Toward 3D printed Circuit Boards

I have thought up three or four methods for making circuit boards with 3D printers, each with it's particular advantages and disadvantages. The one I will describe here is my chosen method, one that might be called the Guided Wire method. See the images below for reference.

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in the first image we see the method of guiding the wires, one of creating a round trough with a smaller channel above it. The channel is just wide enough to accept the wire, and the wire once forced into the trough with your fingernail or other appropriate tool resides in the cylindrical region below the surface. The second image shows the attempts that I made in doing this. I found that a multiplier of 2.75 times the radius of the wire works best for ABS on my ROBO3D printer's glass bed. Note that the diameter of 22 gauge wire is 0.644mm. In the third photo we see the "breadcrumbs" that I posted to Thingiverse a while back, basically 3D printed perfboard.

Now that I have wires (with some labor involved) and parts holders (perf board or part footprint), I'll need to make an example for soldering. Then after that some trace crossings perhaps and that will be all we need for a 3D printed circuit board!

Les

Here are the results in attempting to add a chip:

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Note that the photo on the right shows the pins soldered to the wires. It's a bit tight but not too tough to solder without touching the plastic substrate, even with my shaky 47 year old ex-alcoholic hands I can do it so you can too (most can). I found the scale zoom of 2.75 to be too large, i will try 2.25 next.

Les

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OK so I'm happy with the notion that I can now make circuit boards, having tested the most basic features and imagined the practicality of others (like crossover wires and multiple layers, 3dism, etc). Next Up I'd like to make a demonstration project that illustrates 3d circuitry in action, preferably with some actual 3D involved rather than just flat circuit boards. To that end I have decided to reach into my bag of tricks and pull out: "Electronic Music Circuits!".

As it turns out I have somewhat of a hobbyist background in electronic music circuitry, both in software and in hardware development. One circuit I've been really wanting to build someday is a one-chip-wonder, where you get whatever krazy sounds (and they may be harsh) from a single chip. That chip, of my choice is the ATtiny85, a miniature Arduino-compatible beauty that sells in quanity one for only $2.00 at Jameco Electronics (www.jameco.com). Jameco also sells everything else I need for this little gem so it's a one stop shopping experience which saves on shipping.

Anyway back to 3D-ism and wouldn't it be nice if i could make a hand-mounted sort of a curved band that fits in the palm snugly and holds all the circuitry on the periphery? That way the instrument could be operated with one hand and i could use the other hand for another of it's kind and do performance art at amateur music festivals such as the electro-music festival which I attended in 2009. OK, TMI but you get the idea, the author is going to make a music box thingie all three-dee-ified on a form that fits his hand.

Now to the photos. Form follows function and the main function here is to fit the hand so I thought I'd take advantage of the rapid prototyping nature of 3D printing by printing up a hand band of sorts. Well as it turns out I got it sized wrong at about 70% of the full size needed for my mighty meat hooks of a pair of hands! Rather than resize and print again, I took this proto and marked it up to approximately designate where the circuitry is to go. Next I'll go back to CAD (in OpenSCAD) and put in approximations of the circuitry but without the wire containment channels (that's a lot of work that is to be done later). As a matter of fact, I'm off to go do that right now so pardon me for making my escape right now!

Les

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It was a two and a half hour print, but worth the time as the photo shows, a perfect fit to my hands. I can mount potentiometers and switches and maybe CAD up a battery holder and some circuit sections all built in at various locations that make sense on the structure. The freedom to morph circuitry with shape and form of the device, to use thru-hole parts mixed with solder tab parts, and to morph or grow some parts into the structure itself is what 3D printing is all about! Now to think of what to buy and where to mount it and how to get good sound from it. I think delay lines are in order and perhaps a few ATtiny85's not just one, well we shall see as we say right?

Les

I think I understand what you are doing, but not having seen the layout of the circuit you are making, it is a bit hard to get up to speed.

Would you have a look at this simple circuit, http://homebrewedrobotics.blogspot.c...e-circuit.html , and see if you can print the circuit board? (The circuit is just one I grabbed at random following a Google search for PCBs.)

