This week, we’re taking the wayback machine to 1940 for an informative, fast-paced look at the teleprinter. At the telegram office’s counter, [Mary] recites her well-wishes to the clerk. He fills out a form, stuffs it into a small canister, and sends it whooshing through a tube down to the instrument room. Here, an operator types up the telegram on a fascinating electro-mechanical device known as a teleprinter, and [Mary]’s congratulatory offering is transmitted over wires to her friend’s local telegraph office hundreds of miles away.
We see that the teleprinter is a transceiver that mechanically converts the operator’s key presses into a 5-digit binary code. For example, ‘y’ = 10101. This code is then transmitted as electrical pulses to teleprinters at distant offices, where they are translated back into alphanumerical data. This film does a fantastic job of explaining the methods by which all of this occurs and does so with an abstracted, color-coded model of the teleprinter’s innards.
The conversion from operator input to binary output is explained first, followed by the mechanical translation back to text on the receiving end. Here, it is typed out on a skinny paper tape by the type wheel shown above. Telegraphists in the receiving offices of this era cut and pasted the tape on a blank telegram in the form of meaningful prose. Finally, it is delivered to its intended recipient by a cheeky lad on a motorbike.
A few years ago the name of the game was tiny, credit card-sized ARM boards. It had to come to this: a 64-bit board. ARM Cortex A53 running at 1.2GHz. It also costs $120 and only has a gig of RAM, but there you go.
This will come to no surprise to anyone who has ever talked to me for more than a few minutes, but one of my guilty Internet pleasures is heading over to eBay’s ‘vintage computing’ category, sorting by highest price, and grabbing a cup of coffee. It’s really just window shopping and after a while you start seeing the same things over and over again; Mac 512s with a starting bid far more than what they’re worth, a bunch of old PC-compatible laptops, and a shocking amount of old software. For the last week I’ve been watching this auction. It’s a Commodore 65 prototype – one of between 50 and 200 that still exist – that has over 60 bids, the highest for over $20,000 USD. It’s the most successful vintage computer auction in recent memory, beating out the usual high-profile auctions like Mac 128s and Altair 8800s. The most valuable home computer is the Apple I, but if you’re wondering what the second most valuable one is, here you go.
The C65 is not a contemporary of the C64, or even our own [Bil Herd]’s C128. This was the Amiga era, and the C65 was intended to be the last great 8-bit machine. From a page dedicated to the C65, it’s pretty much what you would expect: the CPU is based on a 6502, with the on-die addition of two 6526 CIA I/O controllers. The standard RAM is 128kB, expandable to 8MB by an Amiga 500-like belly port. Sound would be provided by two SIDs, and the video is based on the VIC-III, giving the C65 a pallette of up to 4096 colors and a resolution of up to 1280×400.
There’s still a little over five hours to go in the auction, but the current $21000 price should go even higher in the final hour; a C65 auction from a few years ago fetched $20100 for ‘a computer with missing parts’. This auction is for a complete, working system that has remained intact since it was discovered during the Commodore closing.
It’s amazing how affordable PCB fabrication has become. It has long been economical (although not always simple) to fabricate your own singe and double-sided boards at home, the access to professional fabrication is becoming universal. The drive continues downward for both cost and turnaround time. But there is growing interest in the non-traditional.
Over the last year we’ve seen a huge push for conductive-ink-based PCB techniques. These target small-run prototyping and utilize metals (usually silver) suspended in fluid (think glue) to draw traces rather than etching the traces out of a single thin layer of copper. Our question: do you think conductive in will become a viable prototyping option?
Voltera V-One Circuit Board Prototyping Machine
I recorded this interview at 2015 CES but was asked not to publish it until their crowd funding campaign went live. If you haven’t been paying attention, Voltera is at almost 400% of their $70k goal with 26 days remaining. This printer definitely works. You can print circuits, solder components or reflow them, and there’s even a second non-conductive ink that can be used to insulate between traces when they cross over one another. In the video [Alroy] suggests Voltera for small production runs of 10-20 boards. Would you see yourself using this for 10-20 boards?
