The USS Cod is a Gato-class submarine that saw combat in the Second World War and today operates as a museum ship in Cleveland, Ohio. While many other surviving WWII-era subs were cut into pieces or otherwise modified for public display, Cod is notable for being intact and still in her wartime configuration. It’s considered to be one of the finest submarine restorations in the world, and in a recent video from their official YouTube page, we get a look at how 3D printing is used to keep the 82 year old submarine looking battle-ready.
In the video below, President of the USS Cod Submarine Memorial [Paul Farace] is joined by one of the volunteers who’s been designing and printing parts aboard the submarine. While the Cod is in remarkable condition overall, there’s no shortage of odd bits and pieces that have gone missing over the sub’s decades of service.
Surface mount devices have gotten really small, so small that a poorly timed sneeze can send your 0603 and 0402 parts off to live with the dust motes lurking at the edge of your bench. While soldering such parts is a challenge, it’s not always size that matters. Some parts with larger footprints can be a challenge because of the pin pitch, and getting them to land just right on the PCB pads can be a real pain.
To fight this problem, [rahmanshaber] came up with this clever custom PCB fixture. The trick is to create a jig to hold the fine-pitch parts securely while still leaving room to work. In his case, the parts are a couple of SMD ribbon cable connectors and some chips in what appear to be TQFP packages. [rahmanshaber] used FreeCAD to get the outline of each part from the 3D model of his PCB, and KiCad to design the cutouts; skip to 7:30 or so in the video below if you don’t need the design lesson. The important bit is to leave enough room around the traces so that the part’s leads can rest of the PCB while still having room to access them.
Using the fixture is pretty intuitive. The fixture is aligned over the footprint of the part and fixed in place with some tape. Solder paste is applied to the pads, the part is registered into the hole, and you’re ready for soldering. [rahmanshaber] chose to use a hot plate to do the soldering, but it looks like there’s enough room for a soldering iron, if that’s your thing.
This technique shared by [Andy Kong] is for 3D printed lenses, but would probably be worth a shot for any resin prints that need to be made nice and clear. The link to his post on X is here, but we’ll summarize below.
It’s entirely possible to print lenses on a resin printer, but some amount of polishing is inevitable because an SLA print still has layer lines, however small. We have seen ways to minimize the work involved to get a usable lens, but when it comes right down to it the printing process creates tiny (but inevitable) surface imperfections that have to be dealt with, one way or another.
3D-printed lenses fresh (and wet) from the printer look clear, but have tiny surface imperfections that must be dealt with.
One technique involves applying a thin layer of liquid resin to the surface of the printed lens, then curing it. This isn’t a complete solution because getting an even distribution of resin over the surface can be a challenge. [Andy] has refined this technique to make it ridiculously simple, and here’s how it works.
After printing the lens, place a drop of liquid resin on the lens surface and stretch some cling wrap over the lens. The cling wrap conforms to the shape and curve of the lens while trapping a super thin layer of liquid resin between the cling wrap film and the lens surface. One then cures the resin while holding the cling film taut. After curing, [Andy] says the film peels right off, leaving an ultra-smooth surface behind. No tedious polishing required!
But what about the flat back of the lens? [Andy] suggests that instead of using cling film (which is better at conforming to a curved surface) simply use a drop of resin in a similar way to bond the flat side of the lens to a smooth piece of glass. Or bond the backs of two lenses together to make a duplex lens. This technique opens quite a few possibilities!
Even if one isn’t 3D printing optical lenses, we suspect this technique might be applicable to making crystal-clear 3D prints with a little less effort than would otherwise be needed.
Keep it in mind, and if you find success (or failure!) let us know on the tips line because we absolutely want to hear about it.
The invention of the computer is a tricky thing to pinpoint. There were some early attempts that were not well known and some early attempts that were deliberately secret. [Alan Turing]’s efforts with Colossus were top secret for years, and while that work built on earlier efforts in Poland, [Turing] has as much claim to be the father of computers as anyone. But [Jack Copland] points out in a recent post that the famous computer scientist was also involved in another secret project: Delilah.
While [Turing] is best known for his work breaking ciphers at Bletchley Park, he also put time in on a second project about ten miles away in a secret electronics lab at Hanslope Park. There he worked with an assistant, [Donald Bayley] on Delilah — a portable system for encrypting voice transmissions.
For better or worse, the fundamental design of guitars has remained familiar since they electrified around a century ago. A few strings, a fretboard, and a body of some sort will get you most of the way there for an acoustic guitar, with the addition of electromagnetic pickups and wiring for electric variants. However, technology has advanced rapidly in the last 100 years outside the musical world, so if you want to see what possibilities lie ahead for modernizing guitars take a look at the Cyberbass created by [Matteo].
The guitar starts its life as many guitars do: with a block of wood. One of the design goals was to be able to use simple tools to build the guitar, so the shape of the instrument was honed with a Japanese hacksaw and the locations for the pickups and other electronics were carved out with chisels.
The neck of the guitar was outsourced since they take some pretty specialized tools to build, so simply bolting it to the body takes care of that part of the build, but [Matteo] had a few false starts setting the bridge in the exact location it needed to be.
Luckily he was able to repair the body and move the bridge. With the core of the guitar ready, it was on to paint and then to its custom electronics. [Matteo] built in not only a set of pickups and other common electric guitar parts but also integrated a synth pedal into the body as well as including a chromatic tuner.
With everything assembled and a few finishing touches added including a custom-engraved metal signature plate, the Cyberbass is ready to go on tour. [Matteo] learned a lot about guitar building in general, as well as a few things about electronics relating to musical instruments (including how expensive tuners work just as well as cheap ones).
When live-action role playing, or LARPing, one must keep fully in tune with the intended era. That means no digital watches, and certainly no pulling out your fantastic rectangle from the future to find out if you’re late picking up the kid.
So what do you do when you’re LARPing at 2 PM, but you gotta be back at the soccer practice field by 5 PM? Well, you fashion a period-appropriate timepiece like [mclien]’s 17 o’ Clock. Visually, it’s about as close to a pocket sundial as you can get. It’s deliberately non-connected, and its only function is to tell the time.
But how? If you visually divide the watch across the top and bottom, you get two sets of Roman numerals. The top half handles the hour, and the bottom half the minute. [mclien] started designing this in 2018 and picked it back up in the second half of 2024.
Back to the non-connected part. The only permanently-powered part of the project is a high-precision real-time clock (RTC). The rest uses a power latching circuit, which turns on the Adafruit Trinket M0 to show the time using a NeoPixel ring. Be sure to check out the awesome project logs with fantastic pictures throughout.
If you watch the New Year’s festivities from New York, you know that they mark midnight with the dropping of a big, gaudy ball. You might assume this was just an arbitrary gimmick, but it turns out dropping balls has a place in the history of timekeeping, especially for ships at sea. The New York ball doesn’t work precisely the same, but it was clearly inspired by an ancient method of indicating the time.
Apparently, even the ancient Greeks used ball dropping to indicate time. But the modern ball got its start with [Captain Robert Wauchope], who installed one at Portsmouth, England, in 1829. The Royal Observatory in Greenwich got one in 1833, which you can see working in the video below.
