Additive Manufacturing

For much of the past couple decades I have worked at employers who had machine shops. I was regularly in those shops making parts for work, or on occasion after hours for myself. All of the little parts I need for the many projects that appear here on Darker View.

Building an Ender 6 3D printer
Building an Ender 6 3D printer

My current employer does not have a machine shop leaving me no way to make parts for telescopes, electronics projects, or even little repairs around the house. Neither do I have space for a machine shop in the house. Fortunately another, more recent solution is inexpensive and quite capable, additive manufacturing.

Continue reading “Additive Manufacturing”

Little Padded Envelopes from China

Hardly a week goes by without some little padded envelopes in my mailbox. 16×2 LCD character displays, 74HCT541 IC’s, 6mm encoders, some 10mm spirit levels, a couple more ESP-01 modules, and that is just this last month. Living on an island in the middle of the Pacific, there is no place I can buy electronic components. I must order everything.

Little Padded Envelopes from China
Little Padded Envelopes from China
Those envelopes often arrive from places like Hong Kong and Shenzen, China. I find them on my desk where Deb just drops the latest little shipment from the other side of the planet.

The surreal part of this is that it is even conceivable that it would be cost effective to buy components from halfway around the globe like this. Not only is it affordable, but it is easy. It is easy to locate the correct components , it is easy to pay for the items, and it is easy to ship the parts across oceans.

Just a few years ago, buying products like this would have indeed been an insurmountable challenge, now it is routine. The internet and electronic storefronts like eBay that make shopping easy.

Electronic payment networks, notably PayPal, that make payment easy. And a global shipping network capable of getting those little padded envelopes to the correct location. For anyone familiar with history these networks are simply stunning in their capability, something inconceivable even a few decades ago.

Some would question the quality of components from China. You do need to be careful, but unlike cheap consumer goods, electronics components are usually quite acceptable in quality. I have had very little trouble ordering from Asia, the items perform as advertised.

I would probably not order from China if building life support equipment. For my little electronics projects the stuff works. Just check the seller’s ratings and record, then press ‘Buy it Now’.

An Old Project

I have been messing about with electronic circuitry for almost four decades. I recently came across an early example of my work. The device is a digital event counter built around classic 74xx series logic. A chain of 74190 decade counters feed a set of 7447 decoder drivers and seven segment LED displays. A plastic project case with switches and connectors reminds me I have been building little devices for a very long time.

A Digital Event Counter
A digital event counter built when I was fifteen years old.
In some ways the unit is very similar to one of my more recent builds. Perfboard and point-to-point wiring are still standard construction techniques. The technology may have changed across the years, becoming far more complex, but some parts have remained the same.

Continue reading “An Old Project”

To Build a Clock

As I teenager I taught myself digital electronics. Working from the classic books of the day, mostly the TTL Cookbook, I built a succession of projects. Among these was my first clock. Unlike other projects, this clock was a kit from Jameco Electronics. It actually had a printed circuit board, a wooden case, and a red acrylic face. Not only did I get to solder a real circuit board for the first time, I learned every gate and flip-flop in the circuit. When I finished I knew how it worked.

A GPS observing clock or a bomb?
I have built a few more clocks over the years, sometimes with classic seven segment LED displays. The latest was a GPS clock built in the 1990’s to provide accurate time on my observing table beside the telescope in the night. To a nerd like me the glowing LED displays are simply cool, something about this red glow contains a quality missing in the slick color LCD display of my modern phone or tablet computer.

On Monday this week a teenage high school student was arrested and interrogated by police for bringing a digital clock of his own construction to school. Like any young budding engineer Ahmed Mohamed wanted to show off his creation. Unfortunately the closed minds of MacArthur High School in Irvine Texas only saw a Muslim student with a possible bomb. It is clear someone has been watching way too much Fox News.

The most poignant part to me is Ahmed being led out of the school in handcuffs wearing a NASA t-shirt. In those photos I saw myself, a nerd in High School, doing the same things, starting on a road that would eventually lead me to an engineering job on the world’s most powerful telescopes.

Digital Clock
A digital clock built by Ahmed Mohamed, photo released by the Irvine Texas police department
Fortunately the nationwide condemnation of the school administration and local police force has been swift and unforgiving. Social media has seized on this incident, the school’s Facebook page roiling with sharp criticism. Nationwide press articles have been equally unforgiving. Tech industry celebrities like Facebook’s Mark Zuckerberg have shown their support. Ahmed has even received a tweet and an invitation from the president…

Cool clock, Ahmed. Want to bring it to the White House? We should inspire more kids like you to like science. It’s what makes America great. – Tweet by President Barack Obama

It is gratifying to see that the message of many of these comments is that a young person building an electronic project is something to be celebrated, not feared. We should be encouraging students to experiment, to build, to learn. True engineers start this way, exploring technology for themselves, the experience gained can not be taught in a classroom. In my career I have met and worked closely with dozens of engineers, I can tell which ones were tinkerers and makers before they started college, who build and create for the sheer joy of it.

Ahmed is not sure if he will return to school immediately and the family is consulting with attorneys. Police are currently holding the clock as evidence. Thirty years later I still have my first clock.