Personally, I think I could solder point-to-point prototypes in less time. Consider this: the V-One will print your traces but you still must solder on the components yourself. If the board design reaches a high level of complexity, that timing may change, but how does the increased resistance of the ink compared to copper traces affect the viability of a board? I assume that something too complex to solder point-to-point would be delving into high-frequency communications (think parallel bus for LCD displays, etc.). Is my assumption correct? Do you think conductive ink will get to the point that this is both viable and desirable over etching your own prototypes and how long before we get there?
Now, I certainly do see some perfect use-cases for Voltera. For instance, introduction to circuit design classes. If you had one of these printers at the middle school or high school level it would jump-start interest in electronics engineering. Without the need for keeping chemical baths like Cuperic Chloride or Ferric Chloride on hand, you could walk students through simple board design and population, with the final product to take home with them. That’s a vision I can definitely get behind and one that I think will unlock the next generation of hardware hackers.
Correction: [Arachnidster] pointed out in the comments that Voltera is still working on being able to reflow boards printed by the V-One. On their Kickstarter page they mention: “(Reflow onto Voltera printed boards is currently under development)”
Space. The final frontier. Every tinkerer, hacker, and maker has dreamed of flying out of Earth’s atmosphere and into the heavens. Last year one hard-working team got a chance to fly a member to space by winning the Hackaday prize. For the rest of us, we can still experience some of that excitement by contacting satellites in orbit, or even sending a bit of our own hardware into space. This week’s Hacklet focuses on the best satellite projects on Hackaday.io!
We start with [movax] and Your satellite devkit and launch. Chipsat is a tiny satellite which runs BASIC code. Yes, BASIC in space! Chipsats will be stacked into a launcher and sent off into space in groups. The idea is to eventually have them launched from the International Space Station. Power is provided by a small solar cell which charges up a pair of super capacitors. When the capacitors are charged, the satellite will run for a few seconds. Connectivity with the ground is via a 433 MHz link. Chipsat doesn’t just float in space, three coils give it the ability to control its attitude and rotation. Chipsat will sense the space around it with a magnetometer and a light sensor.
No satellite-themed Hacklet would be complete without [Pierros Papadeas] and his team’s work on SatNOGS – Global Network of Ground Stations. SatNOGS aims to create a global network of connected satellite ground stations. Think of it as a grass-roots version of NASA’s deep space network for satellites in earth orbit. This is more than just a great idea, as SatNOGS won the 2014 Hackaday Prize. You can check out our coverage of the project back in November, 2014. Since then, the SatNOGS team has been busy! They’ve just deployed the first SatNOGS V2 system above their hackerspace in Athens, Greece.
Next up is TRSI PocketQub Satellite, another project by [movax]. TRSI is a satellite that sends data via images which can be viewed with a simple RTL-SDR stick using Hellschreiber mode. Hell mode means that images can be directly viewed in the waterfall display of whichever SDR application is running the receiver. Numbers or entire images snapped with TRSI’s cell phone style camera module can be encoded and displayed. Power is of course provided by solar cells, and the communications link will be on the coordinated 433 MHz band. The original TRSI hardware has actually morphed into a deployment machine for ChipSat, [morvax’s] other satellite project. He’s put the main TRSI program on hold until after the ChipSat campaign is complete.
Rounding out our satellite special is [OzQube] with his project QubeCast Max. QubeCast is the first Australian version of the PocketQube PQ60 satellite form factor. After watching the success of $50Sat project, [OzQube] wanted to design a satellite of his own. Since he wanted to add sensors and send more data back to Earth than previous efforts, he needed a higher data rate than the current crop of satellites. This meant going to a high-powered radio. To achieve this, he’s using a NiceRF RF4463F30 radio module. The module is based upon a Silicon Labs Si4463 RF ISM band chip, coupled with a power amplifier. The module outputs 1 watt, which is quite a bit of power for a tiny satellite!
It’s been a little over a year since Makerbot introduced their new line of printers, and since then there have been grumblings about the quality of the Smart Extruder that each one of these printers comes with. While there is no 3D printer extruder that will not eventually clog, wear down, or otherwise break, there are reports of the Makerbot Smart Extruder failing in only hundreds or even tens of hours of use. Considering that a single large print can take a dozen or so hours to complete, you can easily see the why the Smart Extruder is so despised and why even the availability of a three-pack of Smart Extruders is a joke in the 3D printing community.
