Auto-Aiming Putter for Mini Golf Corrects Your Swing in Real Time

Shane Wighton, the engineer behind “StuffMadeHere,” has just revealed his new invention, a mini golf putter that automatically adjusts its face angle on the fly to get the ball into a hole with ease.

Wighton worked on this project for almost 300 hours in total, primarily to level the playing field with his wife, who excels at mini golf and frequently outperforms him. He wanted a putter that’d give him a break from those frustrating times when he just can’t quite put the ball in the hole despite his best efforts. From the surface, it appears to be a standard-looking club with a machined head and a lengthy shaft, but within it houses a beast of a high-torque brushless motor coupled via a driving shaft to a worm gearbox that allows it to rotate the head around a vertical axis. This configuration maintains the head steady at impact while allowing for extremely quick modifications mid-swing.

When you press the button on the handle, the entire system kicks in. High-precision Optitrack cameras track reflective markers on the shaft, head, and even the ball itself; software then utilizes that motion data to forecast the swing path and speed, and commands the motor to guide the head straight toward the hole.

All of this occurs inside a 200-millisecond timeframe, which is faster than you think. The putter recognizes the start of your backswing, plots the club in 3D space to calculate the necessary correction, and then rotates the head to face the hole before the ball strikes it. Any wobble or hand shaking is corrected in real time, with the system syncing the tracking data with the motor orders to compensate for any delays.

In early iterations, the main issue was response forces from rapid motor movement, which caused the shaft to twist and throw off accuracy. Wighton considered using an inertial counterweight to cancel out the torque, but eventually switched to heavy inertia rings on the motor to achieve balance. He also used a temporary rubber band to eliminate gear backlash during testing and machined the club head on a five-axis mill to achieve the desired tolerances. Other elements were created by 3D printing and water-jet cutting.

To properly test the concept, Wighton created a variety of custom mini golf holes out of modular parts like as wood frames, steel tubing, and artificial turf. He devised a variety of difficult scenarios, including straight pathways, banks, and obstructions, to test the system’s capabilities.

Let’s just say there were a lot of issues along the road, such motor cogging, magnetic interference from nearby tools, and software faults that caused the thing to go wild. But after over a thousand test swings, it all began to come together, especially when he enhanced the control loop by comparing past tracking data to current motor positions to eliminate latency difficulties. The results are quite spectacular, with the putter directing balls into the hole from all angles and distances. It can manage bank shots by calculating the rebound route, work one-handed or blindfolded, track a moving hole on a motorized platform, and perform all of this in full darkness.