Pinball still has that bit of magic that makes it stand out from first person shooters or those screen mashers eating up your time on the bus. The secret sauce is that sense of movement and feedback, and the loss of control as the ball makes its way through the play field under the power of gravity. Of course the real problem is finding a pinball machine. Pinbox 3000 is swooping in to fix that in a creative way. It’s a cardboard pinball machine that you build and decorate yourself.
We ran into them at Maker Faire New York over the weekend and the booth was packed with kids and adults all mashing flippers to keep a marble in play. The kit comes as flat-pack cardboard already scored and printed with guides for assembly which takes about an hour.
The design is quite clever, with materials limited to just cardboard, rubber bands, and a few plastic rivets. Both the plunger that launches the pinball and the flippers are surprisingly robust. They stand up to a lot of force and from the models on display it seems the friction points of cardboard-on-cardboard are the issue, rather than mechanisms buckling under the force exerted by the player.
When first assembled the playfield is blank. That didn’t stop the fun for this set of kits stacked back to back for player vs. player action. There’s a hole at the top of playfields which makes this feel a bit like playing Pong in real life. However, where the kit really shines is in customizing your own game. In effect you’re setting up the most creative marble run you can imagine. This task was well demonstrated with cardboard, molded plastic packaging (which is normally landfill) cleverly placed, plus some noisemakers and lighting effects. The company has been working to gather up inspiration and examples for building out the machines. We love the multiple layers of engagement rolled into Pinbox, from building the stock kit, to fleshing out a playfield, and even to adding your own electronics for things like audio effects.
Check out the video below to see the fun being had at the Maker Faire booth.
Serpentine is a gesture sensor that’s the equivalent of a membrane potentiometer, flex and stretch sensor, and more. It’s self-powering and can be used in wearable hacks such as the necklace shown in the banner image though we’re thinking more along the lines of the lanyard for Hackaday conference badges, adding one more level of hackability. It’s a great way to send signals without anyone else knowing you’re doing it and it’s easy to make.
Serpentine is the core of a research project by a group of researchers including [fereshteh] of Georgia Tech, Atlanta. The sensor is a tube made of a silicone rubber and PDMS (a silicone elastomer) core with a copper coil wrapped around it, followed by more of the silicone mix, a coil of silver-coated nylon thread, and a final layer of the silicone mix. Full instructions for making it are on their Hackaday.io page.
There are three general interactions you can have with the tube-shaped sensor: radial, longitudinal, and tangential. Doing various combinations of these three results in a surprising variety of gestures such as tap, press, slide, twist, stretch, bend, and rotate. Those gestures result in signals across the copper and silver-coated nylon electrodes. The signals pass through an amplifier circuit which uses WiFi to send them on to a laptop where signal processing distinguishes between the gestures. It recognizes the different ones with around 90% accuracy. The video below demonstrates the training step followed by testing.
The IBM 1401 is a classic computer which IBM marketed throughout the 1960s, late enough for it to have used transistors rather than vacuum tubes, which is probably a good thing for this story. For small businesses, it was often used as their main data processing machine along with the 1403 printer. For larger businesses with mainframes, the 1401 was used to handle the slower peripherals such as that 1403 printer as well as card readers.
The Computer History Museum in Mountain View, CA has two working 1401s as well as at least one 1403 printer, and recently whenever the printer printed out a line, the computer would report a “print check” error. [Ken Shirriff] was among those who found and fixed the problem and he wrote up a detailed blog entry which takes us from the first test done to narrow down the problem, through IBM’s original logic diagrams, until finally yanking out the suspect board and finding the culprit, a germanium transistor which likely failed due to corrosion and an emitter wire that doesn’t look solidly connected. How do they know that? In the typical [Ken]-and-company style which we love, they opened up the transistor and looked at it under a microscope. We get the feeling that if they could have dug even deeper then they would have.
