By Mark Jones
The knife drawer in the borrowed vacation house didn’t contain knives. It contained knife-shaped hunks of dull steel. The only explanation for the overflowing drawer was that the owner didn’t understand that knives could be sharpened. I didn’t have my knife-sharpening paraphernalia with me — I was, after all, on vacation. Fortunately, a previous trip to the hardware store introduced me to something I hadn’t seen before. The hardware store had a robotic knife sharpener.
I carry a pocketknife. I have for decades. I feel lost without it. My knife is always sharp, very sharp. I’ve long prided myself on being able to put on a keen edge the old-fashioned way, by hand. Diamond sharpeners have replaced the whetstones and oil of my youth. I’ve also, when I’ve really mangled an edge, resorted to the knife sharpener — a person — at the farmer’s market. It is common to see knife sharpeners at the markets we attend sitting behind a 1-in. belt sander generating sparks. I didn’t realize their days were numbered. I hadn’t realized knife sharpening had gone robotic until I encountered Resharp at a hardware store in Cedarville, Mass.
If you’ve bought hardware, you’re likely familiar with Hillman. Bagged nuts and bolts frequently bear the Hillman name. Same with the nuts, bolts, and other assorted hardware that comes out of pullout drawers. I found Hillman to be more than just nuts and bolts. It’s robotics, too.
The Resharp was acquired by Hillman. It is a patented system for robotically sharpening knives. It consists of a vise, a vacuum system, and a moving head that contains optical inspection and two grinding stations. All are under the control of a computer reported to be a Raspberry Pi. The vise holds the knife and moves it up and down. The head moves back and forth while grinding and inspecting the knife. The vacuum system keeps it clean.
I took four knives to be sharpened, ranging from 4 to almost 12-in. Three were curved blades, one straight. Kayla left the checkout to sharpen the knives. She is clearly a generalist, not a knife technician. She cheerfully locked each in series into the vice, used a laser to set the location of the heel of the knife, and pressed start. The head started moving in the deliberate way that robotic systems do and scanned the blade with the red laser. A spin of the head and the first grinding pass commenced. It was followed by several more before the head moved to home position and signaled Kayla that it was done. One by one, sharp edges were produced, very sharp edges. Each knife took minutes, far less time than it would take me or at the farmer’s market.
Looking into the patents made it clear this is not the first robotic sharpening system. It does appear to be the first specifically designed with a focus on consumers rather than professional knife-wielders. I found several companies selling industrial systems designed for the meat-packing industry. All purveyors of robotic knife sharpening tout the speed and reproducibility. Surprisingly, safety is also mentioned. Every company, including Resharp, that sells knife sharpening tooling, whether robotic or manual, claims a sharp knife is safer than a dull knife.
I’m not sure what to think of the robots coming to knife sharpening. Most people can’t hand-sharpen a knife. Robots in hardware stores bring sharp knives to the masses. Assuming sharp is safer, that’s a good thing. Sharpening rather than replacing is also a good thing. I’m no Luddite, but I do find satisfaction, maybe even pride, in my ability to put a good edge on a knife. There is something primal about it. Perhaps it is because sharp edges have been important to humans for more than two million years. I don’t have the same affinity for key making or engraving, the other areas where robotics has crept into the hardware store. I have no sense of loss when duplicating a key at a kiosk. Standing in front of the Resharp, my sense of amazement was replaced by a sense of loss.
Filed Under: Commentaries • insights • Technical thinking