Of course a cheap shot at Makerbot that plays right into your preconceived ideas and prejudices is far too easy. We’re here to solve problems, not just state them, so here’s what we’re working with: to quantify the long-term reliability of 3D printers we need a way to measure the mean time before failure of extruders. This is already a solved problem; it’s just not implemented.
On aircraft and some very expensive engines that power things like buildings and ships, there’s one gauge, tucked away in the control panel, that keeps track of how long the engine has been running. It’s called a hobbs meter, and the idea behind it is extremely simple – when there is power going to the Hobbs meter, it counts out hours on a small clockwork display. The resolution of the display is only tenths of an hour, usually, but that’s good enough for scheduling maintenance and to be mentioned in NTSB accident reports.
Spend enough time with a 3D printer, and you’ll quickly realize the ‘estimated print time’ is merely a ballpark, and with failed prints the ‘total print time for this object’ isn’t exactly a perfect measure of how many hours you’ve been using your extruder. Only by directly measuring how many hours are logged on a hot end or how many kilometers of filament have been sent through an extruder will you ever get an accurate idea of how long an extruder has been running, and how reliable a printer is.
Hobbs meters are available from Mouser, but you’ll be overpaying there. The better option is from a vendor in a different niche; $30 for a meter that can connect directly to the extruder heater. If enough people add this and keep proper logs, there’s a slight chance of improving the state of 3D printers with real data and not the prejudices of people trying to justify their own designs and purchases.
But perhaps that’s too hard; adding a $30 item to a printer’s BOM just for the sake of data is a bit much. Luckily, there’s an even simpler solution that won’t cost a dime. Just measure the time a heater has been on in the firmware, or save the total length of extruded filament in a microcontroller’s EEPROM. Every printer firmware out there, from Marlin to Repetier to Sprinter has in it a way to calculate both the length of time a heater has been on or how much filament has been pushed through a nozzle.
Secondly, if we’re not going with mechanical Hobbs meters there would need to be a ‘total time heater on’ or ‘total length of extruded filament’ variable in the various firmwares. There would hopefully be standardized Gcodes or Mcodes to read and reset this variable.
Will this happen? Of course not. Organization isn’t a strong suit of the RepRap project, and any company that implements Hobbs meter functionality will probably lock that up in proprietary obfuscation. However, Makerbot isn’t dumb, and given they’re selling three-packs of extruders, I would bet they have some data on the MTBF of their extruders. A community-based measurement of the most common cause of broken printers is certainly possible, but like all problems it’s one of organization, not technology.
3D Printering is a semi-weekly column that digs deep into all things related to 3D Printing. If you have questions or ideas for future installments please sending us your thoughts.
Whether you’ve been following Retrotechtacular for a while or have firsthand experience with the U.S. Army, you know that when they want to teach something to a someone, they’ll get the job done in spades with a side of style. The era between WWII and the Vietnam War was a golden age of clear, simple instruction that saw the Army use memorable material to teach a wide array of topics. And speaking of golden ages, the Army found success with comic book-style instructional magazines drawn chiefly by [Will Eisner] of Spirit fame.
The first of these rags was called Army Motors, which premiered in 1940.It introduced several memorable characters such as a Beetle Bailey-esque bumbling soldier named Private Joe Dope, and no-nonsense gal mechanic Connie Rodd, a sharp cookie who’s as brainy as she is buxom. Educational and entertaining in equal parts, the magazine was pretty well received.
Its successor, known simply as P.S. started its run around the beginning of the Korean War in June 1951. These magazines were intended as a postscript to the various equipment maintenance manuals that soldiers used. They offered all kinds of preventive maintenance procedures as well as protips for Army life. The eye-catching depictions of Connie Rodd demanded soldiers’ attention while the anthropomorphic equipment illustrations encouraged them to listen to what their equipment told them.
Additional artists including [Joe Kubert] and [Dan Spiegle] were brought in to produce P.S. on a monthly basis. As the years marched on, the magazine’s character base expanded to include representatives of other military branches solving specialized problems. The bumbling idiot types were 86’d pretty early on, but cheesecake was served well into the 1970s.
Did we mention that they’re still making P.S.? Here’s the February 2015 issue and a friendly PDF warning.