This Full

Nov 14, 2023

Sitting on the couch is a pastime that many people enjoy, but being there for hours on-end can get quite boring as it sits still in the living room. Will Dale in his driving couch project has transformed this stationary piece of furniture into a somewhat fast and even dangerous vehicle that can travel across a variety of surfaces with only a PS4 controller in-hand.

After ordering a multitude of parts, Dale gutted the internal springs, cushioning, and any wooden bits that stick out, such as the legs at each corner. From here, a 3D model was designed in order to plan where everything would go and how exactly it would fit together. The frame was fashioned by cutting 1-inch steel tubing into sections and welding them together, with a solid rectangle on the outside and several inner pieces for extra rigidity.

With the frame now constructed, Dale turned his attention to the steering assembly. One big challenge was that he needed a fast, accurate way to turn the wheels without the need for a complicated mess of gears, motors, and sensors. Two arms were attached on both sides of a front crossbar, with the wheels spinning freely around their axles. Bolts were added to the arms, and each one was welded to a central pivot point that could be pushed or pulled by a single linear actuator.

Because the couch would need to haul up to 800 pounds without a preemptive push, getting the correct amount of torque was paramount. The main drive axle had a large sprocket, brake disc, and bearings fitted so that it could both start and stop with external controls. A secondary jack shaft axle sits just in front of the main axle, and its purpose is to convert the high-speed, low-torque motion of the motor into low-speed, high-torque. Finally, a single set of brake calipers were added around the disc and had a wire attached so that the driver could brake by pulling it.

The couch uses a pair of 72V 3000W brushless DC motors that each have their own electronic speed controller (ESC), which takes in low-voltage signals from an external source and converts them into high-power outputs. Powering everything is a custom battery bank formed from 320 18650 lithium-ion battery cells that had been spot-welded together using nickel strips. In all, it could output 72V at an impressive 40Ah.

To go from a flick of the thumb on the joystick to moving the couch, an ESP32 was configured as a Bluetooth server to read the incoming packets from the controller and convert them into actions. Some of the buttons were mapped to toggling the underglow, activating the horn, or other functions, while the left joystick steers and the right trigger drives the motors forward.

To see what Dale does with his newly-minted electrified couch go-kart, you can watch his video here on YouTube.