Author Archives: Donald Papp

Rushing the Design and Construction of LED Centerpieces

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Sometimes the most important thing is getting something done.

[Alex Lao] was recently in such a situation. His sister was getting married and he designed, built, and delivered twenty RGB LED table centerpieces in a rush. There were no prototypes made, and when the parts arrived all twenty were built all at once over a single weekend. These table centerpieces are illuminated by RGB LEDs and battery-powered, but have an option to be powered by a wall adapter.

[Alex] helpfully shared some tips on reducing the production risks and helping ensure results in such a limited time frame. His advice …read more

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3D Printing Flexible Surfaces out of Non-Flexible Material

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Here’s some interesting work shared by [Ben Kromhout] and [Lukas Lambrichts] on making flexible 3D prints, but not by using flexible filament. After seeing a project where a sheet of plywood was rendered pliable by cutting a pattern out of it – essentially turning the material into a giant kerf bend – they got interested in whether one could 3D print such a thing directly.

The original project used plywood and a laser cutter and went through many iterations before settling on a rectangular spiral pattern. The results were striking, but the details regarding why the chosen pattern was best …read more

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3D Printing Flexible Surfaces out of Non-Flexible Material

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Here’s some interesting work shared by [Ben Kromhout] and [Lukas Lambrichts] on making flexible 3D prints, but not by using flexible filament. After seeing a project where a sheet of plywood was rendered pliable by cutting a pattern out of it – essentially turning the material into a giant kerf bend – they got interested in whether one could 3D print such a thing directly.

The original project used plywood and a laser cutter and went through many iterations before settling on a rectangular spiral pattern. The results were striking, but the details regarding why the chosen pattern was best …read more

Continue reading 3D Printing Flexible Surfaces out of Non-Flexible Material→

Edge-lit Pendants Show Two Layers are Better Than One

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Engraved acrylic lights up nicely with LED lighting. Simply engrave clear acrylic with a laser engraver, then edge-light the acrylic and watch the engraving light up. This badge made by [Solarbotics] shows how they used this principle when creating some pendants for an event that performed particularly well in the dark.

The pendants they created have two engraved acrylic panels each, and that’s about it. Two LEDs and a CR2032 battery nestle into pre-cut holes, and the engraved sides are placed face-to-face, so the outer surfaces of the pendant are smooth. By using some color-cycling RGB LEDs on one panel …read more

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This Method of Gluing onto Curves Sucks!

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Sometimes the right tool for a job can be unusual, and this sucked only in the sense that vacuum sealing was involved. Recently [Martin Raynsford] found himself in a situation of needing to glue a wood veneer onto a curved surface, but faced a shortage of clamps. His clever solution was to vacuum-seal the whole thing and let the contour-hugging plastic bag take care of putting even pressure across the entire glued surface. After the glue had set enough to grip the materials securely, the bag was removed to let the whole thing dry completely. Gluing onto a curved surface …read more

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DIY Illuminator for UV Fluorescence Photography

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The image shown is the mineral Hackmanite, which fluoresces under ultraviolet lighting. However, not all UV is created equal, and that makes a difference if you’re into UV imaging. The image for this article is from [David Prutchi] and shows the striking results of using different wavelengths of UV. [David] goes into detail on how to make your own DIY Long, Medium, and Short-wave UV Illuminator complete with part numbers and wiring diagram. The device isn’t particularly complicated; the real work was determining the exact part numbers and models of lamp, filters, and ballasts required to get the correct results. …read more

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SCiO “Pocket Molecular Scanner” Teardown

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Some of you may remember the SCiO, originally a Kickstarter darling back in 2014 that promised people a pocket-sized micro spectrometer. It was claimed to be able to scan and determine the composition of everything from fruits and produce to your own body. The road from successful crowdsourcing to production was uncertain and never free from skepticism regarding the promised capabilities, but the folks at [Sparkfun] obtained a unit and promptly decided to tear it down to see what was inside, and share what they found.

The main feature inside the SCiO is the optical sensor, which consists of …read more

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Microorganisms Can’t Hide From DropoScope

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The DropoScope is a water-drop projector that works by projecting a laser through a drop of water, ideally dirty water crawling with microorganisms. With the right adjustments, a bright spot of light is projected onto a nearby wall, revealing a magnified image of the tiny animals within. Single celled organisms show up only as dark spots, but larger creatures like mosquito larvae exhibit definite structure and detail.

While simple in concept and requiring nothing more high-tech than a syringe and a laser pointer, getting useful results can require a lot of fiddly adjustment. But all that is a thing of …read more

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Reflective Sensor Becomes Kart Racing Lap Counter

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Once you have a track and a kart to race on it, what’s missing? A lap counter that can give your lap times in hardcopy, obviously! That’s what led [the_anykey] to create the Arduino-based Lap Timer to help him and his kids trim those precious seconds off their runs, complete with thermal printer for the results.

The hardware uses an infrared break-beam sensor module (a Velleman PEM10D) to detect when a kart passes by. This module is similar to a scaled-up IR reflective object sensor; it combines an IR emitter and receiver on one end, and is pointed at a …read more

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Hackaday Prize Entry: PCBs On Demand with Etchr

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The ambitious etchr – the PCB Printer is just a concept at the moment, but it’s not often we see someone trying to tackle desktop PCB production in a new way. Creator [Jonathan Beri] is keenly aware that when it comes to creating electronics, the bottleneck for most workflows is the PCB itself. Services like OSH Park make professionally fabricated PCBs accessible at a low cost, but part of the bargain is that turnaround times are often measured in weeks.

[Jonathan]’s concept for etchr is a small system that automates not only etching a copper-clad board with all the attendant …read more

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