A Putter That Fixes Your Horrible Form

Golf is a game you can play for your entire life and still be pretty bad at. Getting a golf ball into a tiny hole by hitting it with a stick from hundreds of yards away is a pursuit that demands the precision of a surgeon and the temperament of a monk, yet usually results in the vocabulary of a sailor. Even when you find a rhythm, the game has a humbling way of reminding you that a misplaced pinky finger or a slight gust of wind can turn a perfect drive into a scavenger hunt in the woods.

Shane Wighton of the Stuff Made Here YouTube channel s tired of being terrible at golf, but doesn’t want to do the hard work of actually practicing to get better. So, as an engineer, he decided to throw technology at the problem instead. His solution is a robotic putter that automatically corrects your horrible shot, turning it into a hole-in-one every time.

Wighton thought that if the precise angle of the club face could be adjusted rapidly, it should be possible to build a system that could point it directly toward the hole before making contact with the ball. To test that idea out, he started by building a putter.

A custom putter head and shaft were machined, then a high-torque, low-speed brushless DC motor was installed at the top of the handle. It turns a driveshaft — which is hidden inside of the club’s shaft — that attaches to a worm gearbox that is attached to the putter head. This specific type of gearing prevents the head from moving out of place when it strikes the ball. To prevent the entire club from twisting when the motor adjusts the head, a slug of metal opposite the putter head was installed as a counterweight.

Now that the club was ready to go, Wighton needed to build a system to control it. To track everything of interest in three-dimensional space, reflective markers were attached to the club and ball. These are detected with sub-millimeter precision by a set of three OptiTrack tracking cameras. Using this information, Wighton developed an algorithm that precisely turns the putter head so that the ball always heads straight for the hole.

However, even with all this hardware, there are still a few caveats if you want to get a hole-in-one. For starters, you still have to hit the ball with the right amount of force. Furthermore, you have to swing the putter fairly slowly, otherwise the system can’t turn the putter head quickly enough to get it in the right position before contacting the ball. Aside from these concerns, there is also the fact that not all putts are straight shots. Uneven terrain, for instance, requires golfers to putt away from the hole and allow the ball to curve. Wighton's system can’t handle that yet.

This was a very complex build, and if the time spent had been invested in putting practice instead, Wighton would probably be able to sink a hole-in-one without technology by now. But there is no doubt that this solution is way more interesting!

If it is practice that you're after, you might be interested in Golf Ace.