[Zaprodk] had trash-picked a defunct HP Envy 450 AIO, a 3-in-1 printer, scanner, and copier. Normally there usually isn’t much use for these unless you’re willing to hunt down the cartridges which it used, so your next step is to dismantle it for parts. That’s what he was going to do but then decided to see if he could remove as much as possible while leaving just the scanner.
He ran into trouble after he’d “fixed” the lid-open sensor and unplugged pretty much everything. He was getting too many error messages on the LCD panel to reconfigure the WiFi. Luckily he could connect it to his computer using USB and do the configuration from there. One dubious mod involved turning an “unflipped” flexible flat cable into a “flipped” one by doing a little cutting, scraping and gluing. Check out his write-up for the full hack.
Rockets with nuclear bombs for propulsion sounds like a Wile E. Coyote cartoon, but it has been seriously considered as an option for the space program. Chemical rockets combust a fuel with an oxidizer within themselves and exhaust the result out the back, causing the rocket to move in the opposite direction. What if instead, you used the higher energy density of nuclear fission by detonating nuclear bombs?
Detonating the bombs within a combustion chamber would destroy the vehicle so instead you’d do so from outside and behind. Each bomb would include a little propellant which would be thrown as plasma against the back of the vehicle, giving it a brief, but powerful push.
That’s just what a group of top physicists and engineers at General Atomic worked on between 1958 and 1965 under the name, Project Orion. They came close to doing nuclear testing a few times and did have success with smaller tests, exploding a series of chemical bombs which pushed a 270-pound craft up 185 feet as you’ll see below.
His write-up is a pretty fun read, walking through his process, including an oscilloscope measurement showing how the capacitors’ voltage drops from 5.26 V to 3.5 V when the trigger is pressed, and interestingly, slowly recovers until it’s released a second later, when it then rises back to 4.5 V. He’s even included how he worked out of the panel’s maximum power point (MPP), which is what he was doing when the kids were first lured away to blow soap bubbles. But we’re sure Hackaday readers aren’t as easily distracted.
The resulting Solar Powered Bubble Blaster works quite well. At a starting voltage of 5.23 V, it runs for 15 seconds and then takes only a minute to recharge. Charged batteries would have had a longer runtime but take longer to recharge, an important point when trying to keep kids interested. See it in action in the video below.
This Bluetooth speaker is full of delightful surprises. The outer shell is an antique radio cabinet, but its practically empty interior is a combination of Dead Bug circuitry and modern BT receiver.
[PJ Allen] found the BT receiver on Groupon and decided to whip up amplifier and threshold detector circuits using only parts he already had in order to make this vintage-looking Bluetooth speaker. The cabinet is from a Silvertone Model 1955 circa 1936. Don’t worry, no antiques were harmed in the making of this hack, the cabinet was empty when he bought it.
The amplifiers, one per speaker, began life as a circuit from TI’s LM4871 datasheet. Some of the departures came about because he didn’t have the exact component values, even paralleling capacitors to get in the right range. The finished board is a delightful mix of “Dead Bug” and quasi-Manhattan style construction, “quasi” because he carved up the ground plane instead of laying pads on top of it.
Look at the front of the cabinet and you’ll see a rectangular display. Watch the video below and you’ll see that it throbs in time to the music. To do that he came up with a threshold detector circuit which started out based on a circuit from a Sharp/Optonica cassette tape deck, but to which he made improvements.
A Tile is a small Bluetooth device which you can put on your keychain, for example, so that you can find your keys using an app on your phone. Each Tile’s battery life expectancy is one year and after that year you’re expected to trade it in at a discount for a new one. Right away your hacker senses are tingling and you know what’s coming.
[Luis Rodriguez] had switched to Samsung SmartThings and had accumulated box of these Tiles with dead batteries. So he decided a fun project would be to put a Tile in his wife’s car to track it. Given that it’s using Bluetooth, the range isn’t great for car tracking, but the Tile’s app can network with other user’s apps to widen the search area.
Since the Tile’s battery was dead, he cracked it open and soldered wires to its power terminals. He then found a handy 12 volt source in the car and added a DC to DC buck converter to step the voltage down to the Tile’s 3 volts. Finding a home for the hacked tracker was no problem for [Luis]. He was already using an ODB-II dongle for a dash cam so he tapped into the 12 V rail on that.
You’ll be surprised what you can find by hacking these small tracking devices. Here’s an example of hacking of a fitness tracker with all sorts of goodies inside.
Our thanks to [Maave] for tipping us off about this hack.
The last chapter of the fourth book of the Hitch-Hiker’s Guide to the Galaxy trilogy mentions two hacks that made life pleasant enough to prevent a war: a super-fly that could fly out of the open half of a half-open window, and an off-switch for children. This is one of those types of hacks. Plus, it’s just an awesome idea, fun to watch, and possibly adaptable for the workshop.
After the kids have gone to bed and LEGO bricks are scattered all over the floor, furniture, stairs (ouch), and everywhere else, wouldn’t it be nice if you could simply vacuum it all up directly into the LEGO box? This ingenious hack from [The King or Random] YouTube channel shows how to just that. They put two holes in opposite corners of the box’s lid, one a tight fit for a flexible intake hose and the other for the Shopvac hose, or a normal household vacuum cleaner hose if you prefer. A disk cut from flyscreen covers the Shopvac hole in case the suction is strong enough to pull the bricks back out of the box and into the Shopvac. They also make a gasket for the lid by mixing up some silicone sealant and cornstarch, the cornstarch is to prevent the cured mix from remaining sticky. We of course really like the version they made which has a window in the side of the box for watching the bricks as they fly in. Check out their build and the action in the video below.
We wonder what other uses this can be put to. How about a container for sucking up a mess of loose hardware from a workbench or a garage floor for later sorting?
Lip syncing for computer animated characters has long been simplified. You draw a set of lip shapes for vowels and other sounds your character makes and let the computer interpolate how to go from one shape to the next. But with physical, real world puppets, all those movements have to be done manually, frame-by-frame. Or do they?
He toyed around with a number of approaches for making the lip mechanism before coming up with one that worked the way he wanted. The lips are shaped using guitar wire soldered to other wires going to servos further back in the head. Altogether there are four servos for the lips and one more for the jaw. There isn’t much sideways movement but it does enough and lets the brain fill in the rest.
On the software side, he borrows heavily from the tools used for lip syncing computer-drawn characters. He created virtual versions of the five servo motors in Adobe Animate and manipulates them to define the different lip shapes. Animate then does the interpolation between the different shapes, producing the servo positions needed for each frame. He uses an AS3 script to send those positions off to an Arduino. An Arduino sketch then uses the Firmata library to receive the positions and move the servos. The result is entirely convincing as you can see in the trailer below. We’ve also included a video which summarizes the iterations he went through to get to the finished Billy Whiskers or just check out his detailed website.