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  1. #11
    Came across these, are they worth having.
    https://www.cnc4you.co.uk/Stepper-Mo...or-8Nm-Nema-34

  2. #12
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 7 Hours Ago Has been a member for 9-10 years. Has a total post count of 2,096. Received thanks 232 times, giving thanks to others 5 times.
    Closed loop steppers are one possible option, and are a pretty good compromise between the existing standard (open loop) stepper motors, and a proper servo system.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

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  4. #13
    Thanks for the help, got the servos and drivers. Went for uc300 and 3 bobs.
    bm01
    cp0-12v
    kk01

    needed additional inputs for the rotary switch on the back of the turret.
    one question though, why do bobs only come with one relay. I need to be able to reverse the spindle, is it possible to use the relay on one bob for fwd and the relay on the other bob for rev.
    cheers

  5. #14
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 7 Hours Ago Has been a member for 9-10 years. Has a total post count of 2,096. Received thanks 232 times, giving thanks to others 5 times.
    Yes.
    However the exact implementation will depend on how the spindle forward/reverse is controlled.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  6. #15
    Scrub that, forgot I had two vfd's to control. One for the turret and one for the spindle. Both need to reverse. This is going to be fun

  7. #16
    i have come to the difficult bit now, i am looking some help with a macro for a tool change. on the rear of the tool changer there is a rotary switch with 8 positions and another micro switch to tell the machine it has locked.
    i have all the inputs reading on the motion controller.
    when the motor goes fwd it pushes the tool plate out and then starts to rotate it, on reverse it draws the plate back in until the micro switch sees it.
    should add i have no clue about macros.
    cheers

  8. #17
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 7 Hours Ago Has been a member for 9-10 years. Has a total post count of 2,096. Received thanks 232 times, giving thanks to others 5 times.
    What turret is fitted?
    And are you using Mach3 or UCNC?
    .
    If it's a Barfuldi TOE and Mach3, unless the UCNC controller has embedded macros/programs, it won't work. Mach3 macros only have a 10Hz update rate, and 1-200ms is far too slow to manage the turret locking sequence, which requires a maximum of a 30ms delay between detecting the strobe bit and activating the locking pin, and only 50ms to reverse the motor direction.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  9. #18
    I am using mach3 through a uc300.
    the turret doesn't have a locking pin, it meshs into a castle like gear. I can't seem to upload pics for some reason. The motor is controlled by an vfd, which I assume you can control the speed of.
    the rotary switch is adjustable on the back to the turret

  10. #19
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 7 Hours Ago Has been a member for 9-10 years. Has a total post count of 2,096. Received thanks 232 times, giving thanks to others 5 times.
    Sounds like you've got one of Denford's own DM turrets.
    Is it like the diagram in this thread? - http://denfordata.com/bb/viewtopic.php?f=40&t=157
    .
    Having had a quick look at the wiring diagram and the description in that thread, it seems to be a case of rotate turret clockwise until position matches, then immediately reverse the turret, at which point it should lock.
    Depending on how fast the turret spins, you may have a problem, as with the 10Hz macro refresh rate, you have a 100-200ms reaction delay depending on timings. However I can't find any info on the timings required, so it'll have to be a case of try it and see.
    .
    I've not done any Mach3 macro programming for a long time, so I'm hoping somebody will convert the following to the required Mach3 code-
    Code:
    While (TurretPosition <> CommandedPosition)
      ActivateTurretCW
    EndWhile
      DeActivateTurretCW
      (a slight time delay may be needed here?)
      ActivateTurretCCW
    While (TurretNotLocked)
      (Do Nothing)
    EndWhile
    DeActivateTurretCCW
    You'll also want to add safety time outs at various places, as if the turret fails to lock, you don't want it to sit spinning endlessly, until you manually stop it running.
    One option you do have, due to the turret using a VFD, is you could slow down the rotation to give Mach more time to respond.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  11. #20
    yes thats the turret, thanks for that.
    can i make use of the rotary switch on the turret, each contact = a tool. there is also a separate micro switch to tell its locked

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