom for them.

    your maximum travel rate will be limited by the maximum rpm of the motors. stepper motors are limited by coil inductance and power supply voltage. higher psu voltage will give you higher speeds but of course your drivers may not handle more than you already have.

    setting max travel rate is a process of try it and see. I usually set the acceleration relatively low, so it takes an inch or two to achieve max speed, then I keep doubling the max speed until it fails to move correctly, doing a relatively long movement for each setting.
    commands like this will move the gantry right 400mm then left again
    G0 X400
    G0 X0

    now go back to the previous working speed and start doubling the acceleration until it fails to move correctly, go back to the one that worked.

    note that this is a balancing act, you can sacrifice some maximum speed for a higher acceleration or you can sacrifice acceleration for higher rapid rate. it depends on what you need the machine to do. lots of small movements benefit from higher acceleration, mostly long between cut movements benefit from higher top speed.
     
  3. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Mar 1, 2017
    Messages:
    13,969
    Likes Received:
    4,099
    That moved to Wizards and Tools on the top menu couple months ago
     
  4. David the swarfer

    David the swarfer OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Aug 6, 2013
    Messages:
    3,272
    Likes Received:
    1,833
    correct! what I pointed out was the basic calculation, but the calibration is on the wizards page
     
  5. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Mar 1, 2017
    Messages:
    13,969
    Likes Received:
    4,099
    Oops my bad! Though the Calculator doesnt have inputs for custom screw pitch, so probably still better to use the Calibration
     
  6. Sarabjit S Mann

    Builder

    Joined:
    Jan 17, 2021
    Messages:
    13
    Likes Received:
    0
    My OpenBuilds 1510 machine is really slow in rapids, how would I make it little faster? Please help.
     
  7. sharmstr

    sharmstr OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Mar 23, 2018
    Messages:
    2,035
    Likes Received:
    1,431
    Check your max rate settings. $110, $111 and $112
    gnea/grbl
     

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