[Simon] started this project with a goal of driving on water. Initial experiments were promising – the first design of paddle tyres gave great traction in the sand and were capable of climbing some impressive slopes. However, once aimed at the water, the car quickly sank below the surface.
Returning to the drawing board armed with the advice of commenters, [Simon] made some changes. The paddle tyres were reprinted with larger paddles, and a more powerful R/C car selected as the test bed. On the second attempt, the car deftly skipped along the surface and was remarkably controllable as well! [Simon] has provided the files so you can make your own at home.
The car in question is a Hobbyking Desert Fox RC car – normally a four-wheel drive truck which ships ready-to-run, making it a great way to get a project started quickly. Rocket power is provided by the same type of motor used in the Swedish Rocket Knives we’ve covered previously.
Initial testing proves unsuccessful – the car simply tumbles out of control when the rocket is fired. It takes a beating, losing a wheel in the process. Following on from this, a decision is made to cook up a slower burning rocket motor and switch to an asphalt surface for testing. This is much more succesful and the car begins to see some properly high speeds, nearly peeling the tyres off the rim in the process!
It’s a fun concept that could likely be replicated with off-the-shelf rocket motors, too. Throw us your ideas for better rocket powered transports in the comments below.
Many of us have had a radio controlled car at some time in our youth, though it’s probable that none all of us entirely mastered it. There are memories of spectacular crashes, and if we were really unlucky, further boosts to Mr. Tamiya’s bank balance as fresh parts had to be fitted.
[Paul Yan] was watching his young son with a radio controlled toy, and was struck by how the two-joystick control layout is not necessarily as intuitive as it could be. By contrast when faced with a console game with first-person view and a steering wheel the boy had no problem dropping straight into play. This observation led him to investigate bringing a console steering wheel to an RC car, and the result is a rather impressive FPV immersive driving experience.
His build took a PS2 steering wheel peripheral with pedals and mated it to an Arduino Uno via a PS2 shield. The Uno talks to a Nordic NRF24L01 RF module, which communicates with another NRF24L01 on the car. This in turn talks to a car-mounted Arduino Micro, which controls the car servos and speed controller.
FPV video is provided by a miniature camera and transmitter from the world of multirotor flying which is mounted on the car and transmits its pictures over 5GHz to a set of monitor goggles. Sadly he does not appear to have posted any of the software involved, though we doubt there is anything too challenging should you wish to try it for yourselves.
The video below shows the car in action, complete with an over-enthusiastic acceleration and crash from his young son. He tells us it’s a similar experience to playing a racing kart game in the real world, and having seen the video we wish we could have a go.
[TK] has a stretch goal for his RC car project — enabling it to recharge on solar power during the day and roam around under remote Internet control at night. It’s like a miniature, backyard version of NASA’s Curiosity rover.
Right now, he’s gotten a Raspberry Pi Zero and a camera on board, and has them controlling the robot over WiFi. He looks like he’s having a great time piloting it around his house. Check out the video down below for (crashy) remote-controlled operation.
We can’t wait to see if solar power is remotely possible (tee-hee!) as an option for this vehicle. The eventual plan to connect it via 3G cellular modem is still off in the future, and will probably demand more of the smarts of the Raspberry Pi than at present. But we love the idea of a long-running autonomous vehicle, so we’re pulling for you, [TK]!
Christmas has come and gone, and no doubt garbage cans are filling with toys that got but a single use before giving up the ghost. If you scrounge around, you might get lucky and score a busted RC car so you can be like [Mike] and build a completely unnecessary nitro-powered pencil sharpener.
This is one from the [Tim The Tool Man Taylor] “more power” files. To be fair, [Mike] acknowledges as much right up front, and as a learning tool for these super-powerful internal combustion engines, we think it’s a pretty cool project. After dealing with a seized cylinder on what looks to be a VX .18 engine rated at about 1.1 horsepower, [Mike] learns the basics of starting and controlling the engine. Once coupled to a pencil sharpener that clearly isn’t engineered to work at a bazillion RPM and jury-rigging a damper for the clutch, [Mike] fires up the engine and races through a pack of 10 pencils in record time.
The picture above looks like a standard four-wheel drive (4WD) touring car. As one looks closer, a few strange things start to pop out. Where’s the motor? 4 electronic speed controls? What’s going on here? [HammerFET] has created this independent drive R/C car (YouTube link) as a research platform for his control system. The car started off life as a standard Schumacher Mi5 1/10th scale Touring Car. [HammerFET] removed the entire drive system. The motor, differentials, belt drive, and ESC all made for quite a pile of discarded hardware.
He replaced the drive system with 4 Turnigy brushless outrunner motors, installed at the chassis center line. To fit everything together, he had to 3D print new drive cups from stainless steel. The Mi5’s CVD drive shafts had to be cut down, and new carbon fiber suspension towers had to be designed and cut.
The real magic lies in [HammerFET’s] custom control board. He’s using an STM32F4 ARM processor and an InvenSense MPU-6050 IMU which drone pilots have come to know and love. Hall effect sensors mounted above each motor keep track of the wheel speed, much like an ABS ring on a full-scale car.
[HammerFET’s] software is created with MATLAB and SimuLink. He uses SimuLink’s embedded coder plugin to export his model to C, which runs directly on his board. Expensive software packages for sure, but they do make testing control algorithms much simpler. [HammerFET’s] code is available on Github.
Since everything is controlled by software, changing the car’s drive system is as simple as tweaking a few values in the code. Front and rear power offset is easily changed. Going from a locked spool to an open differential is as simple as changing a value from 0 to 1. Pushing the differential value past 1 literally overdrives the differential. In a turn, the outer wheel will be driven faster than it would be on a mechanical differential, while the inner wheel is slowed down. Fans of drifting will love this setting!
[HammerFET] is still working on his software, he hopes to implement electronic torque vectoring. Interested? Check out the conversation over on his Reddit thread.
It’s built like a tank using 1″ square steel tubing and custom corner brackets made of 1/8″ thick steel. Heavy duty U-bolts hold the over-sized 5/8″ axles, and everything is driven using #35 roller chain. A large 12V sealed lead acid battery powers two CIMs (FIRST Robotics motor) with the AndyMark CIMple gearbox — these give the car tons of torque, and it can even do wheelies!
The really cool part of this project is the method of remote control. He’s using a regular old Xbox controller that an Arduino Uno listens to through a USB host shield and the original Xbox USB receiver. Simple, but totally effective.
The project is not yet complete, and he’s planning on fully equipping it with lights, a larger battery, a roll-cage, a camera system, and some kind of manipulator tool. Check out the test drive video after the break!