3D-Printed Circuit Boards, For Solder-Free Printable Electronics 106
An anonymous reader writes "Check out the latest success of the OpenSCAD 3d-printed electronics library. To use it, you just need a 3D printer and some conductive thread. OpenSCAD generates a component holder, and conductive thread wraps it all together — no solder, no etching chemicals, no sending out for anything. The instructable takes you through all the steps from schematic to circuit, and includes a more useful example: the fully printed LED flashlight."
It's a shame it's on Instructables... (Score:3, Informative)
It would have been nice to see it without having a full-screen pop-up ad telling me to subscribe to instructables whenever I click on a link.
Conductive thread (Score:4, Informative)
So instead of using that icky earth destroying copper wire, it uses conductive thread. Thread is used by girls making craft projects, what an excellent correlation with the marketing campaign that only women like health and green (seriously, WTF is up with that?). Tada, conductive thread, its great!
Seriously, conductive thread is basically wire wrapping wire with yarn/thread except the connections aren't gas tight so its not as reliable. Wirewrap is great stuff, I built a 8051 based microcontroller in '91 and it still works. Its a 8052AH-BASIC which is basically a preprogrammed 8051, predating the identical concept BASIC-STAMP and more modern ARDUINO by a decade or two. Wire wrap is the opposite of automotive/industrial/aerospace grade as it is completely intolerant of vibration and moisture. Aside from that, its great. I would guess conductive thread would be the same.
Reading the articles, its a cool psuedo Manhattan style construction using little pegs and making the electrical contacts using the psuedo wirewrap thread. I like manhattan construction for experimental stuff... need another connection point? snap off a tiny piece of DS PCB and solder it to the groundplane...
Simplest similar design would be a 3-d printer that can print Kapton filament and regular ole solder paste and a hot air gun. One problem being that a lot of repraps use Kapton for their high temp parts, so you'd need something more exotic. Aside from my having no idea if Kapton is thermo-setting or thermo-plastic and being too lazy to look it up because it ain't happening anytime soon.
If you don't want to use conductive thread, silver bearing epoxy would probably work.
Clunky is right (Score:4, Informative)
Not impressed. I can hand solder a circuit smaller and much cheaper on standard proto board with plated through holes. Done this many times with better results. For circuits I am going to make more than 1 or 2 of just download the free ExpressPCB program and for around $55 you can three boards.
fun for hobbyists (Score:4, Informative)
But it will probably never work for real products. I'd never have the gall to sell an electronic product with connections made of conductive thread. I'd sooner hand-wire it together on perf board.
3D printing works if you need to make one or five objects that don't need to be very robust. But you don't have to get into very high numbers at all before it's cheaper get injection-molded custom parts that are much stronger.
Re:Opening new ways to generate a PCB (Score:2, Informative)
Re:It's a start. A good start. (Score:5, Informative)
The conductive thread has a lot more resistance than real wire-wrap wire (I would have used wire-wrap wire with stripped ends instead of conductive thread for this reason alone). You don't get the gas-tight connections that you get where wire-wrap wire is pulled over the corner of a square post, so there's potential for long-term oxidation and increased resistance (to the point of appearing to be an open circuit at low voltages). Since the "wires" aren't insulated, stretching or sagging from any loss of tension runs the risk of shorting two connections. It's going to be even more prone to loosening from vibration and flexing than wire-wrap.
Re:It's a shame it's on Instructables... (Score:4, Informative)
You can see the thing it's self on Thingiverse [thingiverse.com].
It's a neat idea, kind of fun for first circuits. Some people in the RepRap community have been experimenting with directly printing circuits [reprap.org]. It would be very neat to see that come to fruition.
Re:It's a start. A good start. (Score:3, Informative)
Hey, OP here.
Anyone know anything about how this system ages and/or wears?
This is a very important point of course, because the intention is actually to build something that is production grade (obviously a ways off). But so far I have been actually pretty impressed. The durability of the plastic is extremely impressive (ABS == lego plastic, and my legos have lasted forever..) -- obviously you're mostly wondering about the durability of the circuits. Now I've only built a handful of flashlights which have only been around a few weeks (distributed to a few friends as beta testers), but so far I'm pretty impressed. They could definitely be brighter, and the ergonomics could use some work. But the circuits themselves have held up pretty well.
The conductive thread has a lot more resistance than real wire-wrap wire
But I don't understand why they're using "conductive thread" instead of fine-gauge copper wire
I have tried many types of wires, threads, glues, tapes.. but after a few types of conductive threads, I have found this to have the best properties:
http://members.shaw.ca/ubik/thread/thread.html
At 0.65 ohm / cm, there's not much of a problem with the resistance. It doesn't fray either, but it's also flexible enough to wrap easily, thread holes, tie knots and whatnot (A fine gauge wire would probably work too, but would not function in my current implementation of "slide switch").
so there's potential for long-term oxidation and increased resistance
The thread is coated in silver, so I think it's pretty resistant to that. Definitely something to watch though
Also, because it's unshielded, I anticipate a lot of problems in high frequency applications. This method just seemed like the shortest path to printable electronics (design constraint being, using only one machine and the raw materials). Obviously a lot of work needs to be done to continue to increase the scope of what is "printable".