When [Patrick Hickey] spent a tidy sum on eBay to purchase a pair of seven-segment displays used in the Launch Control Center at Kennedy Space Center during the Apollo program, he could have just put them up on a shelf. It’s certainly what most people would have done. Instead, he’s decided to study and document their design with the hope of eventually creating 3D replicas of these unique pieces of NASA history.
With a half century now separating us from the Moon landing, it’s more important than ever to preserve the incredible technology that NASA used during mankind’s greatest adventure. Legitimate Apollo-era hardware is fairly scarce on the open market, and certainly not cheap. As [Patrick] explains on the Hackaday.io page for this project, being able to 3D print accurate replicas of these displays is perhaps the best way we can be sure they won’t be lost to history.
But more than that, he also wants others to be able to see them in operation and perhaps even use them in their own projects. So that means coming up with modern electronics that stand-in for the 60s era hardware which originally powered them.
Since [Patrick] doesn’t have access to whatever (likely incandescent) lighting source these displays used originally, his electronics are strictly functional rather than being an attempt at a historic recreation. But we have to say, the effect looks fantastic regardless.
Currently, [Patrick] is putting most of his efforts on the smaller of the two displays that he calls “Type A”. The chunk of milled aluminum with integrated cooling fins has a relatively simple shape that should lend itself to replication through 3D scanning or even just a pair of calipers. He’s also put together a proof of concept for how he intends to light the display with 5mm LEDs on a carefully trimmed bit of protoboard, which he plans on eventually refining to reduce the number of wires used.
One aspect he’s still a little unsure of is how best to replicate the front mask. It appears to be made of etched metal with an integrated fiberglass diffuser, and while he’s already come up with a few possible ways to create a similar front panel for his 3D printed version, he’s certainly open to suggestions from the community.
This isn’t the first time we’ve seen a dedicated individual use 3D printing to recreate a rare and expensive object. While the purists will say that an extruded plastic version doesn’t compare to the real thing, we think it’s certainly better than letting technology like this fade into obscurity.
[Peter Lehnér] has designed a brilliant 7-segment flip-segment display that doesn’t really flip. In fact, it doesn’t use electromagnets at all. This one is 3D printed and hand cranked. It’s a clever use of a cam system to set the segments for each digit (0-9) makes it a perfect entry in the Hackaday 3D Printed Gears, Pulleys, and Cams contest.
We find the nomenclature of these displays to be a bit confusing so let’s do a quick rundown. You may be most familiar with flip-dot displays, basically a dot-matrix grid of physical pixels that are black on one side and brightly colored (usually chartreuse) on the other. We saw a giant flip-dot display at CES four years ago. Akin to flip-dots are flip-segment displays which do the same thing but with segments of a digit rather than dots. We featured a 3D printed version of these last week. The common aspect of most flip displays is an electromagnet used to change the state of the dot or segment.
The version [Peter] designed gets rid of the magnets and coils, replacing them with mechanical logic instead. Each segment sits in a track on the frame of the digit. When slid to one position it is hidden by the bezel, in the other position it slides into view. A cleverly designed set of cams move the segments at each of 10 positions. The animated graphic here shows three cams which are responsible for moving just two of the segments. More cams are added to complete assembly, a process shown in the second half of the demo video found below.
We’re delighted to see this as an entry in the contest and can’t wait to see what kind of gear, cam, or pully scheme is built into your projects!
Continue reading “7-Segment Display Is 3D Printed And Hand Cranked”
This looks like one of those projects that started out as a glimmer of an idea and led down a rabbit hole. But it’s a pretty cool rabbit hole that leads to homebrew neon seven-segment displays on a calculator with relay logic.
It’s a little thin on documentation so far, but that’s because [Mark Miller]’s build is one of those just-for-the-fun-of-it things. He started with a bag full of NE-2 tubes and the realization that a 3D-printed frame would let him create his own seven-segment displays. The frames have a slot for each segment, with a lamp and current limiting resistor tucked behind it; with leads brought out to pins and some epoxy potting, these displays would be hard to tell from a large LED seven-segment. Rolling your own displays has the benefit of being able to extend the character set, which [Mark] did with plus-minus and equal sign modules. All of these went together into a two-banger calculator — addition and subtraction only so far — executed in relays and vacuum tubes. Version 2.0 of the calculator regressed to all-relay logic, which must sound great.
We heartily regret the lack of a satisfyingly clicky video, but we’ll give it a pass since this is so cool. We’ll be watching for more on this project, but in the meantime, if you still need to get your click on, this electromechanical BCD counter should help.
[Absolutelyautomation] has a problem with seven-segment displays. Fitting these displays in an enclosure is a pain because you can’t drill perfectly square holes, and you will invariably mess up a few enclosures with overzealous file work. There is a solution to this problem – panel mount meters.
The bezels on these panel mount meters hide the imperfections in the enclosure, and usually don’t require screws. They are, however, dedicated displays, usually for temperature, RPM, or some other measurement.
[Absolutelyautomation] took one of these dedicated panel mount displays and turned it into an all-purpose device. Basically, it’s a panel mount Arduino with three seven-segment displays.
This project is built on perfboard cut down to fit inside the enclosure of a very cheap panel meter found at the usual suppliers. Tucked away underneath this perfboard is an ATmega, a few resistors, and the support parts to make everything go. This panel mount meter can either be a serial slave or as a standalone controller, programmable with the Arduino IDE. It’s cheap, too. You can check out [Absolutelyautomaion]’s video below.
Continue reading “Panel Mount Display Solves The Problem Of Drilling Square Holes”
A while back, [limpfish] bought a few four-digit seven-segment displays from a seller on eBay. A month or two later, thirty displays ended up in [limpfish]’s mailbox. Instead of using the one or two displays he thought he ordered, [limpfish] decided to do something very cool with these bits of seven-segment displays. He’s controlling all of them at once.
[limpfish]’s usual method of controlling a lot of LEDs is the MAX7219 LED driver. This chip can easily — and cheaply — control eight common cathode seven segment displays. There’s a problem with this plan, though: the LEDs received from eBay are common anode. That’s actually not a problem, because with a little effort and even more thinking [limpfish] got these displays to work with the MAX7219 driver chip.
With chips in hand, [limpfish] designed a small breakout board for the MAX7219 and two common anode 4×7 segment displays. These displays can be daisy chained, and connecting them all together results in a very weird but very cool visualization.
[limpfish] is treating this display as a bitmap display, which means it’s demo time. You can check out a 1337 01d skool demo playing on this 840-segment display in the video below.
Continue reading “An 840 Segment Display”