mechatronics project

Discussion in 'The Projects Forum' started by afiremain, Oct 31, 2008.

  1. afiremain

    Thread Starter New Member

    Oct 31, 2008
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    I am currently working on a mechatronics project and am competely lost. There is no text book, all I have is the professors notes and schematics, not sure how a lot of stuff works.

    Any way I have to use a stepper motor to lower and raise a sinker to 4" depth, 8", and 12". These are selected based on a binary input of 01, 10, 11 from two switches.

    Now I am not sure at all how to get the stepper motor to rotate 4 turns, to 4 " then switch direction and rotate 4 to return to the initial state. I would assume I need to take the switch input, and compare it to a counter to get it to stop, my main issue is getting it to count down to switch direction.

    Any suggestions on how to change the direction of the stepper motor?

    I am using a 555 frequency input into the binary counter to control speed. These were all specified by the professor. Help me please.
     
  2. mik3

    Senior Member

    Feb 4, 2008
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    Read this here, it will be helpful
     
  3. afiremain

    Thread Starter New Member

    Oct 31, 2008
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    Thanks, I will read that here after class. Question is though how would I do this using J-K flip flops?
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
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    You would need a lot of them to make the counter. If it's a 200 steps/revolution stepper, then you will need to count 2400 steps for the 12" motion.
     
  5. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    If you had a once-around index (opto interrupter, cam and microswitch, whatever), you would need a much smaller counter. It probably wouldn't be as precise as counting motor steps. Do you have any precision requirements?
     
  6. davebee

    Well-Known Member

    Oct 22, 2008
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    I typed "stepper j k flip flop" into Google and found a J-K flip-flop stepper driver circuit pretty easily, which includes a bit to set the motor direction.

    Are there any other parts you're required to use, or anything you're told not to use?

    This would be easy with a microcontroller, if you're allowed to use one and know how to program one.
     
  7. afiremain

    Thread Starter New Member

    Oct 31, 2008
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    I think that I can make a 4 bit counter that takes the frequency, and will simply operate my motor, I can have another counter that counts the 4th step of the motor phase each time it is hit, and then once it hits the 4th step the necessary amount of times have it trip the counter to count down which would reverse the motor, and hopefully find a way to stop at zero, seems like a lot of logic is going to be needed.

    All I have is the 555 frequency, j-k flip flops, transistors, and basic logic gates. Its all I can use.
     
  8. beenthere

    Retired Moderator

    Apr 20, 2004
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    Fight back - set the 555 frequency to .01 Hz and make your instructor watch the 12" motion start to finish. Use reduction gearing.
     
  9. SgtWookie

    Expert

    Jul 17, 2007
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    Ahhh... I'll bet it will have to complete the entire cycle in one class period to get a passing grade.

    Just sayin'...
     
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