Pinball Table Gets New Lease of Life With Arduino

By Richard Baguley


Forget all of this video game nonsense: pinball is the real king of gaming. After all, it involves large pieces of metal flying around at high speed. [retronics] agrees: he has resurrected an old Briarwood Aspen pinball table using an Arduino.

When he bought the table, he found that the electronics had been fried: many of the discrete components on the board had been burnt out. So, rather than replace the individual parts, he gutted the table and replaced the logic board with an Arduino Mega that drives the flippers, display and chimes that make pinball the delightful experience it is. Fortunately, this home pinball table is well documented, so he was able to figure out how to rewire the remaining parts fairly easily, and how to recreate the scoring system in software.

His total cost for the refurb was about $300 and the junker was just $50 to start with. Now for $350 you can probably find a working pinball table. But that’s not really the point here: he did it for the experience of working with electromechanical components like flippers and tilt switches. We would expect nothing less from the dude who previously built an Android oscilloscope from spare parts.

Filed under:

Via: Hack a Day


The Best of Boston Hackers at Artisan’s Asylum

By Mike Szczys


We were in Boston last week and Artistan’s Asylum welcomed us in to host a Hackaday Meetup. We usually pack the place when the Hackaday community turns out, but this was exceptional. This hackerspace has a sizeable open area that I’m told fits triple-digits and we were using all of it. In addition to food and beverage (courtesy of our parent company Supplyframe who also make trips like this one a possibility), we had lighting talks for people to show off their projects. One of the hits was a functional hoverboard shown above, but there were dozens of others.

Here is the quick gallery of images (from our event page) to give you an overview. After the break you’ll find dozens more highlighting the builds which were being shown off.

We brought the Hackaday Omnibus with us
Gentleman in white makes clothes with hundred+ yo machines
Spaceships made of duct tape
[Jimmy Rogers] and [Sophi Kravitz] having a good time
Lightning talks

The Show and Tell of the Night


[Peter Walsh] brought along a magnetic PCB clamp. This is similar to the StickVise but uses a metal plate with magnets in the clamping bars. It is a bit hard to do fine adjustments — I suggested a spring-loaded side like [Alex Rich] built in his original.

PMOD boards are extensible
2013 Open Hardware Summit Badge

The [engunneer] was showing off his MakerMod system. The idea is to use the PMOD interface standard along with adapter boards for every type of dev board you can imagine (id: Arduino, Raspberry Pi, etc.). He has also extended the standard for passing analog signals as well. I couldn’t resist taking a picture of his BADGEr from Open Source Hardware Summit 2013. [Anool Mahidharia], who joined the Hackaday Crew this year, has been writing a ton of great content and running these types of meetups in India, worked on the design of this badge.

Legacy Driver for a paper tape punch
Tape punch serial plate

[Matthew] has a company called D’asaro Designs that makes drivers for legacy hardware. He brought along a machine that punches paper tape. His custom PIC-based driver module allows you to interface a modern computer with the ancient (but awesome) hardware. It’s satisfying to punch letters in tape in real time.


This light-saber build will soon be open-sourced, something rare in the ecosphere of prop replica. He also built the spacecraft models from duct tape seen at the top of this post.

Artisan's Asylum known for Awesome bikes
Crank to flap 3Doodle printed wings
[Dan] needs help printing these
Solenoid typerwriter plays [Leroy Anderson]

I knew I was getting close to finding Artisan’s Asylum when I was passed by someone on a tall bike. Turns out they make a lot of really cool bikes in the space.

The Butterfly sculpture seen above has delicate wings made with the 3Doodler. There is a metal mechanism supporting it that flaps the wings when you turn the crank.

I met [Dan] at Harvard earlier in the day and he brought along these spring-and-3D-printed-sphere cubes. They represent a simple cube crystal structure. He wants to make a huge network of them, but each row added really ups the number of spheres he has to print. If you’re interested in helping, check out the model and get in touch with him.

The last image in this group is the solenoid-outfitted typewriter that plays [Leroy Anderson's] The Typewriter Symphony. Yes, it is super-awesome in person and a hit of the night, to be sure.

Array of 4 microphones
Processing board serves as "handle" for now

During the lighting talks I spotted [Shen] because I immediately recognized the most beautiful custom-rolled display in the world which was peeking out of the bag he was holding. In addition to showing off that handiwork he was trying out this new directional-microphone he made. The array has four MEMS microphones on it, with signal processing done on the board. It was cool to “tune out” the people to either side of you in exchange for whomever you pointed the thing at.


I’m still looking for video footage of this hoverboard. It’s made with super-dangerous magnets that run about $400 bucks each. I believe the story told was that this was built for the [Jimmy Kimmel] show but I can’t find the segment online. It’s tethered to the base plate make sure it doesn’t violently flip over and slam into it. It’ll support a tall and lanky geeky guy (read: me) no problem.


The hoverboard isn’t the only way to get around this hackerspace. You can walk around in this human-sized-hamster-wheel but you’ll need a spotter so you don’t crush the bystanders.

