DIY SLS 3D Printer Getting Ready To Print

March 25, 2022 by Dave Rowntree 12 Comments

Ten years ago the concept of having on our desks an affordable 3D printer knocking out high quality reproducible prints, with sub-mm accuracy, in a wide range of colours and material properties would be the would be just a dream. But now, it is reality. The machines that are now so ubiquitous for us hackers, are largely operating with the FDM principle of shooting molten plastic out of a moving nozzle, but they’re not the only game in town. A technique that has also being around for donkeys’ years is SLS or Selective Laser Sintering, but machines of this type are big, heavy and expensive. However, getting one of those in your own ‘shop now is looking a little less like a dream and more of a reality, with the SLS4All project by [Tomas Starek] over on hackaday.io.

[Tomas] has been busy over the past year, working on the design of his machine and is now almost done with the building and testing of the hardware side. SLS printing works by using a roller to transfer a layer of powdered material over the print surface, and then steering a medium-power laser beam over the surface in order to heat and bond the powder grains into a solid mass. Then, the bed is lowered a little, and the process repeats. Heating of the bed, powder and surrounding air is critical, as is moisture control, plus keeping that laser beam shape consistent over the full bed area is a bit tricky as well. These are all hurdles [Tomas] has to overcome, but the test machine is completed and is in a good place to start this process control optimisation fun. Continue reading “DIY SLS 3D Printer Getting Ready To Print” →

Quick Hacks: Using Staples When Recapping Motherboards

March 22, 2022 by Dave Rowntree 23 Comments

[Marcio Teixeira] needed to recap an old Apple Macintosh motherboard, and came across a simple hack to use common paper staples as a temporary heat shield (video, embedded below) during hot air rework. The problem with hot air rework is minimizing collateral damage; you’re wielding air at a temperature hot enough to melt solder, and it can be take quite a lot of experience to figure out how best to protect the more delicate parts from being damaged. Larger items take longer to heat due to their thermal mass but smaller parts can be very quickly damaged from excess heat, whilst trying to remove a nearby target.

The sharp edges of plastic connectors are particularly prone, and good protection is paramount. Sticky tapes made from polyimide (Kapton), PET, as well as metallic options (aluminium tape is useful) are often used to temporarily mask off areas in danger of getting such collateral overheat. But they can cause other problems. Kapton tape, whilst great at withstanding the heat, tends to distort and buckle up a little when under the blast of the rework pencil. Not to mention that some brands of tape leave a nasty sticky transfer residue all over the board when exposed to heat, which needs additional cleanup.

Maybe a box or two of staples might be worth adding to one’s bag of tricks, after all more options is always good. If you’re less interesting in hacking with a hot air work station and much more in hacking a hot air rework station, here you go, and whilst we’re on reworking duff computers, here’s what happens when a Hackaday writer tries his hand at fixing his son’s Xbox.

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Home Made Scanning Electron Microscope Shows Some Potential

March 21, 2022 by Dave Rowntree 7 Comments

Scanning electron microscopes are one of those niche instruments that most of us don’t really need all the time, but would still love to have access to once in a while. Although we’ve covered a few attempts at home-builds before, many have faltered, except this project over on Hackday.IO by user Vini’s Lab, which appears to be still under active development. The principle of the SEM is pretty simple; a specially prepared sample is bombarded with a focussed beam of electrons, that is steered in a raster pattern. A signal is acquired, using one of a number of techniques, such as secondary electrons (SE) back-scattered electrons (BSE) or simply the transmitted current into the sample. This signal can then be used to form an image of the sample or gather other properties.

The project is clearly in the early stages, as the author says, it’s a very costly thing to build, but already some of the machined parts are ready for assembly. Work has started on the drive electronics for the condenser stigmator. This part of the instrument takes the central part of the rapidly diverging raw electron beam that makes it through the anode, and with a couple of sets of octopole coil sets, and an aperture or two, selects only the central portion of the beam, as well as correcting for any astigmatism in the beam. By adjusting the relative currents through each of the coils, a quadrupole magnetic field is created, which counteracts the beam asymmetry.

