At this point, Shane Wighton of the YouTube channel Stuff Made Here has gone from being another talented maker sharing their creations on the internet to potentially the next Thomas Edison. Their latest invention, an auto-aiming bow is so accurate it can even shoot a tiny apple off the head of a Lego minifigure.
Previously, Wighton has used their design and engineering expertise to create a custom-shaped backboard that ensures every basketball shot is redirected through the hoop, an updated version that uses object-tracking cameras and motors to reposition the backboard with every shot, and even a baseball bat with a built-in explosive core that could literally blast home runs out of a park. Through science and engineering, Wighton is slowly mastering every sport imaginable, and that now includes archery with a wonderfully over-engineered bow.
Shooting an arrow at a target usually requires relatively simple hardware. Essentially a bent piece of flexible lumber with a string connected to each end. When you pull the string back and release it, the flexed bow returns to its original shape, and energy is transferred to an arrow, sending it flying towards a target. The idea is simple, but mastering the use of a bow so that the arrow actually hits the target can require years of practice… or several weeks of engineering.
The first iteration of the auto-aiming bow consisted of two mechanisms: a hand-held robot that positioned the bow up and down and left or right using a pair of linear axis motors to take care of aiming, and a second robot that would hold and release the drawn string, to take care of the timing. A series of OptiTrack motion capture cameras installed around Wighton’s shop link up with trackable sensors attached to the bow and the target and some custom software to translates what the cameras see to the auto-aiming mechanisms.
The initial results were disappointing with the auto-aiming bow unable to actually accurately hit a target. Wighton eventually realised the type of bow he was using required the arrow to be fired around the bow itself, which introduced slight wobbles in its flight that threw it off target. Archers learn to compensate for these arrow flight deviations over time, but Wighton just threw money at the problem and upgraded to a compound bow with a whisker biscuit that guaranteed the arrow flew straight and true with every shot.
The compound bow introduced another problem: the entire rig became too heavy to hold, and the solution to that problem was — you guessed it — more hardware. Hollywood relies on a wearable device called a Steadicam that attaches a heavy film camera to an articulated spring-loaded arm that’s worn by a camera operator allowing them to capture smooth footage even while running. Instead of a heavy camera, Wighton strapped on a Steadicam rig and attached their auto-aiming bow, which from that point on worked almost flawlessly, even tracking and knocking moving targets out of the air.
The auto-aiming bow wasn’t perfect, however. As Wighton points out at the end of the video its ability to compensate for targets farther away — which requires an archer to aim higher to account for the arched trajectory of an arrow — was completely lacking. The contraption isn’t ready for the Olympics just yet, but version two is already in the process of being designed and improved. At some point, we might see Wighton actually splitting arrows just like Robin Hood did in the movies.