Kids Kitchen That Says BEEP

Children have always liked to learn by copying the adults around them, and thus have always desired toys that emulate the tools which their older forebears use on a daily basis. [rhoalt]’s daughter wished for an oven to play with, so a trip to IKEA was in order to get started.

The build begins with the IKEA Duktig, a beautiful fun-sized oven. [rhoalt] then breaks out the hacker staple foods of 7-segment displays, swanky backlit buttons and an Arduino Nano. Through some careful handiwork, the wooden panels that make up the toy oven are drilled and routed out to fit the components.

The electronics are all used to create an oven with a digital timer, and the final effect achieved is rather nice. The glowy buttons can be used to set and reset the timer, while an LED strip inside lights up to simulate cooking. [rhoalt] shares all the construction details along with some parent-friendly tips, like taping over the buzzer to reduce the volume, and ensuring the timer is limited to 10 minutes to avoid any late-night surprises.

It’s a tidy project with a strong sense of fun, and the presentation is top-notch. Even we older, jaded hackers light up for a good glowy-buttoned project, so we’re sure [rhoalt]’s daughter loves her new toy. For more toy oven action, check out this Easy Bake converted to USB. Video after the break.

Continue reading “Kids Kitchen That Says BEEP”

Fingerling Disemboweled For Your Entertainment

Due to the graphic nature of this post, small children and the elderly may want to leave the room. One of the hottest toys this holiday season has been gutted like a fish so that we may better understand the nature of its existence. Or maybe just what kind of sensors and motors the craftsmen over at WowWee managed to cram into a “robot” with an MSRP of only $15 USD.

[Josh Levine] mercilessly tears a Fingerling Monkey limb from limb on his blog, and points out some interesting design decisions made. While some elements of the toy are rather clever, there’s a few head-scratchers to be had inside the Fingerling. It’s interesting to see the final results of a decision process that had to balance the relatively rough life such a toy will live with the ever crucial cost of production.

The eyelids are particularly well thought out, operated by charging a coil under a magnet which is embedded in the plastic. Opening and closing the eyelids without a separate motor or gearbox is not only easier and cheaper, but prevents the possibility of damage if a child attempts to force open the eyes or otherwise manipulate the mechanism.

Other cost saving measures include the use of foil tape as a capacitive sensor, and simple ball-filled tilt sensors to detect orientation rather than an expensive accelerometer.

Interestingly, other parts of the toy seem overengineered in comparison. A cam and limit switch are used to detect when the Fingerling’s head has turned to its maximum angle, when it would have been cheaper and easier to simply detect motor stall current.

If you’re interested in seeing what makes popular toys tick, we’ve got a number of plaything tear downs which are sure to keep you satiated until the next big holiday toy rolls around.

Continue reading “Fingerling Disemboweled For Your Entertainment”

Restoring A Tonka Truck With Science

The yellow Tonka Truck. Instantly recognizable by any child of decades past, that big metal beast would always make you popular around the sandbox. There were no blinking lights to dazzle, no noises to be heard (unless you count the hard plastic wheels rolling on concrete), even the dumping action is completely manual. But back then, it was a possession to be treasured indeed.

So it’s perhaps no surprise that there is a certain following for these classic trucks today, though like with most other collectibles, a specimen in good condition can be prohibitively expensive. The truck that [PoppaFixIt] found in the trash was certainly not one of those specimens, but with some patience and knowledge of basic chemistry, he was able to bring this vintage toy back to the present.

The first step was to disassemble the truck. Before they switched over to Chinese mass production, these trucks were built with actual rivets. After drilling them out and unfolding the little metal tabs that toy makers loved back in the day, he was able to separate the metal body of the truck from the plastic detail bits. The plastic parts just needed a fresh coat of paint, but the rusted metal body would need a bit more attention.

Remembering a tip he read online, [PoppaFixIt] decided to attempt electrolytic rust removal to get the metal parts back into serviceable condition. A big plastic bin, some washing soda, and old steel window weights for his sacrificial anodes was all the equipment he needed for the electrolysis tank. To power the chemical reaction he used a standard 12 volt car battery and charger wired in parallel; this step is important, as he notes most newer chargers are smart enough not to work unless they see a real battery connected.

After running the setup overnight, the collected rust and junk on the window weights was proof enough the process worked. From there, it was just a fresh coat of yellow paint, a new sticker kit from eBay, and his Tonka truck was ready to face another 30+ years of service.

If you’re looking to restore things larger than a child’s toy, you may be interested in the much larger electrolytic setup we’ve covered previously. Of course if you’re really pressed for time, you could try blasting the rust away with a laser.

Cheap RC Truck Mod Is Slightly Risky Fun

The world of RC can be neatly split into two separate groups: models and toys. The RC models are generally big, complex, and as you’d imagine, more expensive. On the other hand, the RC toys are cheap and readily available. While not as powerful or capable as their more expensive siblings, they can often be a lot of fun; especially since the lower costs means a crash doesn’t put too big of a ding into to your wallet.