Scanning control and signal acquisition are handled by a single dedicated card, which utilises the PIO function of a Raspberry Pi Pico module. The Pico can drive the scanning operation, and with an external FTDI USB3.0 device, send four synchronised channels of acquired sample data back to the host computer. Using PCIe connectors and mating edge connectors on the cards, gives a robust and cost effective physical connection. As can be seen from the project page, a lot of mechanical design is complete, and machining has started, so this is a project to keep an eye on in the coming months, and possibly years!

We have seen a few SEM hacks, here’s a teensy powered SEM hack from [Ben Krasnow] and here’s another attempt. For such a conceptually simple device, with such immense usefulness, its does seem a bit remiss that there aren’t more such projects out there.

ElectronBot: A Sweet Mini Desktop Robot That Ticks All The Boxes

March 20, 2022 by Dave Rowntree 12 Comments

[Peng Zhihui] seems to have found some spare time and energy to crack out another sweet robot build, this time it’s a much smaller, and cuter emoji-bot (Original GitHub Link,) with the usual production-ready levels of attention to detail. With a lot of fine details in the 3D printed models, this is one for SLS printing in nylon, but that can be done for a reasonable outlay, in China at least. The electronics package consists of a few full custom, and tiny, PCBs designed with Altium Designer, with off-the-shelf modules for the circular LCD and camera. The main board hosts an STM32F405 and deals with the display and SD card, The reason for this choice of STM32 was due to the requirement for connecting to an external USB3300 high-speed USB PHY. There is a sensor PCB which handles the gesture sensor, a USB hub, MPU6050 9-axis sensor, and also the USB camera module. This board attaches to the USB-C connector in the base, via a FFC cable, allowing the robot to rotate on its base.

[Peng] clearly has exacting standards as to how things should work, and we guess wanted to have the arms back-driveable in a way that enabled the host computer to track and record the motor positions for replaying later on. The connection back to the controller is via I²C, allowing all five servos to hang on the same bus, saving previous resources. Smart! Getting a processor and motor driver in such a tiny space was a bit of challenge, but a walk in the park for [Peng] as is demonstrates in the video embedded below (We believe English subtitles are pending!) The arm mechanism is particularly interesting, and rather elegantly executed, and he does seem rather proud of this part of the design, and so he should! Like with [Peng’s] other projects, there is a lot to see, and plenty of scope for feature explosion. It was nice to see the ‘bot being used as an input device, not only with gesture sensing via the dedicated sensor, but also using the camera with OpenCV to track user posture and act accordingly. This thing could act as genuinely useful AI device, as was a being darn cute at the same time!

We know you come to Hackaday for your cute robot fix, and we’re not going to disappoint. Here’s a cute robot lamp, an obligatory spot (a robot dog) type project, and if you’re more of a cat person, then we got that base covered as well.

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Remoticon 2021 // Arsenijs Tears Apart Your Laptop

March 17, 2022 by Dave Rowntree 9 Comments

Hackaday’s own [Arsenijs Picugins] has been rather busy hacking old laptops apart and learning what can and cannot be easily reused, and presents for the 2021 Hackaday Remoticon, a heavily meme-loaded presentation with some very practical advice.

Full HD, IPS LCD display with touch support, reused with the help of a dedicated driver board

What parts inside a dead laptop are worth keeping? Aside from removable items like RAM stick and hard drives, the most obvious first target is the LCD panel. These are surprisingly easy to use, with driver boards available on the usual marketplaces, so long as you make sure to check the exact model number of your panel is supported.

Many components inside laptops are actually USB devices, things like touch screen controllers, webcams and the like are usually separate modules, which simply take power and USB. This makes sense, since laptops already have a fair amount of external USB connectivity, why not use it internally too? Other items are a bit trickier: trackpads seem to be either PS/2 or I²C and need a bit more hardware support. Digital microphones mostly talk I²S, which means some microcontroller coding.

Some items need a little more care, however, so maybe avoid older Dell batteries, with their ‘spicy pillow’ tendencies. As [Arsenijs] says, take them when they are ripe for the picking, but not too ripe. Batteries need a little care and feeding, make sure you’ve got some cell protection, if you pull raw cells! Charging electronics are always on the motherboard, so that’s something you’ll need to arrange yourself if you take a battery module, but it isn’t difficult, so long as you can find your way around SMBus protocol.