To say that the Commodore 64 was an important milestone in the history of personal computing is probably a bit of an understatement. For a decent chunk of the 1980s, it was the home computer, with some estimates putting the total number of them sold as high as 17 million. For hackers of a certain age, there’s a fairly good chance that the C64 holds a special spot in their childhood; perhaps even setting them on a trajectory they followed for the rest of their lives.
At the risk of showing his age, [Clicky Steve] writes in to tell us about the important role the C64 played in his childhood. He received it as a gift on his fifth birthday from his parents, and fondly remembers the hours he and his grandfather spent with a mail order book learning how to program it. He credits these memories with getting him interested in technology and electronic music. In an effort to keep himself connected to those early memories, he decided to build a modern keyboard with C64 keycaps.
As you might expect, the process started with [Steve] harvesting the caps from a real Commodore, in fact, the very same computer he received as a child. While the purists might shed a tear that the original machine was sacrificed to build this new keyboard, he does note that his C64 had seen better days.
Of course, you can’t just pull the caps off of C64 and stick them on a modern keyboard. [Steve] found the STLs for a 3D printable C64 to Cherry MX adapter on GitHub, and had 80 of them professionally printed as he doesn’t have access to an SLS printer. He reports the design works well, but that non-destructively removing the adapters from the caps once they are pressed into place probably isn’t going to happen; something to keep in mind for others who might be considering sacrificing their personal C64 for the project.
[Steve] installed the caps on a Preonic mechanical keyboard, which worked out fairly well, though he had to get creative with the layout as the C64 caps didn’t really lend themselves to the keyboard’s ortholinear layout. He does mention that switches a bit heavier than the Cherry MX Whites he selected would probably be ideal, but overall he’s extremely happy with his functional tribute to his grandfather.
When you think of sports, you usually think of something that takes a lot of physical effort. Golf is a bit different. Sure, you can get some walking in if you don’t take a cart. But mostly golfing is about coordination and skill and less about physical exertion. Until you want to practice driving. You hit a bucket of balls and then you have to go walk around and pick them up. Unless you have help, of course. In particular, you can delegate the task to a robot.
The robot that [webzuweb] built looks a little like a plywood robot vacuum. However, instead of suction, it uses some plywood disks to lift the balls and deposit them in a hopper. The electronics consist of an Arduino and an Orange Pi Lite. A GPS tells the robot where it is and it develops a search pattern based on its location.
Although [webzuweb] notes he isn’t done with the project, it looks pretty good. He describes the software, but it doesn’t appear to be posted anywhere. However, he does describe its operation and how it changes mode based on its current state.
We can’t decide if golf is really a sport or more of a game. We were surprised to read that if you carry your own bag and don’t use a cart you can burn about 360 calories an hour which is somehow more than a gymnast burns, which hardly seems possible.
Of course, most people use a cart and a caddy, so they aren’t going to burn those calories. If you are in the market for a cool cart, we liked this one. Or, perhaps you’d like one with more power.
We are spoiled these days because you can shop online and get all manner of inexpensive electronic goodies shipped to your door. This is due to the fantastic electronic fabrication workflow that has grown into a global powerhouse, facilitated by complex yet inexpensive integrated circuits! But it took a few intermediate steps to get here, and one of those is known as a couplate.
When I was a kid, the big deal was to find an old radio in the trash. You could spend a few hours stripping all sorts of parts from the thing and add it to your collection for a future project. Of course, old radios from the 1970s and earlier had a lot of the usual parts we use today, even though many of them were bigger — no surface mount parts yet. Since older radios were the usual find in a dumpster, tubes were common but you could find some transistor radios.
Once in a while something older. There would be a little box with some wires poking hiding in an old radio from the 1940s or 1950s (too early for ICs). In a way, though, these were predecessors to the Integrated Circuit and they went by a few names, depending on who sold them. PEC (Printed Electronic Circuit), a couplate, or a BulPlate, are all names for hardware that was a stepping stone between discrete circuitry and ICs.
