Page 3 of 3 FirstFirst 123
  1. Did i say i was not happy with the suggestions? No.

    I admitted to a personal fault of not being able to start learning another programming language, i am not 19 after all and it does not get any easier. In the last few months i have started on cnc machining, 3d design, 3d CAM and a few other bits, studying a new language does not grasp my attention at all.

    If that makes it sound like i am ungrateful then i apologise but we all have limitations and i have admitted this one, 10 or 20 years ago i would have jumped on it but they didn't exist then did they. Its got nothing at all to do with "being bothered" as you put it, clearly you have no limitations at all.

  2. #22
    Quote Originally Posted by Davek0974 View Post
    clearly you have no limitations at all.
    Not so, but I have, because I was bothered, put in the effort over the last 2 years or so to learn CAD/CAM/CNC from no level of experience at all.
    Prior to that I have in my professional life learned Allen Bradley Ladder Logic in a weekend because a friend and colleague needed me to, admittedly I was already an experienced Z80 assembler programmer (All Hail Rodney Zacks!) but that had no direct bearing other than logical thinking.
    Get a company in for this one, you are clearly not interested in the logical suggestions given, even though with an Arduino there is obviously something close to a solution available and having it professionally tweaked would probably cost you less than your 3 phase motor, gerabox and VFD (which would not furnish a complete solution),

    - Nick
    If you will not be swayed by logic or experience simply pick the idea you
    like best, but ask yourself why you sought advice in the first place and,
    for a simple life, perhaps consider not doing so in future

  3. #23
    JAZZCNC's Avatar
    Lives in wakefield, United Kingdom. Last Activity: 19 Hours Ago Forum Superstar, has done so much to help others, they deserve a medal. Has been a member for 5-6 years. Has a total post count of 5,860. Received thanks 910 times, giving thanks to others 37 times.
    Nick your being a bit harsh here what's wrong with looking for simpler solutions, which is all daves talking about.?
    Just because some half decent suggestions have been made doesn't mean there isn't better ones out there.

    Dave look at Pokeys 57E. They can be run stand alone controller with it's own PLC ladder logic and have Stepper motors to match.

  4. The Following User Says Thank You to JAZZCNC For This Useful Post:


  5. Looking at the process more today, I think we can simplify by orders of magnitude.

    Steppers stop better than they start, especially with a load on them - I am fairly confident that we can get away with just a ramp up and run signal, no ramp down so its just ramp-up, run, stop. Don't forget - this is not CNC, an accuracy of a few mm's is fine here.

    This means we can possibly look at a simple circuit based on a 555 ic with a few components to give the ramp and adjustable speed, i have seen something like that on the 'net, will try and find it again.

    That, with a suitable drive and PSU will be it, nothing more needed apart from a run / stop trigger.

  6. #25
    Hi Dave

    Before I'd suggest a solution I'd question your requirements.

    You say at the end of your first post:

    Quote Originally Posted by Davek0974 View Post
    User input would just need to be a simple pot for the overall speed - this would set the amount of foil fed in the window provided by the start/stop signals.
    No it wouldn't - well not accurately anyway. Consider your mill for a moment. If you want to cut from x=0mm to x=100mm on your mill at a feed of 10mm/s you wouldn't say cut for 10s at 10mm/s. You'd say cut from x=0 to x=100 at 10. If you did the former, you'd be dissapointed. Why? Because it wouldn't actually get to x=100mm. Why? because it's not ALWAYS moving at 10mm/s because of the accel and decel ramps.

    If you want to feed a specific amount of foil between the start/stop signal then that is what you should be specifying - plus of course a desired feedrate (which will be maintained during the constant speed period between the accel and decel ramps).

  7. #26
    Dave,

    It could be that a DC motor and a 555 timer circuit with a pot to set the time and a button to trigger the process would do the job. Some of the timer circuits on eBay have on board pots, so all you would need then is a trigger and a latching relay. The latch would switch the motor on and after a preset time it all drops out waiting for the next trigger.

    As you say, accuracy to CNC standards is not the issue.

    I use a similar circuit to hold off a pump for 7 seconds, otherwise the relay would be switching the pump on and off all the time as soon as the reservoir fluid level drops below the float switch.

    Cheers,

    Rob
    It takes all sorts to make a world, I am just glad I am not one of them.

  8. Quote Originally Posted by stirling View Post
    Hi Dave

    Before I'd suggest a solution I'd question your requirements.

    You say at the end of your first post:



    No it wouldn't - well not accurately anyway. Consider your mill for a moment. If you want to cut from x=0mm to x=100mm on your mill at a feed of 10mm/s you wouldn't say cut for 10s at 10mm/s. You'd say cut from x=0 to x=100 at 10. If you did the former, you'd be dissapointed. Why? Because it wouldn't actually get to x=100mm. Why? because it's not ALWAYS moving at 10mm/s because of the accel and decel ramps.

    If you want to feed a specific amount of foil between the start/stop signal then that is what you should be specifying - plus of course a desired feedrate (which will be maintained during the constant speed period between the accel and decel ramps).
    Yes but its not that complex - the operator set the machine up, sets the foil feed where he thinks it needs to be, runs a few sheets - not enough? just increase the speed a little, too much? then back it off when running.

    Its a simple process, not CNC. :)

  9. #28
    OK - looks like I posted at the same time as your #24 so I didn't see that accuracy was not important.

    In this case I agree with Rob - a DC motor would be a better fit. A stepper is not appropriate for this. It just introduces unnecessary complexity for no gain.

  10. Hmm, ok maybe :)

    Simple pwm control would work, Will have a look at some motors, will still need a gearbox reduction though i think.

  11. Just wrapping this up, going for a stepper motor at present cheap, cheerful and plenty powerful.

    If anyone is interested in moving a stepper without a PC, take a look at the Leadshine DM805-AI drive, it has a built in oscillator and ramp controls, speed input etc, exactly what the doctor ordered, price was 106 inc Vat.

Page 3 of 3 FirstFirst 123

Similar Threads

  1. Stepper motor I.D anyone?
    By Nthkentman in forum Machine Discussion
    Replies: 2
    Last Post: 11-05-2015, 08:03 AM
  2. Replies: 0
    Last Post: 03-01-2015, 03:40 PM
  3. How do I wire a stepper driver to a stepper motor?
    By swood1 in forum Stepper & Servo Motors
    Replies: 7
    Last Post: 21-09-2014, 05:40 PM
  4. Replies: 1
    Last Post: 16-03-2014, 07:29 PM
  5. Leadshine 4-axis motor motion control cards? Any experience and info?
    By Boyan Silyavski in forum Motor Drivers & Controllers
    Replies: 0
    Last Post: 02-12-2013, 06:43 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •