Distractions in electronics

It’s been a while since I last posted, and there’s been a massive amount of progress to report. I plan to release a series of updates in the coming weeks to recount the work that’s been done. 

Work over the summer took a turn as I attempted to craft electronics for the child printer with the help of its parent. I began initially with plans to make Traumflug’s laudable generation 7 electronics. PCB manufacture would be done through the etch resist method. I quickly realized that PLA plastic was not a suitable substitute for etch resist as it simply could not adhere to the smooth copper plate. With that, I switched to an ink based resist with the usual post-apocalyptic bent. In short, this means I stuck a magic marker on the printer and stood back:

2013-06-16 23.32.46

Not bad, not bad. A few tracks laid were sitting awfully close to one another, but that wasn’t anything that could be fixed with some alcohol and a q-tip.

Next came the etchant.

 2013-06-19 19.48.18

Chemistry in the grim dark future might be a little tricky. The most common etchant used is ferric chloride, but many diy-ers today have used a combination of hydrogen peroxide and muriatic acid. Muriatic acid may be much more accessible without infrastructure since it can be made readily from dissolving chlorine gas in water. Chlorine can be produced easily enough via electrolysis, though handling it safely is, of course, another matter. At first the ease of producing muriatic acids seem to suggest the acid/peroxide approach is preferred in the context of my study, but we also have to consider the other ingredient, Hydrogen peroxide. To me, the production of hydrogen peroxide is prohibitively esoteric. It’s do-able, perhaps, but if you already have muriatic acid, ferric chloride is just a reaction away – a matter of mixing muriatic acid with a source of iron oxide, e.g. rusty nails. It was for this reason that I ultimately went with the ferric chloride method. While it would be an interesting endeavor to make the solution from scratch, I am in no way inclined to mess with chlorine gas, so we’ll settle for a bottle of ferric chloride we get from radio shack, okay?

 

2013-06-19 20.26.56
The resist is washed away with some alcohol
2013-06-19 20.32.23

 

 

 

 

 

and what remains are the circuits…

 

 

 

 

 

2013-08-11 14.54.44 all that’s left is drilling and soldering

 

 

 

 

 

 

aand done.  2013-08-11 14.56.10 

Well, I’m never doing that again. Why, you might ask?

 * chemical etchant is useful for mass production, but it isn’t going to last long if you have to produce your own chemicals. The dangers involved are so prohibitive I would never dare to attempt them in a real post-apocalyptic setting, let alone my current situation where I do it for fun.

 * Drilling through holes in a modest workshop is tedious and inaccurate. Honest, this thing is still lying in my workshop. I still have yet to test it! I don’t even want to bring myself to test it since I know there would have doubtlessly been issues incurred by this step of the process that render my efforts moot and unrecoverable.

Trying to escape the tedium of drilling only makes matters worse. Surface mount technology is an obvious solution to the problem, but then you have to work with scales much smaller than could be afforded by someone in this context.

For heavens sake, just look at it!2013-08-11 14.56.00

 

 

 

 

 

 

 

 

 

So with that, this is one part of my experiment where I have met with disappointment. Trying to manufacture a specialized PCB in a scavenging society is simply not feasible, if at the least not through the chemical etchant method that I attempted. Chemicals are quickly spent and can only be resupplied by methods that have no place in a nonindustrial setting. While it’s still theoretically possible in a post-apocalyptic environment where health and safety standards are relaxed, someone in this environment would be far more ready to etch pcbs by mechanical means, that is, by way of a CNC mill. A CNC mill shares many of the same principles as a 3d printer, and its reasonable to assume anyone capable of using the etch resist method would also have the knowledge needed to create a CNC mill. Once a CNC mill is created there is no need to rely on a dwindling supply of chemicals to manufacture electronics, no need to drill holes by hand, and most important of all, the utility of a CNC mill extends much farther beyond etching printed circuit boards. The experience I’ve accrued in chemical etching has clearly outlined the need for a CNC mill in the future of this project.

Barring the use of CNC mills, the only hope for the future would lie in devices made before the downfall of society – chiefly breadboards, stepper drivers, and DIY microcontrollers like the Arduino. It’s very reasonable to assume progress could be made for a time while these devices remain functional. The fact these devices are so versatile means they are very likely to be found lying around in workshops today, and the same versatility means they can be put to use in any number of ways after the collapse of society. Compare this with the electonics one could scavenge from pcbs: while certain components (e.g. resistors, transistors, capacitors) would be much more readily available than an Arduino board, a certain subset (e.g. integrated circuits) would be much harder to find, and these more likely than not are a sine qua non for technologies such as 3d printing. It’s possible that someone could find an IC that would suit his purpose to some extent, but unless that IC is a break out replacement for what he needs, he will likely have to redesign his entire board around it.

Now, I would go through the exercise of building the electronics through breadboard, but this is something I had already accomplished in order to create the parent printer. In the interest of time, I have gone ahead and procured an Arduino shield for the child, the ever popular RAMPS. Please forgive me if this comes as a cop-out, but as I continue to work on this project I maintain the peripherial goal of upgrading my modest carpenter’s workshop to a reliable maker’s laboratory. 

Clearly, it seems progress is still needed if 3d printing is to ever survive long term in a post-apocalyptic setting. We have certainly demonstrated it can exist for a time, but unless we find a way to manufacture the computers and microcontrollers that drive the 3d printers we will find it increasingly difficult to maintain them. Perhaps one day, 3d printers could be able to print entire circuit boards, components and all. This would require a great deal of progress to be made in the realm of materials science, but were it achievable it would ensure the continued existence of many of the things we come to associate with modern life.

 

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