First Person View (or First Person Video) in RC refers to piloting a remote-controlled vehicle or aircraft via a video link, and while serious racers will mount the camera in whatever way offers the best advantage, it’s always fun to mount the camera where a miniature pilot’s head would be, and therefore obtain a more immersive view of the action. [SupermotoXL] is clearly a fan of this approach, and shared downloadable designs for 3D printed cockpit kits for a few models of RC cars, including a more generic assembly for use with other vehicles. The models provide a dash, steering wheel, and even allow for using a small servo to make the steering wheel’s motions match the actual control signals sent. The whole effect is improved further by adding another servo to allow the viewer to pan the camera around.
Check out the video embedded below to see it in action. There are more videos on the project’s page, and check out the project’s photo gallery for more detailed images of the builds.
[Ben] made an interesting discovery during the FIFA World Cup in 2018, and used it to grant himself the power to call goals before they happened. Well, before they happened on live TV or live streaming, anyway. It was possible because of the broadcast delay on “live” broadcasts, combined with the sports betting industry’s need for timely and detailed game state tracking.
He discovered that a company named Running Ball provides fairly detailed game statistics in digital form, which are generated from inside the stadium as events occur. An obvious consumer of this data are sports betting services, and [Ben] found a UK betting site that exposed that information in full inside their web app. By polling this data, he measured a minimum of 4 seconds between an event (such as a goal) being reported in the data and the event occurring on live TV. The delay was much higher — up to minutes — for live streaming. [Ben] found it quite interesting to measure how the broadcast delay on otherwise “live” events could sometimes be quite significant.
Knowing broadcast delays exist is one thing, but it’s a neat trick to use it to predict goals before they occur on “live” television. This isn’t the first time we’ve seen evidence of [Ben]’s special interest in data and using it in unusual ways; he once set up a program to play Battleship over the Border Gateway Protocol (BGP), making it very probably the first board game played over BGP.
The cannon has a rotary barrel driven by a small motor, and a clever sear design uses the rotation of the barrels like a worm gear. The rotating barrel has a spiral formation of hooks which anchor the stretched elastic bands. A small ramp rides that spiral gap, lifting ends of stretched bands one at a time as the assembly turns. This movement (and therefore the firing control) is done with a small continuous rotation servo. While in theory any motor would do, using a servo has the advantage of being a standardized shape, and therefore easy to integrate into the design. A video is embedded below in which you can see it work, along with some close-ups of the action.
Pivots for e-textiles can seem like a trivial problem. After all, wires and fabrics bend and flex just fine. However, things that are worn on a body can have trickier needs. Snap connectors are the usual way to get both an electrical connection and a pivot point, but they provide only a single conductor. When [KOBAKANT] had a need for a pivoting connection with three electrical conductors, they came up with a design that did exactly that by using a flexible circuit board integrated to a single button snap.
This interesting design is part of a solution to a specific requirement, which is to accurately measure hand movements. The photo shows two strips connected together, which pivot as one. The metal disk near the center is a magnet, and underneath it is a Hall effect sensor. When the wrist bends, the magnet is moved nearer or further from the sensor and the unit flexes and pivots smoothly in response. The brief videos embedded below make it clear how the whole thing works.
[Black Beard Projects] sealed some pine cones in colored resin, then cut them in half and polished them up. The results look great, but what’s really good about this project is that it clearly demonstrates the necessary steps and techniques from beginning to end. He even employs some homemade equipment, to boot.
Briefly, the process is to first bake the pine cones to remove any moisture. Then they get coated in a heat-activated resin for stabilizing, which is a process that infuses and pre-seals the pine cones for better casting results. The prepped pine cones go into molds, clear resin is mixed with coloring and poured in. The resin cures inside a pressure chamber, which helps ensure that it gets into every nook and cranny while also causing any small air bubbles introduced during mixing and pouring to shrink so small that they can’t really be seen. After that is cutting, then sanding and polishing. It’s an excellent overview of the entire process.
The video (which is embedded below) also has an outstanding depth of information in the details section. Not only is there an overview of the process and links to related information, but there’s a complete time-coded index to every action taken in the entire video. Now that’s some attention to detail.
[Mark Rehorst] has been busy designing and building 3D printers, and Son of Megamax — one of his earlier builds — needed a bed heater replacement. He took the opportunity to add a Kelvin-type kinematic mount as well. The kinematic mount and base efficiently constrain the bed in a controlled way while allowing for thermal expansion, providing a stable platform that also allows for removal and repeatable re-positioning.
After a short discussion regarding the heater replacement, [Mark] explains the design and manufacture of his kinematic mount. Of particular note are the practical considerations of the design; [Mark] aimed to use square aluminum tubing as much as possible, with machining requirements that were easily done with the equipment he had available. Time is a resource after all, and design decisions that help one get something working quickly have a value all their own.
If you’re still a bit foggy on kinematic mounts and how they work, you’re not alone. Check out our coverage of this 3D-printed kinematic camera mount which should make the concept a bit clearer.
Drone racing is nifty as heck, and a need all races share is a way to track lap times. One way to do it is to use transponders attached to each racer, and use a receiver unit of some kind to clock them as they pass by. People have rolled their own transponder designs with some success, but the next step is ditching add-on transponders entirely, and that’s exactly what the Delta 5 Race Timer project does.
The open-sourced design has a clever approach. In drone racing, each aircraft is remotely piloted over a wireless video link. Since every drone in a race already requires a video transmitter and its own channel on which to broadcast, the idea is to use the video signal as the transponder. As a result, no external hardware needs to be added to the aircraft. The tradeoff is that using the video signal in this way is trickier than a purpose-made transponder, but the hardware to do it is economical, accessible, and the design is well documented on GitHub.
The hardware consists of RX508 RX5808 video receiver PCBs modified slightly to enable them to communicate over SPI. Each RX508 RX5808 is attached to its own Arduino, which takes care of low-level communications. The Arduinos are themselves connected to a Raspberry Pi over I2C, allowing the Pi high-level control over the receivers while it serves up a web-enabled user interface. As a bonus, the Pi can do much more than simply act as a fancy stopwatch. The races themselves can be entirely organized and run through the web interface. The system is useful enough that other projects using its framework have popped up, such as the RotorHazard project by [PropWashed] which uses the same hardware design.
While rolling one’s own transponders is a good solution for getting your race on, using the video transmission signal to avoid transponders entirely is super clever. The fact that it can be done with inexpensive, off the shelf hardware is just icing on the cake.