Circuit board creation

  1. ukracer Forum Supporter

    Just a quick question. Whats the cheapest, simplest, quickest, easiest way of producing a circuit board .

    I know I can get some done in China but I would rather do it myself if its not too hard. particularly for the speed part.

    This is what I am trying to create.. https://github.com/gnea/grbl/wiki/Wiring-Limit-Switches and you can see why on that page also.

    Quote
    Capacitors for noise filtering
    Even if you do use NC contacts, you still need those 104 (0.1uF) capacitors, as close to the Arduino as you can place them. You can argue all day that those caps won't make a difference since the caps are shorted out by the switches. The explanation for this phenomenon is quite long but the first power line glitch will convince you otherwise. (Plug in your blender next to the CNC's AC plug and turn it on. Your CNC should still behave normally despite the blender.)

    Side benefit: With NC switches, the connection is broken cleanly when you hit home position, therefore no contact bounce occurs. (Contact bounce occurs only during switch closure, NOT during switch opening.) End quote


    Seems strange they built the board but still suggest adding capacitors to the arduino but coulld they not add them to the Buffer when designing it instead??
     
  2. Seadog

    Seadog Forum Supporter

    Messages:
    6,011
    Location:
    NE London - UK
    What?
     
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  3. ukracer Forum Supporter

    sorry I forgot Cntrl V. lol
     
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  4. msh10 Member

    Messages:
    30
    Shropshire UK
    print it out on to film and use photo etch boards (or thats how we did it a long time ago)
     
  5. mike os

    mike os just a little insane.....

    Messages:
    6,224
    Location:
    North Wales
    Straightforward enough board, all depends how pretty you want it
     
  6. garethp Forum Supporter

    Messages:
    948
    sw scotland
    I've never tried it but I've read articles on using a laser printer to print on paper, then using a clothes iron to transfer the toner onto a prepared board to create a mask before etching it to remove the unwanted copper.

    Ive just googled 'circuit board etching with a laser printer' and it brought up loads of results.
     
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  7. Gazello Member

    Messages:
    69
    Location:
    Bavaria
    Simple perf board , no etching
     
  8. MattH

    MattH Member

    Messages:
    3,777
    Location:
    Bristol
    Over the years I've done manual transfer and etch, laser transfer and etch, Pre-sanitised with UV mask and etch (by far the best method).

    None of these methods comes close to the ease, cost and quality of a professionally made board from China.

    They have all the design and creation software on the webpage, you just knockup a board design and submit it and a week later you have a two sided board with solder mask and silk screen for less than a tenner.

    https://easyeda.com/

    2019-11-18 15.54.04.jpg
     
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  9. sako243

    sako243 Member

    Messages:
    1,031
    Location:
    My mansion in Wales
    Simple version: - it's probably the best location for them.

    Technical version: Reading between the lines here as GRBL is used for controlling CNC machines I'm assuming you are going to be adding these to some form of CNC. There's two seperate issues on the go hear - noise from the switch bouncing and noise from the CNC environment. Switches when they make and break contact bounce horribly - you can eliminate these in both hardware and software, the hardware version is basically a low-pass filter (usually an inline resistor and a capacitor to ground). The software version can take many forms but if you search switch debouncing you'll find lots of examples of different approaches. Where the physical filter is located doesn't really matter it can be next to the switch or it can be close to the microcontroller.

    The second issue you've got is that you are going to be running wires (or in other worse antennae) along the CNC and therefore they're going to pick up a lot of noise from the machine itself (the motors) but if you're doing something like plasma cutting or welding then there'll be even worse noise to contend with as well. This noise tends to be relatively high in voltage but short in time and therefore energy, the way to eliminate this it to add a bank of capacitors near to the microcontroller. How close is "near" - well it's subjective depending on what you're doing, the closer you place them to the microcontroller pins the better because it minimises the chance of it picking up any other noise but if you're Arduino is well away from all the noise and you can guarantee it won't pick up anything in between then you can place the capacitors further away. But why bother?
     
  10. ukracer Forum Supporter

    Might need a better reply later but I am on a roll now..lol Tidying....so for now my logic was (excuse the pun) that if the buffer baord was fitted next to arduino it would be as close as you could get anyway??
     
  11. graffian

    graffian Seer unto the end of his beard

    Messages:
    2,959
    Location:
    gatwick
    I would try a laser print.

    The laser toner hasn't been washed off this one, but the translucent green is where
    the copper has been etched off. You can just make out the traces on the other side.

    matsuura-pcb-02.jpg

    My, still not touched, mill has the limit switches in screened cables, screened bunch of screened pairs cable. And almost every teminal in the machine had a cap on it.
     
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  12. daedalusminos Member

    Messages:
    788
    Location:
    Norwich
    If you're desperate to get something soldered up fast use Veroboard....or plug board for something a little less permanent.

    If you really want a PCB, I'd now always go the cheap Chinese route...it'll be cheaper and quicker in the long run and no chemicals to get rid of.
     
    ukracer likes this.
  13. sako243

    sako243 Member

    Messages:
    1,031
    Location:
    My mansion in Wales
    Their circuit board looks like it's designed to be connected via a cable to the Arduino therefore you are not close (close in electronics terms usually means a few mm).
    cd2eae48-eba7-11e6-9ec0-887fec41f2c7.jpg
    The wires (as I said above) will be antennae picking up noise so definitely not close. If they're short then you might get away with it but you might not (and you won't know from one test, it might take months for an issue to show with potentially catastrophic results).

    I've had to debug issues like this before where it only happens once or twice, seemingly at random, every few months. That is with a test designed to exasperated the issue and let me tell you it's no fun trying to fix issues that random. We even built another £8k circuit board just so we could run the tests on it hoping it would fail while we carried on with other work on other boards.

    This comment from their website is ******** by the way. Anytime you have a mechanical switch you have the potential for contact bounce.
     
    • cd2eae48-eba7-11e6-9ec0-887fec41f2c7.jpg
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