Tuesday 9 April 2013

Preparing for small scale production of PCBs

For a number of years, we've been thinking about the future of production and manufacturing. While everyone else seems to be "scaling up" and embracing globalisation, perhaps we're been a little perverse in going the other way. Or maybe we're just "ahead of the curve" and everyone else will be wrestling with the logistics of having stuff made in China, a good three or four weeks away, and shipping stuff half way around the globe, in order to save a few pence-per-unit in production costs.

Here at Nerd Towers we really do believe that the future in manufacturing could (if not should) be through a series of cottage industries. With access to tools like laser cutters, 3d printers, open source electronics, and funding platforms such as indiegogo and Kickstarter, there's no reason why we can't all be making and manufacturing at home. Online retail platforms like eBay, etsy and tindie are perfect for selling products "on demand" - if you're confident you can make a product as it's required, you can start selling without the need to carry lots of stock, or have warehouses full of products tying up all your money. Yet for a lot of physical products, the first thing anyone does when they hit their funding target (on sites like Kickstarter and indiegogo) is to "tool up" and get stuff made in China.

What if we could all become designer, manufacturer, distributor and retailer all in one?
Sure that takes a lot of effort - but running your own business was always going to be that way. The current phenomenon of "drop shipping" - i.e. your customers order from you and you get your supplier to ship directly to them - is just an example of acting as a middle-man, creaming a slice from the profit and letting everyone else do the work. A nice idea - but unsustainable: not everyone can be a middle-man. Someone somewhere has to do some work. So why don't we do that work, bring manufacturing back in-house and provide opportunities for people to work for themselves, from home?

Maybe it's just a pipe dream. But we're determined to give it a try!

Having seen the incredible success of the boardgame Dreadball - something we'd never even heard of until a few weeks ago - we're looking to use a boardgame as a product to try this idea out. In fact, we're building a board for this very board game, with a view to producing manufacturing methods that anyone can use at home to make similar products.

Each board will make use of about 40 "modules", arranged to make a playing surface. If we were building this as a one off, that would mean lots of press-n-peel or maybe even a few hours with some car paint and a laser cutter. But what if we needed to make three or four of these things? What if we needed to manufacture 100+ pcbs?

The easy answer is to draw the layout as gerber files and send off to China, wait four or five weeks and assemble when they arrive. But that goes against the grain of "just in time manufacturing". What if our customers want their gaming boards in under the six weeks it would take? We need to be able to make our own PCBs - quickly and easily (note, cheaply is not the main concern here. Of course price is a consideration, but shouldn't be the driving force).

Now what if we could make large numbers of PCBs quickly? We've already tried CNC milling and drilling PCBs (messy) press-n-peel (expensive and can be sometimes problematic) and laser-etching (slow and inconsistent). One approach we haven't yet looked at - but still used in a large number of semi-automatic manufacturers - is silkscreen printing. Here's a video explaining the whole process:


With screen printing, on a small scale, we could print single- or double-sided boards and modify our CNC drilling machine to drill them afterwards (we'd need to use rivets for through-hole vias to avoid having to go down the whole electro-plating route).

As ever, we're looking for a desktop rather than a workshop-sized solution. So we're after making a small screen printing press, capable of printing up to eurocard size (160mm x 100mm). Our drill already handles eurocard sized boards pretty well, so we'd also need a UV exposure box, suitable for exposing eurocard sized boards.

Of course, in the real world, we'd scale all this up and have A3 or even A2 sized silkscreens, massive sheets of copper board and panellise all our PCB designs. But then we're back with the problems of industrialisation - keeping large stocks of large sheets of copper board is a headache in itself. Storing all the equipment when not in use (we're not looking to build a PCB factory here, more a desktop method of producing lots of PCBs quickly) and having lots of materials hanging around the place is the exact opposite of what we're trying to achieve.

If cottage industry style manufacturing is going to be successful, we need to keep it desktop-sized. After all, it's only once printers become desktop sized that we had the home desktop published revolution in the late 80s, early 90s. It's only since 3d printing has become desktop-sized that we've seen the boom in RepRap and similar 3d printing technologies. Likewise, if home-base manufacturing is to be successful, it needs to be something that can be put got out, used, and put away again - to clear the dining room table in time for tea!



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