Amplifier Controlled Motorized Display

It’s easy to get jaded by gadgets like the Chromecast or Sonos, which let the user control AV equipment remotely from a mobile device or computer. You can pick something to play from your phone and send it off to your speakers via the magic of Wi-Fi. But it’s still nice to have a display to look at for music visualizations and that sort of thing, at least occasionally.

To address this only occasional desire to have a display on your media setup, you could follow in the footsteps of [Steven Elliott] and create a DIY motorized display which only pops up when needed. Inspired by seeing videos of TVs rising out of cabinets and other such trickery, he decided to create his own version using an old computer monitor he had lying around.

The monitor is lifted with a beefy linear actuator, which has been placed inside of a square metal fence post to keep from rotating. It already had a power supply and control board with relays for extending and retracting, so [Steven] just needed to find a convenient way of firing them off.

The answer came from a somewhat unconventional source: his amplifier. [Steven] explains that many amplifiers feature a “Trigger Output”, which uses a standard stereo 3.5mm connector and sends a 12V pulse to connected device. This is generally used to turn on downstream devices when the amplifier switches to the respective input. It’s too short and not nearly powerful enough to close the actuators relays, but it’s easy enough to detect.

[Steven] uses a LeoStick microcontroller to wait for the pulse from the amplifier, and then use that to raise or lower the display depending on the selected input. There’s also a SPST momentary switch which can be used to trigger the actuator manually. Beyond the fact the linear actuator is a bit loud, he says the setup works very well and prevents him from having to start up his projector if he just wants to take a quick glance at what’s playing or program his DVR.

We don’t see many motorized display lifts like this anymore, not since wall mounted LCDs became popular anyway. But it’s still a cool effect, and today made quite a bit easier thanks to the fact that TVs and monitors no longer weigh as much as a small car.

[Thanks to Baldpower for the tip.]

A DIY Balcony Crane Lifts Groceries For The Lazy But Patient

If necessity is the mother of invention, then laziness is probably its father. Or at least a close uncle. Who hasn’t thought, “There has to be a better way to do this, one that doesn’t involve me burning precious calories”?

Motivational laziness seems to increase with potential energy, as anyone who needs to haul groceries up four flights of stairs will tell you. This appears to be where this balcony-mounted drill-powered crane came from. Starting with a surplus right-angle gearbox and drum, [geniusz K] fabricated the rest of the crane from steel plate and tubing. We like the quality of fabrication and the tip on making slip couplings from bits of square tubing. The finished product got a nice coat of brown paint to match the balcony railing; keeping the neighbors happy is always important. He tested the crane with a 20-kg weight before installing it on the balcony and put it to work hauling groceries up three stories. Check out the build and the test in the video below.

While it won’t set any speed records, at least the drill is doing the work. But what if you’re impatient as well as lazy? Aside from being two-thirds of the way to programming greatness, you may have to up the game. A heavy-lift quadcopter, perhaps?

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Fishing For AirPods With Magnets

Note to self: if you’re going to hack at 4 in the morning, have a plan to deal with the inevitable foul ups. Like being able to whip up an impromptu electromagnetic crane to retrieve an AirPod dropped out a window.

Apartment dweller [Tyler Efird]’s tale of woe began with a wee-hours 3D print in need of sanding. Leaning out his third-story window to blow off some dust, he knocked one AirPod free and gravity did the rest. With little light to search by and a flight to catch, the wayward AirPod sat at the bottom of a 10-foot shaft below his window, keeping company with a squad of spiders for two weeks. Unwilling to fork over $69 and wait a month and a half for a replacement, [Tyler] set about building a recovery device. A little magnet wire wound onto a bolt, a trashed 100-foot long Ethernet cable, and a DC bench supply were all he needed to eventually fish up the AirPod. And no spiders were harmed in the making of this hack.

Need to lift something a little heavier than an AirPod? A beefy microwave oven transformer electromagnet might be the thing for you. And confused about how magnets even work in the first place? Check out our primer on magnetism.

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LiftLocker Keeps Your Lift Safe From Attacking Garage Doors

Car lifts used to be a tool reserved for professional mechanics. Times are a-changing though. With the advent of reasonably priced four-post hydraulic lifts, more and more shade tree mechanics are joining the five-foot high club. Installing a lift in a home garage creates a few hazards, though. What happens when a family remotely opens the garage door while there is a car up on the lift? Garage door and lifted vehicle will meet – with expensive and/or dangerous results. [Joe Auman] saw this problem coming a mile away. He built the LiftLocker to make sure it never happens to him.