Discrete logic from SMD parts

We previously featured [Alan] in a Fail of the Week where he had a few electrical issues with a powered kick scooter conversion. But his engineering is strong as proven by this amazing art piece. He and a few buddies got a hold of hundreds of stepper motors for a song. They built this array of colored plastic tubing that is pleasing to the eye and includes many interesting animation patterns. He’s also working on building some logic from discrete SMD parts. He needs 40 of them to make a clock and it currently takes about 40 minutes to solder each… ugh.

Pulley system to pull himself up
Cleat is part of custom built lower pulley

Next door to Artisan’s Asylum is a climbing gym. This hacker is working on his lead-climber certification. He believes he’ll be the third paraplegic lead climber in the world. To assist, he’s come up with some custom equipment. He has a reaching pole for setting anchors above him. He pulls himself up with the help of a pulley system, and ties off the advances with a special cleat he’s built into the bottom pulley.

Finished case will be painted
Can run from 1 or 2 batteries
The guts
"OMG I made my Kickstarter" look

[Sam Feller] was showing off the production version of his Analog Voltmeter Clock. He’s in the process of fulfilling a successful Kickstarter. There are two meters which show hour and minute. He has a rotary encoder and potentiometer for settings, and the entire thing can run off of one AA (although there are two slots if you want to change batteries less often.

Back of inMoov
Working robot built using 3Doodler

There was an inMoov robot on display. I was also interested to see the human skeleton robot which was “printed” using the 3Doodler. It’s incredible what you can do freehand, on the couch, while the TV is playing.

What a wonderful night. Thanks again to everyone who came out, and our hosts at the hackerspace. Boston has a great hacking scene!

Filed under: Hackaday Columns, Hackerspaces

Via: Hack a Day


Find and Repair a 230kV 800Amp Oil-Filled Power Cable Feels Like Mission Impossible

By Anool Mahidharia

How do you fix a shorted cable ? Not just any cable. An underground, 3-phase, 230kV, 800 amp per phase, 10 mile long one, carrying power from a power station to a distribution centre. It costs $13,000 per hour in downtime, counting 1989 money, and takes 8 months to fix. That’s almost $75 million. The Los Angeles Department of Water and Power did this fix about 26 years ago on the cable going from the Scattergood Steam Plant in El Segundo to a distribution center near Bundy and S.M. Blvd. [Jamie Zawinski] posted details on his blog in 2002. [Jamie] a.k.a [jwz] may be familiar to many as one of the founders of Netscape and Mozilla.

To begin with, you need Liquid Nitrogen. Lots of it. As in truckloads. The cable is 16 inch diameter co-axial, filled with 100,000 gallons of oil dielectric pressurised to 200 psi. You can’t drain out all the oil for lots of very good reasons – time and cost being on top of the list. That’s where the LN2 comes in. They dig holes on both sides (20-30 feet each way) of the fault, wrap the pipe with giant blankets filled with all kind of tubes and wires, feed LN2 through the tubes, and *freeze* the oil. With the frozen oil acting as a plug, the faulty section is cut open, drained, the bad stuff removed, replaced, welded back together, topped off, and the plugs are thawed. To make sure the frozen plugs don’t blow out, the oil pressure is reduced to 80 psi during the repair process. They can’t lower it any further, again due to several compelling reasons. The cable was laid in 1972 and was designed to have a MTBF of 60 years.

Finding out the location of the fault itself was quite a feat. It involved time-domain reflectometry (inconclusive), ultrasound, and radar (didn’t work) and then using an Impulse Generator-Tester (Thumper) which got them pretty close to the defective segment. What pinpointed the problem was a bunch of car batteries and some millivoltmeters. They hooked up car batteries to both ends, tapped the cable at several points and knowing the drops and resistance of the cable, got within a few feet of the fault. Finally, X-Ray equipment was brought in. Sure enough, they could see the cable shorting against the steel wall of the pipe. Cutting open, and closing it all up, required certified welders spending up to 8 hours on each section to avoid damage to the paper insulation. The welders placed their thumbs 3 inches away from the seams they were welding, and stopped when it got warm to touch, allowing it to cool off before starting again.

The failure was attributed to “TMB”, short for Thermal Mechanical Bending. TMB causes the cable to wiggle in place due to load surges. This eventually causes insulation failure due to abrasion against the pipe and separation of the many layers of paper tape. They repaired the short, put aluminum collars in most of the joints to hold the splices in place, and have added a load management scheme to reduce the current peaks. Apparently, the fix wasn’t good enough. According to this Wikipedia article, “the 315 megawatt capacity Scattergood Steam Plant (Unit 3) to West Los Angeles (Receiving Station K) 230 kV line is having to be replaced after only 45 years of operations, due to multiple failures within this rather long single-circuit, oil-filled, “pipe type” cable.”

You can read lots of other interesting bits about this repair job from [jwz]‘s blog. Thanks to [J. Peterson] for sending in this tip, which was triggered by our recent post on “

Via: Hack a Day