We’re not sure if [Derek Lieber] is messing with us or proving a point. Why are you doing this [Derek]? We know there’s technically enough information to build the clock. You even included the code. Couldn’t you have at least thrown in a couple of words? Do we have to skip straight to mediaglyphics?
Anyway, if we follow the equation. The equation… If you take a gps module, a 7 segment display with an HT16K33 backpack, a digital potentiometer, a piezo, and a boarduino we suppose we could grudgingly admit that these would all fit together to make a clock. We still don’t like it though, but we’ll admit that the nice handmade case was a nice touch, and that the pictures do give us enough details to do it ourselves.
It was also pretty cool when you added the Zelda theme song as an alarm sound. Also pretty neat that, being GPS corrected, there’s no need to ever set the time. We may also like the simplicity of the only inputs being the potentiometer, which is used to set the alarm time. It’s just. Dangit [Derek]. Nice clock build, we like it.
As many of the members of the Brian Benchoff hate/fan club know, the life of a Hackaday writer is nomadic and filled with exciting adventures. Jenny List is actually crime fighting cyborg (think Bond); it’s why she knows so much about electronics. James Hobson is Iron Man. The list goes on. There are lots of unnecessary details, but to summarize: Last month I was living in Washington State, this month I am in Paris, France. It’s really nice here, the buildings are beautiful, the cathedrals stunning, and the food significantly tastier.
However, as a contracting engineer with a project involving a deadline; I found myself in dire need of a significant amount of quick turn-around 3D printing during my working vacation to France. Through a lot of trial and tribulation, I eventually discovered that the most cost-effective way to get the prints done… was to just buy a cheap 3D printer and run it into the ground.
I was spoiled by my hackerspace in Louisville, KY. They had enough 3D printers to go around and the pricing was fixed at 10 cents a gram. For the amount of printing I needed, this would be a perfectly economical arrangement. So, I set out to find a hackerspace in Paris. Whereupon I reached my first and obvious problem; I speak very little French.
Most of the hackerspaces listed in Paris are, as far as I can tell, illegally squatting in a scary part of town, exclusive to a university, exclusive to a business, or closed down.
So, I googled a bit harder. Wow! Apparently a Techshop opened up in Paris. It’s about an hour away from where I live, but having toured a Techshop before, I knew they would have the nice version of the tool I need. So, one morning bright and early I got on the metro and headed over to get a tour of the place.
What I’ve discovered is this: If you need things like a water jet cutter, welding station, or a 50 grand CNC machine, Techshop is a really economical way to get access to and play with tools like that. However, if all you want is access to a laser cutter and a 3D printer, it will set you back five-hundred dollars and you’ll have to jump through some incredibly annoying hoops just to get access to them.
See, most pieces of equipment at a Techshop need to be reserved. Only the 150 euro and 300 euro a month membership tiers can reserve equipment. The 150 tier can reserve something for two hours, the 300, four. If you’ve ever 3D printed you can immediately spot the problem with that. For small prints this could be workable, but if you have a lot of large prints four hours is just not enough. However, there is a work around. If you’re willing to take a metro ride late at night, arriving at the Techshop at 10:00pm, you can, of course, run a print overnight.
There were two more glitches in the Techshop plan. To be able to touch the printers required a two-hour course with a 100 euros fee. The filament also ran 65 euro per 500 g. My printing needs would easily cost me tens of hours in travel and had a starting fee of 400 euros to be workable.
Now, I’m not saying Techshop isn’t absolutely wonderful when it comes to more advanced tools. It’s probably the only Hackerspace in the world where you’re entitled to expect that the CNC machine is in working order, properly trammed, and there are actually cutting bits for it. However, if all you need is a 3D printer, don’t bother.
Now, I asked around some more and found that there was a competing space in Paris called Usine.io. It had a flat fee of 180 euros a month and the training was free. I actually did end up getting a membership here for access to a CNC and basic tools, but for 3D printing it was a bust. They only had three printers serving a sizable membership base. This left the printers with a 48 hour line to get your print started and a maximum of 40 hours of printing a month. A die-hard user of 3D printing can easily use 40 hours in 3 days. Because I had to test many iterations for my project, my need the next month was easily triple that number.
The last avenue available to me aside from 3D printer ownership was contracting someone with a 3D printer to run my prints for me. However, after asking around I found the service to be quite expensive. Rent isn’t cheap in Paris after all. If I just needed a single small print it would be worth it, but if I needed lots of printing it would quickly add up to be more money than I had.
That left me with one option. Which, honestly, sounded absolutely insane for someone visiting a country for a few months. Buy a printer. It’s an indication of the state of 3D printing that the price has come down so far that buying a printer is more economical than having someone do it for you. Even a few years ago this was not possible. However, European Amazon Prime had a workable enough import printer to my doorstep faster than any commercially available service could even process my order. We’ve come a long way since the Darwin. That’s for sure.
