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  1. #1
    Quote Originally Posted by ukracer View Post
    Ok thats confirms most of what I understood. Just a bit confused about BOB. https://onedrive.live.com/view.aspx?...PSeNu5hZHOhv5k seems to show a BOB but also a controller conmbined ...
    .....but is that what a BOB is and I have a really cheap one on the chinese CNC box??
    Ok this a common misunderstanding new comers make when they see boards with USB connections.? . . . Clive is correct that's just a BOB which draws it's power from the USB, it doesn't take signals from the USB port only the 5V it needs to run.
    This in it's self is not a good thing either as the USB port is unreliable at provideing a stable power source due to way PC's manage energy so turn off the USB port while in-active and because the board is only drawing power not signals the PC thinks no activity is happening so powers down the USB. If using USB you must change the PC's energy saving mode.
    BOB's and inparticular motion control cards are best powered from a separate power source. Some BOB's can be powered by higher voltage source than 5V and will take there power from the PSU driving the drivers.

    Also not all BOB's require power.? Those that do usually need it to power the opto isolators that protect the input and outputs or for powering on board relays etc.
    Yours will either take it's power from the 24V PSU or not have any at all in which case it's a basic cheap n nasty BOB.!!

    This one you highlighted before is a BOB and motion controller combined. http://www.shop.cncdrive.com/index.php?productID=367
    Last edited by JAZZCNC; 14-10-2014 at 09:50 AM.

  2. #2
    Ok I've just looked at the video to see what the fuss is about. You don't actually need any steppers, drives or even a PC to control this.
    A PLC would do this with no other hardware required other than a PC to program it then it's a stand alone unit.

    The PLC would turn ON/OFF normal motors based on inputs IE button presses or switches and how it's programmed would determine the action it takes regards the time and direction the motors are ON/OFF for. It could be made fully automatic with Switches or semi via buttons. PLC's excel at these tasks.

    It could also be done using relays and controlling via outputs/Inputs from the PC with no steppers or drivers involved. This means you could use the Serial port or the USB has there are no timing issues involved just simple ON/OFF signals. The Control software would then just turn ON/OFF outputs via G-code and using the Dwell and M commands for the time period required. It could also be made to respond to inputs Ie: switches or buttons so it's fully or semi automatic process.
    In affect the PLC is the same with a inbuilt control software which you program directly.

    Also an Arduino would be perfect for doing this simple task but would require a little programing.
    Last edited by JAZZCNC; 14-10-2014 at 10:24 AM.

  3. #3
    Imagine a car engine with the table being a piston. Press a button and a geared motor does one revolution, stopped by a limit switch. This drives a crank that starts at the top, goes down, then back up, taking the table with it by way of a con rod. 'Depth of dip' is controlled by changing the height of the liquid container.
    Semi automatic but cheap and easy.
    Last edited by EddyCurrent; 14-10-2014 at 02:03 PM.
    Spelling mistakes are not intentional, I only seem to see them some time after I've posted

  4. #4
    Quote Originally Posted by EddyCurrent View Post
    Imagine a car engine with the table being a piston. Press a button and a geared motor does one revolution, stopped by a limit switch. This drives a crank that starts at the top, goes down, then back up, taking the table with it by way of a con rod. 'Depth of dip' is controlled by changing the height of the liquid container.
    Semi automatic but cheap and easy.
    Problem I see with that is it has many changes of height for the dip and these floats will require many dips so this will be slow. There needs to be some way to select the height of the dip for each colour also the paint level will be contantly changing as the paint level drops. This will need to be calculated for in the dipping process to be truely automatic process.

  5. #5
    Quote Originally Posted by JAZZCNC View Post
    Problem I see with that is it has many changes of height for the dip and these floats will require many dips so this will be slow. There needs to be some way to select the height of the dip for each colour also the paint level will be contantly changing as the paint level drops. This will need to be calculated for in the dipping process to be truely automatic process.
    I will reply in detail later to the kind suggestions etc but I am trying to get a website running for a guy and they would just chnage the release version just on the day I started...lol

    To explain why I think Jazz is right , whilst I realise a simple system like eddy describes will work, I am looking to future proof etc. "(opening up the potential whilst learning CNC commands at the same time. I had factored in the loss of depth of paint and though I would jog the float tips to the liquid and then program in 2mm for example. Instead of assuming the height of paint would remain constant. I am not going to be producing floats by the thousands but like to keep things automated to a degree..... I am actually using a drill press with manual limit stop to check everything works for now anyway ;)

    Regards Andy T

  6. #6
    Quote Originally Posted by ukracer View Post
    I am not going to be producing floats by the thousands but like to keep things automated to a degree..... I am actually using a drill press with manual limit stop to check everything works for now anyway ;)
    That's what I thought after watching the video, plus all the printing was done by hand anyway, if you are going to watch the machine doing it's stuff then you might as well operate it at the same time.
    As for learning G code with this system, well it doesn't cover many operations.
    Having said that there's nothing wrong with playing about with stuff just for the hell of it.
    Last edited by EddyCurrent; 14-10-2014 at 05:56 PM.
    Spelling mistakes are not intentional, I only seem to see them some time after I've posted

  7. #7
    Quote Originally Posted by EddyCurrent View Post
    That's what I thought after watching the video, plus all the printing was done by hand anyway, if you are going to watch the machine doing it's stuff then you might as well operate it at the same time.
    As for learning G code with this system, well it doesn't cover many operations.
    Having said that there's nothing wrong with playing about with stuff just for the hell of it.

    Yeah I tend to do that . But some times I have a need. I found this. http://youtu.be/WKdyBZvlFXk and this http://youtu.be/SCyGM2Tp37w and while its sort of well "naff", you know what I mean. Its has given me food for thought seeing how slowly it goes when combined with thread rod etc.

    Shame that adafruit he mentions is not in the UK lol Well upon checking it seems they have distributors but it appears they dont sell the hardware...(only a quick look but not a good start! lol)

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