Old Man Emu

Yes, Old Man Emu, I understand after seeing your circuit that it will be much clearer to the readers what this technique is and is not capable of doing if I first create your proposed circuit, then make the kooky sproingy artistically inspired thing I am planning to make. I will begin work on your proposed circuit immediately.

Les

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Here is the layout after a fast effort of 3 hours of CAD in OpenSCAD. I'm printing it now...

It should be possible to use the gerber to gcode utility for PCBs. That's what I use for my PCB mill, not sure how you would change it to an extraction gcode rather than a cut gcode though. Maybe Skienforge can do it.

That's an astute observation, Mjolinor, I wasn't even aware that a gerber to gcode utility existed. That would be just the thing for this. As I have it now, I used basic trigonometry and pythagoras' theorem to make it so wires can be specified as grid coordinates [x, y] at begin and end. Same for placement of electronic parts, which also take a rotation, pin count, and spacing parameter. Here is the result:

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I was also thinking that for the most part, assuming modern high impedance electronics it should be possible to use graphite powder and PVA to paint it then sand off back to the plastic. I have no idea how high the resistance of the tracks would be but I reckon for the most part with CMOS stuff it should be fine with the exception of power rails which you would perhaps have to lay with copper.

I have a strange mind. :)

Mjolinor, the stranger the better - to a point. I like your approach. Here is my progress so far:
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I got that far, to my first wire "Tee" when I realized that the wire Tees need special attention. It may just be a pad plus a wiring method and definitely some solder at each Tee. I will put on my giant zappy electrified thinking cap tonight and play around with some possible solutions here. I can't believe that a little cramped wiring is a deal breaker here. Maybe the wire is too thick, maybe i should get out the magnet wire... we shall see.

Les

Lester,
Great work, but could you put on your glasses when you take the photos? They are out of focus. Maybe you could use your camera's Macro setting.

Keep going.

Old Man Emu

hehe, glasses eh? I think I am holding the phone too close to the object, i'll back away a bit. Had to take a break for sleep and mental rest, will get back on it when batteries are recharged, first thing!

Les

rant on - Having a bad day so cannot make progress. It's my 48th birthday and I'm wishing a lot of things were different than they turned out to be. I never got what I what I wanted out of life and even got beat up so bad so many times for so long that I really don't want anything anymore anyway. All the education, the teaching, the research, the work - it all added up to a big fat zero for me. So much for the American Dream... it's a myth. - rant off

I feel your pain Lester, though it was just recently my 33rd (Nature gave me the present of some kind of horrible flu that has lasted two weeks so far). I think around 2009 I pretty much stopped wanting things out of life. Life isn't some kind of sentient entity that you can ask for things, after all. Make whatever you can make, laugh whenever you can laugh, dream everything you can dream, but plan based on what's real.

It might only seem like it has added up to nothing because it has fallen short of what you had expected. If you look again without expectations, you might find a lot that you had overlooked.

Thank you feign, I am feeling better today. I think by tomorrow I can get back on the project. It's wonderful the kind of people that I meet through special interest forums like this - people who really care and don't mind a rant if it's honest and expressed from the heart. I'm moving from a cold empty prison-like apartment to an assisted living home where I will be able to socialize, make friends, and even teach hobbies like 3D printing and programming and weaving chainmaille and all the other fun stuff I do or have done. Plus there will be physical therapy and dietary attention for health. I'm going to give it my best shot, my all, and really make an effort to maximize the benefit of this opportunity. Then maybe the holidays and birthdays won't be quite so horrible and i might even enjoy them.

Les
p.s. I think i'll get back on this project tomorrow starting with a way to handle the wire tees. Thanks for the patience, readers - a little TMI for you hahah!

Lester,

No matter how bad things seem, or how miserable your life seems, just remember that you've been given the gift of a life, and that is a wonderful thing. Who cares if everything you have touched has turned to crap. At least you had the opportunity to make crap, and tomorrow will give you the chance to make more. Even just sitting on the sidelines and watching the world go by, is an exciting pastime. Humans are such interesting things. You are only 48. I'm 62 and don't have the material things like a fancy house, cars, airplanes etc that some people use as measures of the profit of their education and career.

But I do have a roof over my head; and I don't owe anyone any money. I have a loyal wife; two good kids and a wonderful grandson. I wake up every morning realising that shit might happen, but I can always clean up shit and move on.