With his latest mod, [PoppaFixIt] has attempted to bridge the gap between toy and model by sticking a considerably overpowered battery into a $10 RC truck from Amazon. He reports greatly improved performance from his hacked together truck, but anyone looking to replicate his work should understand the risks before attempting to hack up their own version.

The principle is pretty simple; the truck is designed to run on two AA batteries, providing 3 volts. But by swapping the AAs out for a 3.7 volt 1S LiPo of the type that’s used in small airplanes and quadcopters, you can get an instant boost in power. As a happy side effect, the LiPo batteries are also rechargeable and fairly cheap, so you won’t have to keep burning through alkaline AAs.


The mod itself is a basic job that only requires a few bucks in parts, and for which [PoppaFixIt] has helpfully provided Amazon links. Essentially you just crack open the truck, solder a JST connector pigtail to the positive and negative traces on the PCB, and then pop a hole in the roof to run the new battery wires out.

Right about now the RC purists are probably screaming obscenities at their displays, and not without reason. As fun as these supercharged little trucks are to drive, there are a number of real issues here which need to be mentioned.

First, while the motor will probably be alright with a bit higher voltage running through them, the gears won’t be liking it one bit. In fact, [PoppaFixIt] even mentions they shredded a few gears when they tried to take one off-road. The second issue is that since these vehicles were not designed with LiPo batteries in mind, there’s no low voltage cutoff to prevent over discharge. If you aren’t careful, a setup like this will cook those cute little batteries in short order. But hey, at least it’s all cheap.

If you are more interested in control than power, you may want to check out the previous hacks we’ve featured. Seems like these little RC trucks are the platform of choice for hackers who want to get stuff moving on the cheap.

Becdot Teaches With Touch

Braille is a tactile system of communication, used the world over by those with vision impairment. Like any form of language or writing, it can be difficult to teach and learn. To help solve this, [memoriesforbecca] has developed Becdot as a teaching tool to help children learn Braille.

The device is built around four Braille cells, which were custom-designed for the project. The key was to create a device which could recreate tactile Braille characters at low cost, to enable the device to be cheap enough to be used a children’s toy. The Braille cells are combined with an NFC tag reader. Small objects are given NFC tags which are programmed into the Becdot. When the object is placed onto the reader, the Braille cells spell out the name of the object. Objects can be tagged and the system programmed with a smartphone, so new objects can be added by the end user.

It’s a great way to teach Braille, and an impressive build that keeps costs down low. Details are a little thin on the ground, and we’d love to see more detail on how the actuators on the Braille cells work. We’ve seen similar projects before, like this Hackaday prize entry. Share your theories in the comments below.

Spice Up Your Bench With 3D Printed Dancing Springs

Not all projects are made equal. Some are designed to solve a problem while others are just for fun. Entering the ranks of the most useless machines is a project by [Vladimir Mariano] who created the 3D Printed Dancing Springs. It is a step up from 3D printing a custom slinky and will make a fine edition to any maker bench.

The project uses 3D printed coils made of transparent material that is mounted atop geared platforms and attached to a fixed frame. The gears are driven by a servo motor. The motor rotates the gears and the result is a distortion in the spring. This distortion is what the dancing is all about. To add to the effect, [Vladimir Mariano] uses RGB LEDs controlled by an ATmega32u4.

You can’t dance without music. So [Vladimir] added a MEMs microphone to pick up noise levels which are used to control the servo and lights. The code, STL files and build instructions are available on the website for you to follow along. If lights and sound are your things, you must check out the LED Illuminated Isomorphic Keyboard from the past. Continue reading “Spice Up Your Bench With 3D Printed Dancing Springs”

How To MIDI Interface Your Toys

There’s a great number toys in the world, many of which make all manner of pleasant or annoying noises for the entertainment of children. If you’re a musician, these toys may be of interest due to their unique or interesting sounds. However, due to their design being aimed at play rather than performance, it may be difficult to actually use the toy as a musical instrument. One way around this is to record the sounds of the toy into a sampler, but it’s not the only way. [little-scale] is here to demonstrate how to MIDI interface your toys. 

[little-scale] starts out by discussing the many ways in which one can interface with a toy. The article discusses how a simple button can be replaced with a relay, or a multiplexer, and be interfaced to all manner of other devices to control the toy. This is demonstrated by using a mobile phone toy which makes sounds when buttons are pressed.

A Teensy 3.6 is used to run the show, acting as a USB-MIDI interface so the toy can be controlled by music software like Abelton. It’s connected to the toy’s buttons through a multiplexer. The toy’s speaker is cut off and used as an audio output instead, allowing the toy to be easily connected to other audio hardware for performance or recording. It’s also fed through a digital pot so MIDI commands can control the volume. A resistor is used to control pitch in the toy, so this too was replaced with a digital pot as well, to allow sample pitch to be controlled.

The project is incredibly well documented, with [little-scale] first tearing down the toy and highlighting the points of interest, before stepping through each stage of interfacing the toy to the digital world. We’ve seen some of [little-scale]’s work before, too – namely, this MIDI DAC for controlling vintage synthesizers. Video after the break. Continue reading “How To MIDI Interface Your Toys”