The build is based on the designs described in the book “Build an EDM” by Robert Langolois. An EDM works by creating lots of little electrical discharges between an electrode in the desired shape and a material underneath a dielectric solvent bath. This dissolves the material exactly where the operator would like it dissolved. It is one of the most precise and gentle machining operations possible.
His EDM is built mostly out of found parts. The power supply is a microwave oven transformer rewired with 18 gauge wire to drop the voltage to sixty volts instead of the oven’s original boost to 1.5kV. The power resistor comes from a dryer element robbed from a unit sitting beside the road. The control board was etched using a hand traced schematic on the copper with a Sharpie.
The linear motion element are two square brass tubes, one sliding inside the other. A stepper motor slowly drives the electrode into the part. Coolant is pumped through the electrode which is held by a little 3D printed part.
The EDM works well, and he has a few example parts showing its ability to perform difficult cuts. Things such as a hole through a razor blade., a small hole through a very small piece of thick steel, and even a hole through a magnet.
[David]’s family acquired a swimming pool. While it’s not his favorite activity in the world, every now and then he’ll indulge in the blue plastic bin full of water occupying previously pristine land in his backyard.
As he says, cool beer is pleasant, but cool water tends to put a damper on the experience. Rather than do something pedestrian like touch the water himself to discover its temperature; he saw an opportunity for a fun little project in a wireless temperature monitor.
The heart of the device is a Telecom Design TD1208 which runs on the French SigFox network. For a small fee any device on the network can send up to 140 12byte packets of data a day. Not a lot, but certainly acceptable for the Microchip MCP9700 temperature sensor it uses. He got the board up and running, and even made his own custom helical coil antenna.
The case was 3D printed out of PLA. It’s a tiered cylindrical bobber. The wider top section floats on the water and the base acts as a ballast, holding the battery and sensor. The bobber is powered by a combination of a questionable Chinese lithium battery, charging circuit, and solar panel. [Dave] was keen to point out that the battery is, technically, water cooled.
He wrapped up the code for the bobber and used SigFox’s SDK to build a nice web interface. Now, when the rare mood strikes him, he can remain inside if the conditions aren’t right for a swim.
[Drygol] found himself with six Commodore 64’s in various states of disrepair. Because batch work is often more efficient, he detailed the process of restoring all of them in parallel in this one-, two-, three-part series.
The first step was to whiten the cases. Old cases turn yellow from the degradation of the fire retardant additives in the plastic. The proven method to fix this is with a paste called Retr0bright. [Drygol] used hair bleaching paste which is very similar. The cases came out nicely whitened from their treatment.
Next he repaired the keyboard PCB and whitened the keys as well. Drinking was involved, but it all came out okay. The circuit boards were cleaned and inspected. There were a few corroded spots, broken chips, and bad solder joints to be repaired. A few common mods were also installed.
In the final part of the series two of the C64s have SD cards installed into them. A few interesting fixes were done to repair broken plastics. Lastly the two worst cases were painted. In the end [Drygol] found himself with six perfectly working and attractive C64s. Who know’s what he’ll do with them, but we all know that was not the point.
There’s nothing wrong with the rough experiments like hanging a 1 L bottle of water from the end of a rectangular test print to compare strengths. We also have our rules-of-thumb, like expecting the print to perform at 30% of injection molded strength. But these experiments are primitive and the guidelines are based on hearsay. Like early metallurgy or engineering; 3D printing is full of made-up stuff.
What [Sam] has done here is really amazing. He’s produced a model of a printed ABS part and experimentally verified it to behave close enough to the real thing. He’s also set a method for testing and proposed a new set of questions. If it couldn’t be better, he also included his full research notebook. Make sure to read the FDMProperties-report (PDF) in the files section of Hackaday.io.
If research like this is being done elsewhere, it’s either internal to a large 3D printer manufacturer, or it’s behind a paywall so thorough only the Russians can help a regular peasant get through to them. Anyone with access to a materials testing lab can continue the work (looking at you every single engineering student who reads this site) and begin to help everyone achieve an understanding of 3D printed parts that could lead to some really cool stuff one day.
Slit lamps are prohibitively expensive in the third world areas of India where they are most needed. An invention that’s been around for over a hundred years, the slit lamp is a simple-in-concept way to see and diagnose a large array of ocular issues.
Since they are relatively old by technological standards, the principles behind them have become more and more understood as time has gone on. While a nice lab version with a corneal microscope is certainly better, innovations in manufacturing have brought the theoretical minimum cost of the device way down, or at least that’s what [Kewal Chand Swami] hopes.
His design aims for portability and cost reduction. It must be able to travel to remote locations and it must be significantly cheaper than the lab versions. It uses off-the-shelf lenses in a 3D printed housing with a simple LED torch, the kind you can buy for a dollar at the check-out stand.
The assembly slides onto the user’s head and is held there with straps. The doctor can adjust where the slit the lamp shines and also look through a microscope to diagnose the issue. Hopefully devices like this will see similar community support to the prosthetic projects we’ve covered.