Don't let the Black Dog get you. Don't keep things bottled up inside. Express your concerns to a willing ear. An most importantly, rejoice in the gift of Life you have received.

Old Man Emu

Thanks for the insight, old man emu. I'll get back to this circuit board project soon, however I have been distracted by another project. I'm making a forearm-mounted rocket launcher out of 3d printed parts - fun! I tell people I'm 48 going on 11 and this is my second childhood, so given a choice between boring circuit boards and awesome personal rocket launchers, well, it's an easy choice. I was actually giggling to myself out loud all last night about this. Here are two photos, one of some rocket shaped storage containers from Thingiverse after which I will model my rockets, and the other is an assembly drawing of the launcher arm attachment hardware. Too cool!

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The rocket project has led to some interest at the local makerspace for a rocket competition, who's 3d printed rocket can go highest, farthest, etc. It has led to some crazy ideas including the self-igniting throwable rocket and the guys at the space even built a rocket stability tester. Zero progress on the circuit boards, sorry to say. I have moved into an assisted living facility where I enjoy interacting with the residents who I meet. I am going to teach 3D printing there.

Les

p.s. I'm finding the human interaction to be very healthy.

Les

Oh yes, one more thing - I made a mistake and created a print of two objects with the second object elevated about 9mm above the build plate. What the printer did was it did not draw a skirt for the elevated object, but when it got to the object's base height, it went over to where the object existed on the bed and deposited some filament which of course came out in a sproingy coil because there was nothing to support it. This leads me to believe that a multi-filament print can be accomplished within certain design constraints.

Les

Quote:

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Originally Posted by LesterCHall

I have thought up three or four methods for making circuit boards with 3D printers

Les

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Hey have you looked at these methods. most require some hardware modifications and 4/5 are for 2d circuits

1. Solder extruder for reprap printer http://youtu.be/Wnu4lmOnX00
2. Laser circuit etching with a reprap http://youtu.be/Chq6TcTeDJc
3. etch resist sharpie attatched to reprap http://youtu.be/QmgCw6b3d3Q
4. turning a 3d printer into a pcb CNC miller. (could be done with a reprap) http://youtu.be/AorVxw305DA
5. conductive ABS filament ( it has some resistance) http://youtu.be/Z8uWpXMxMi8

Hi avocadobaby, my apologies for taking so long to get back to you. I am familiar with or have at least imagined 3, 4 and 5. 1 and 2 are new to me. i'll tell you my current approach in my next post, at this point I'd just like to say that it will take experimentation in all of these and more approaches before we discover what is truly practical for this application.

Les

I'm not sure where I left off on this, just thought I'd mention where I'm at now on both an emotional and a 3D printing of circuit boards perspective.

I have moved into an assisted living facility and I love it! There have been some adjustments and some conflict, but we appear to have resolved all issues. I get exercise walking to the dining room and playing Pop Flux (written by Anonymous, excellent Wii-like free game for iPhone) which has helped the biological machine to function much better lol. Plus I'm making friends, having a good time, and of course 3D printing up a storm. i only wish the printer were faster so I could print more. Anyway, thanks to those who offered perspective, I do appreciate that you care enough about someone you don't even know to be so encouraging.

On the circuit board frontier, I am currently planning to use the Tinnit / CopperFill approach that I thought up (probably among others). Tinnit is a product that tin plates copper chemically - not electrochemically, just chemically. You buy two small bags of white crystals which look identical but are really different chemicals, you put them in the right amount of warm water and stir, then immerse your circuit board in the solution and watch as the copper receives a tin plated coating like magic.

So the approach is to get some CopperFill, print a PCB on PLA with the CopperFill as traces, lightly sand the traces with automotive sandpaper to expose the copper dust / particles, then immerse in Tinnit solution. I read that Tinning coats the copper with a 10 micron thick layer, and we print in 100 micron layers in which I guesstimate there are far more than 10 particles - so you see the math, we should get a conducting layer atop our traces.

That's the plan anyway, I get paid in six days so I'll order some PLA and some CopperFill, I already have the Tinnit. It's worth a try anyway, especially since this method allows for 3D PCBs...

Les