These batteries are too ripe. Leave them alone.

Older laptops were much more modular and some even designed for upgrade or modification, and this miniaturization-driven trend of shrinking everything — where a laptop now needs to be thin enough to shave with — is causing some manufacturers to move in a much more proprietary direction regarding hardware design.

This progression conflicts with our concerns of privacy, repairability and waste elimination, resulting in closed boxes filled with unrepairable, non-reusable black boxes. We think it’s time to take back some of the hardware, so three cheers to those taking upon themselves the task to reverse engineer and publish reusability information, and long may it be possible to continue.

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Doubled Up 3D Printer Upgrade Doubles The Fun

March 17, 2022 by Dave Rowntree 19 Comments

[Nathan] from Nathan Builds Robots on YouTube is no stranger to modding 3D printers, whether it’s a good idea or not, it’s just fun to find out sometimes. His latest escapade he calls the Double Ender (video, embedded below), where he not only doubles up the hotend, but the doubles up a few other bits too. The aim was to achieve dual material printing, with his specific goal to combine plain nylon and carbon fiber-loaded nylon in the same print, to get the best properties of both materials.

Taking a stock Ender 3 v2, [Nathan] first installs a dual Z axis kit, doubling up the Z axis screw and associated stepper motors. Likely this was needed to compensate for the additional weight of subsequent mods. Since the stock Ender mainboard has only one Z axis port, the less obvious solution was to just install a second mainboard! By leveraging the immense hackability of the Klipper printer firmware/software stack,he was able to get this weird configuration to work.

Next the main part of the build; the Phaetus Tai Chi dual hot end installation. For some reason, initially, it was decided to combine the stock bowden injector/extruder with a direct drive second unit, which we guess keeps the reciprocating weight down a bit and does let you directly compare bowden and direct drive print results on the same machine. Anyway, the first dual material prints came out pretty good after a few (quickly glossed over) fails, and did work well enough that dual-nylon printing could now be an option. After switching the build to a dual direct-drive setup, [Nathan] found it easier to get the machine to switch filaments more reliably, which makes sense when you think about the impact of all that extra filament in the bowden tube.

[Nathan] clearly has been burned (haven’t we all?) possibly literally, by the curious habit of some Chinese suppliers, of randomly assigning power supply polarity to red/black wire pairs. The solution, somewhat belt-and-braces, was to simply make up custom power cables with an embedded rectifier. Well, we guess that’s one less thing to worry about, but do look away when those PSU hacks are being shown!

Multi-material or multi-color FDM printer options are plenty, here’s a cool way of using a servo to swing a pair of hotends to the same point, and we also saw a while back, a way of using a sprung-loaded rocker to flip the unused hotend up out the way when not needed.

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Cool Mechanism Day: Two-Way To One-Way

March 14, 2022 by Dave Rowntree 8 Comments

The internal mechanisms that are used in timepieces have always been fascinating to watch, and are often works of art in their own right. You don’t have to live in the Watch Valley in Switzerland to appreciate this art form. The mechanism highlighted here (from Mechanistic on YouTube) is a two-way to one-way geared coupler (video, embedded below) which can be found at the drive spring winding end of a typical mechanical wristwatch. It is often attached to a heavily eccentrically mounted mass which drives the input gear in either direction, depending upon the motion of the wearer. Just a little regular movement is all that is needed to keep the spring nicely wound, so no forgetting to wind it in the morning hustle!

The idea is beautifully simple; A small sized input gear is driven by the mass, or winder, which drives a larger gear, the centre of which has a one-way clutch, which transmits the torque onwards to the output gear. The input side of the clutch also drives an identical unit, which picks up rotations in the opposite direct, and also drives the same larger output gear. So simple, and watching this super-sized device in operation really gives you an appreciation of how elegant such mechanisms are. Could it be useful in other applications? How about converting wind power to mechanically pump water in remote locations? Let us know your thoughts in the comments down below!

If you want to play with this yourselves, the source is downloadable from cults3d. Do check out some of the author’s other work!

We do like these super-sized mechanism demonstrators around here, like this 3D printed tourbillon, and here’s a little thing about the escapement mechanism that enables all this timekeeping with any accuracy.

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