Collections of Passive Components
PECs were most common in tube sets and they didn’t have any active circuitry. They sere often set up to handle audio filtering or some other common task using just resistors and capacitors. Companies known for these devices Areovox (PEC), Centralab (couplate), or Sprague (BulPlates). The example shown here, the PC-33 from Centralab, sold for fifty cents and had three terminals
The PC-33 is not terribly impressive, but a PC-151 (see right) had 7 pins and the schematic is quite impressive. The couplate itself only had the bold components, not the tubes and other components showed in gray. That little jewel cost about $1.15. Doesn’t sound like much, but in 1950 terms that was like $12 today. In fact, we found one on eBay for $11.90 so maybe there’s something to that.
Another place you would find these were in TVs where a vertical integrator PEC could help with sweeping the CRT. It was basically three resistors and three capacitors set up to help generate a vertical deflection ramp.
There were a very few PECs made with tubes as active devices. Well, more accurately, with tube sockets. Some 1950 promotional material from Centralab said:
There’s never been an electronic device like Centralab’s Ampec. It is one compact unit permanently bonded to a master plate with all components of an audio amplifier — tube sockets, capacitors, resistors, wiring. It’s a full three tube three stage speech amplifier.
Centralab Ampecs are widely used in hearing aids, for the most trouble-free performance ever attained. Ampec has other interesting applications, as mike pre-amplifier, etc.
The module — without tubes — was an inch and a quarter wide and nearly as long. An Allied Radio catalog described it as “no larger than a book of paper matches” and sold it for $15.29, including the tubes.
The American Radio History site has so many old magazines and catalogs and, as usual, it didn’t let us down when looking for more information about these old components. The December 1949 issue of Radio and Television News (PDF) has the start of a two-part article entitled “Printed Circuits.” The cover with the smiling housewife, beaming at her brand new intercom while her five inch TV set perches next to the sink is priceless, too.
According to the article, Centralab began mass producing printed circuit boards in 1945 for a mortar shell proximity fuse. But these were not printed circuits in the sense that we think of them today. A ceramic substrate was the base for silver and graphite paint applied via silk screen. The silver makes wires and the graphite makes resistors. Seems like conductive ink circuits isn’t at all new concept!
The ceramic was fired in an oven and capacitors were attached. In some cases, conductive paint on both sides of the ceramic would form capacitors, too. Of course, small flat inductors were also possible. Supposedly, inductors could be covered with an insulator and painted with ferrite paint to increase inductance, but that doesn’t sound like it would get you very far. In more modern times, this same basic technique is how you make hybrid thick film circuits, not uncommon in high-reliability applications.
The author notes that you can use other methods such as rubber stamping or lithography to ink the printed circuit board. There was even talk of using decalcomania which is exactly what it sounds like, but I still had to look it up. There were many other methods that didn’t catch on over the long term. For example, “dusting” had metallic dust spread on a substrate and sintered in place much like some metal 3D printing processes. We were especially amused by the cylindrical boards that built circuits around a glass tube.
Build Up and Teardown
The second part of the article (PDF) covers creating your own printed circuits using conductive and resistive paint from DuPont. Since DuPont wasn’t going to sell you a few ounces of these paints, an enterprising Michigan company was selling smaller quantities and kits. You had to find your own substrate and we find it amusing that they suggested using an asbestos board.
A Russian site has a great teardown of an old tape machine that used modules like these. The tape player may look bulky by today’s standards with its large battery and tubes. However, for its day it was quite svelte and cheaper to manufacture thanks to the couplate technology.
It is hard to remember a time when consumer electronics were wired by hand with real wires. We’ve all seen computer backplanes that looked like plates of spaghetti. Printed circuit boards would change the face of electronics forever. Integrated circuit modules, even more. A look at the very early birth of these technologies is sobering when you realize all this was less than 100 years ago.
These methods didn’t last long. By 1969, boards were a bit more like we think of them, although there was still a ways to go. You might enjoy the Tektronix video talking about those kinds of boards, below. And it’s also worth a mention that one of most mesmerizing component assembly periods is tinkertoy and cordwood construction.