At its core, LiftLocker is a set of switched extension cords. Two cast-aluminum boxes hide the electronics. One box plugs in-line with the lift. The other box plugs in-line with the garage door opener. Each box includes a Sparkfun Redboard Arduino compatible, an RFM22 433 MHz Radio, and a relay. Input comes from a security system magnetic reed-switch. Both boxes are identical in hardware and code.

Operation is simple. One box and reed switch goes on the lift, the other on the garage door. If the lift is going up, its reed switch will open. The lift’s Arduino detects this and commands its RFM22 to send a signal to the other box on the garage door. Upon receiving this signal, the garage door controller will open its relay, disconnecting power to the garage door opener. Communication is two-way, so if the Lift controller doesn’t hear an ACK message from the garage door controller, everything will shut down. Click past the break to see the system in action.

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Heavy Lift Electromagnet From Microwave Oven Transformers

It’s OK, you can admit it — from the time you first saw those huge electromagnetic cranes in scrap yards you’ve wanted to have one. While it may not fling around a car, parts donated from scrapped microwaves can let you build your own electromagnetic lifting device and make that dream finally come true.

We recently watched [MakeItExtreme] turn a couple of microwave oven transformers into a somewhat ill-advised wall-climbing rig. It looks like that may have been the inspiration for this build, and the finished product appears to be a tad more useful this time. The frames of three MOTs are cut open to remove the secondary coils and leave the cores exposed as poles for the future magnets. A shallow dish is fabricated out of steel and the magnets are welded in place.

With the primaries wired together, the magnets are epoxy potted, the business end is faced off cleanly, and the whole thing put to the test. [MakeItExtreme] doesn’t go into control details in the video below, but the website mentions the magnet being powered off a 24V 15A power supply with battery backup in case of mains failure.

They’ve lifted 200kg so far, and it looks like a pretty cool addition to a shop already packed with other builds, like their MOT spot welder and a propane tank sandblaster.

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Scissor Lift Shoes May Be OSHA Compliant

It’s been said that necessity is the mother of all invention. This was probably the fundamental principle behind the show “Inspector Gadget”, a story about a police agent who has literally any technology at his grasp whenever he needs it. Although the Inspector’s gadgets get him into trouble more often than not (his niece Penny usually solves the actual crimes), the Inspector-inspired shoes that [Make it Extreme] built are a little bit more useful than whatever the Inspector happens to have up his sleeve (or pant leg, as the case may be).

If a fabrication tour de force, [Make it Extreme] built their own “Go Go Gadget Legs”, a set of pneumatically controlled stilts that allow the wearer to increase their height significantly at the push of a button. We often see drywall contractors wearing stilts of a similar height, but haven’t seen any that are able to raise and lower the wearer at will. The team built the legs from scratch, machining almost every component (including the air pistons) from stock metal. After some controls were added and some testing was done, the team found that raising one foot at a time was the safer route, although both can be raised for a more impressive-looking demonstration that is likely to throw the wearer off balance.

The quality of this build and the polish of the final product are incredibly high. If you have your own machine shop at home this sort of project might be within your reach (pun intended). If all you have on hand is a welder, though, you might be able to put together one of [Make it Extreme]’s other famous builds: a beer gun.

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We Recommend That You Enter A Cyclocopter From The Front

It’s crazy to think that we’ve optimized the heck out of some types of powered flight when there are entire theories and methods that haven’t even seen many government research dollars, let alone the light of day. The cyclocopter is apparently one of those. It was dreamt up around the same time as a helicopter, but was too audacious for the material science of the time. We have helicopters, but [Professor Moble Benedict] and his graduate students, [Carl Runco] and [David Coleman], hope to bring cyclocopters to reality soon.

For obvious reasons they remind us of cyclocranes, as the wings rotate around their global axis, they also rotate back and forth in a cycloidal pattern around their local axis. By changing this pattern a little bit, the cyclocopter can generate a wide variety of thrust vectors, and, hopefully, zip around all over the place. Of course, just as a helicopter needs a prop perpendicular to its main rotor on its tail to keep if from spinning around its axis, the cyclocopter needs a prop facing upwards on its tail.

It does have a small problem though. The bending force on its wings are so strong that they tend to want to snap and fly off in all different directions. Fortunately in the past hundred years we’ve gotten ridiculously good at certain kinds of material science. Especially when it comes to composites we might actually be able to build blades for these things. If we can do that, then the sky’s the limit.

[Professor Benedict] and his team are starting small. Very small. Their first copter weighs in under 30 grams. It took them two years of research to build. It will hopefully lead to bigger and bigger cyclocopters until, perhaps, we can even build one a person can get into, and get out of again.