Page 9 of 14 FirstFirst ... 7891011 ... LastLast
  1. Quote Originally Posted by Ross77 View Post
    @ 40V these things sure go bang.
    They go bang because of excessive current not voltage...usually if upper and lower devices in the bridge are 'on' simultaneously... 40v across .5 ohms = 80A peak, 3200W instantaneously.... your PSU will do that for a few 100uS no problem!

  2. #82
    Opto's if none is found when you fire the circuit up it maybe because they require some voltage
    Cheers, I did check the outputs when the onboard processor was controlling the motors and could see the logic highs and lows on the step and dir. pins, but when I tryed to inject a signal in to it my self nothing happened. I was just wondering if anyone knew if the enable pin can completely switch off the chip? as the board is double sided and very crowded it is difficult to see what is going on. (and after the last one went bang , I'm not keen to randomly test points) I was hoping that the enable switch is also controlled by the processor, which would explain why the motors wont work when I try to control them.

    They go bang because of excessive current not voltage...usually if upper and lower devices in the bridge are 'on' simultaneously... 40v across .5 ohms = 80A peak, 3200W instantaneously.... your PSU will do that for a few 100uS no problem!
    Looks like I must have shorted something whist I was trying to get it to work. Is this driver set up usually Ok?

    P.S if you are throwing them away KIP, my bin has plenty of space

  3. #83
    I have a good arm...although the bin in Devon is a throw too far for me :D
    Fair play, It was worth a try tho eh :naughty: Damm you yorkshiremen....

    Im not one to be beaten so had another crack at the control board. Rewired the inputs to the L297, bypassed the output relays and it worked.............:dance:

    ......Until I turned the Vref pot the wrong way and fryed the output chips AGAIN. So at least I've found something i'm good at. :rofl:

    Question time. If all 3 motors are 2 phase, 8 wire and configured in parallel, then why is one of the motors wired differently at the board plug? surley the phases cant change as the motor wouldnt turn...

    Hope to make some real progress this weekend. so post some more pics soon

  4. #84
    Forgot to ask if anyone knows of a good cuircuit to test stepper drives? I'm looking for an MPG type thingy that dosnt require a pc or mach, but will generate the correct pulse voltages, timings etc for step and direction

    Maybe i should post In the drivers section?

    Cheers

  5. Quote Originally Posted by Ross77 View Post
    Forgot to ask if anyone knows of a good cuircuit to test stepper drives? I'm looking for an MPG type thingy that dosnt require a pc or mach, but will generate the correct pulse voltages, timings etc for step and direction

    Maybe i should post In the drivers section?

    Cheers
    Funny you should say that, i was just thinking along those lines...

    I'll post it up later...

  6. #86
    For a really simple 'get you up & running testing a stepper nice & quick', it's really handy to have one of these in your component tray...

    http://www.datasheetcatalog.org/data...stems/5804.pdf


    They don't make 'em anymore so they're getting a little scarce, but still available here...

    http://www.cricklewoodelectronics.co...0&cat=0&page=1

    Pin 11 is the step input - switch that pin low/high - your steppers move. Job done.

  7. #87
    Quote Originally Posted by Kip View Post
    I have a good arm...although the bin in Devon is a throw too far for me :D
    Tell you what, Nottingham is nearer and I can take them down to Bristol on the 22nd when I go to the show.

    Let's shame the bastard :clap:

    .
    John S -

  8. Quote Originally Posted by Ross77 View Post
    Forgot to ask if anyone knows of a good cuircuit to test stepper drives? I'm looking for an MPG type thingy that dosnt require a pc or mach, but will generate the correct pulse voltages, timings etc for step and direction

    Maybe i should post In the drivers section?

    Cheers
    Ross, are you saying to exercise the stepper drivers directly without a PC, or to drive the motors without a stepper driver?

  9. #89
    Cheers guys.
    For a really simple 'get you up & running testing a stepper nice & quick', it's really handy to have one of these in your component tray...

    http://www.datasheetcatalog.org/data...stems/5804.pdf
    That sounds perfect for testing the motors, I was also after something to control the whole driver/ motor setup without a pc.


    Tell you what, Nottingham is nearer and I can take them down to Bristol on the 22nd when I go to the show.

    Let's shame the bastard
    Good idea, he's not biting yet tho..... maybe have to offer some cash:heehee:
    Is that a CNC/ machinery show?

    Ross, are you saying to exercise the stepper drivers directly without a PC, or to drive the motors without a stepper driver?
    Yes I would like to be able to control the whole driver and motor system without a pc. I was thinking along the lines of a varible pulse generator that could feed each axis as required by using a joystick, (like on a Playstation controller) That way i could control direction with the pad and the speed with a trim pot, If it works i might look at using a ps3 analouge type joystick so the speed it proportional to the stick movement.

    Ive been looking on the the net at 555 timer circuits feeding a schitt trigger, but I'm not skilled enought to design it for the correct voltages and pulse timings:sad:

  10. #90
    Quote Originally Posted by Ross77 View Post

    That sounds perfect for testing the motors, I was also after something to control the whole driver/ motor setup without a pc.
    Oops...that'll be the speed reading. Sorry!


    Quote Originally Posted by Ross77 View Post

    Ive been looking on the the net at 555 timer circuits feeding a schitt trigger, but I'm not skilled enought to design it for the correct voltages and pulse timings:sad:
    you wanna tread carefully there ....you could end up with a stinking mess

Page 9 of 14 FirstFirst ... 7891011 ... LastLast

Similar Threads

  1. FOR SALE: Axminster RF40 mill/drill 3 axis dro, Base and extras
    By komatias in forum Items For Sale
    Replies: 0
    Last Post: 04-08-2013, 10:30 PM
  2. NEW MEMBER: Have Built 2 CNC machines 1 mill/drill conversion and 1 Router/plasma from scratch
    By AGB in forum New Member Introductions
    Replies: 3
    Last Post: 06-02-2013, 03:16 AM
  3. WANTED: Small CNC Drill/Mill
    By Mad Professor in forum Items Wanted
    Replies: 0
    Last Post: 03-09-2010, 01:28 PM
  4. Is it possible to modify a drill to be an end mill?
    By HankMcSpank in forum Tool & Tooling Technology
    Replies: 4
    Last Post: 29-04-2010, 02:51 PM
  5. Drill/Mill Spindle brake (RF30)
    By BillTodd in forum Machine Discussion
    Replies: 12
    Last Post: 04-11-2009, 12:09 AM

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
  •