Toy Inventor’s Notebook: Spin ’N Spill Balancing Bot game
By Caleb Kraft
Here’s a fun and easy action game: the Spin ’N Spill Balancing Bot. Stack the gears onto the tippy balancing robot — but be careful! If you cause him to drop or spill, you lose! This game is easy to make, especially if you have access to a laser cutter. […]
Check Out The Most Adorable Tiny Boiling Halloween Cauldron
By Caleb Kraft
Sometimes a collection of parts just comes together perfectly. I’m not sure what I find so captivating about this tiny cauldron from Adafruit, but it really struck me as fantastic. I’ve seen so many boiling cauldrons around Halloween, but the bluetooth connectivity and 3d prints being perfectly fit to a […]
Build A Peltier Coaster To Keep Your Coffee Warm — Or Cold
By Bill Gurstelle
A Cold junction In 1798, Jean Charles Athanase Peltier was just 13 years old and although he came from a poorly educated family in rural France, people already were beginning to notice the youngster’s intellectual talents. Besides being an avid reader of nearly any book he could get hold of, […]
Ring This Doorbell To Reveal A Spooky DIY Hologram
By Caleb Kraft
Paul from Litiholo wrote us to show off a little project they’re doing for Halloween. They’ve made this little spooky skeleton hologram in a casket that flashes to life when someone hits the doorbell. Look, we know that this is pretty much just an ad for their DIY hologram kits, […]
Build Your Own Thrust Vectored Rockets For Vertical Landings Like SpaceX
By Caleb Kraft
If you love rockets, you can’t help but notice that real space launch vehicles lift off the pad slowly,but model rockets zip up like darts. That’s how I became obsessed with using thrust vector control (TVC) — gimbaling the rocket motor — instead of fins to keep model rockets upright, […]
Registration For The Shenzhen Maker Summit Forum is Open
There are many reasons to visit Maker Faire Shenzhen. Some come to take a look at the innovative applications of technology by global makers, Some come to get involved and experience the fun of hands-on creation. Some come to learn about the highlights of science and technology and the crossover […]
Retro Hardware Plots Again Thanks to Grbl and ESP32
By Dan Maloney
When it comes to building a new CNC machine, you’ve got a wide world of controller boards to choose from. Whether you’re building a 3D-printer or a CNC plasma cutter, chances are good you’ll find a controller that fits your needs and your budget. Not so much, though, when you want to add CNC to a pen plotter from the early days of the PC revolution.
[Barton Dring] just posted the last installment of a five-part series in which he documented putting an Atari 1020 plotter under CNC control. The plotter was a peripheral for the Atari line of 6502 machines from the late 1970s; the guts of the little roll-fed, ballpoint-pen plotter appeared in Commodore, Tandy, and TI versions as well. [Bart]’s goal was to not add or modify anything to the mechanically simple device apart from the controller. That was easier said than done, given the unipolar stepper motors controlling the pen position and paper roll, and the fact that the pen lift mechanism uses a solenoid. Support for those had to be added to his Grbl_ESP32 firmware, as did dealing with the lack of homing switches in the plotter, and adapting the Grbl tool change command to the pen color change mechanism, which rotates the pen holder by bumping it into the right-hand carriage stop. The stock controller was replaced by a custom PCB that fits perfectly within the case, with plenty of room to spare. The video below shows it plotting out a vexillogically relevant sample.
The build is one that should be achievable by anyone with basic dressmaking skills. White and lavender tutus are combined to form the base of the skirt, with a lace outer layer sewn on to create an attractive silhouette for the lights. A USB battery pack is hidden in a pocket in the back to power the show. A WS2812B LED strip is then attached to the skirt, and hidden behind an additional layer of white faux-fur to help diffuse the light.
A pre-programmed LED controller from Cool Neon is used to run the strip, meaning no microcontroller code is required. It also allows the skirt’s lighting effects to be controlled by remote. Such controllers can make getting a glowable project up and running more quickly, particularly for those with less experience in the microcontroller space. Plus, the project can always be upgraded with a fancier controller later. For the most part, the vast majority of glowable projects use similar flashing and fading animations anyway; there’s really no need to reinvent the wheel every time.
[Mikaela] does a great job of showing the necessary steps to produce a skirt that is both attractive and functional. We’ve seen other great projects in this space before, too – like this awesome fibre optic piece. If you’re sewing up your own impressive glowable fashions, be sure to let us know! Video after the break.
Making a capacitor is pretty easy. Just get two conductors close together. The bigger area you can get and the closer you can get them, the bigger the capacitor you can make. [BigClive] found some fake capacitors that were supposed to be very high value, but weren’t. Taking them apart revealed the capacitors didn’t have the electrolyte inside that gives these units both their name and their high values. What did he do? Mixed up some electrolyte and filled them back up to see what would happen. You can see the video below.
Electrolytic capacitors have a secret weapon to get the two electrodes as close as possible to each other. The electrolyte forms a very thin insulating layer on one electrode and the capacitance is between the conductive fluid and that electrode — not between the two electrodes. This allows for a very narrow gap between the conductors and explains why a small electrolytic can have a much greater capacitance than most other technologies in similar form factors.
There are other tricks at play, too. For example, the anode side of the capacitor is usually etched or otherwise roughened to provide more surface area than a similar flat material. During manufacturing, a forming voltage causes the oxide layer to form and also sets a polarization on the capacitor. Reversing current through the device is likely to cause a short and quickly destroy the device.