The “Grain Weevil” is a life-saving piece of machinery designed to keep farmers out of grain bins. The company’s mission statement, “No Boots in the Grain,” is made possible with the Grain Weevil robot that does the dirty, dangerous work of managing stored grain.
Grain Weevil has been creating buzz in the ag community since father-son team Chad and Ben Johnson introduced their first prototype back in 2021. Ben was studying electrical engineering at University of Nebraska when they received the special request from friend Zach Hunnicut. “Hey, look, you guys build robots. Why don’t you build me a robot so I and my children never have to go into a grain bin again?”
Hunnicutt knew all too well the dangers of being inside a grain bin – his great uncle died in a grain bin accident when he was young. Unfortunately, stories like his are not uncommon. According to the 2023 Summary of U.S. Agricultural Confined Space-related Injuries and Fatalities, there were 29 fatal cases and 26 non-fatal cases involving agricultural confined spaces in the United States. This represents a +33.7% decrease from the 83 cases documented in 2022.
Unfortunately, entering a grain bin is often unavoidable as there’s not much else to be done when the grain clumps or clogs. But even after being stationary for long periods of time, grain can settle beneath someone who is inside the bin, which can quickly lead to entrapment.
Entrapment, also known as grain engulfment, is just what it sounds like – a person gets overtaken by grain. There are three ways this can happen: entrapment in flowing grain, collapse of a grain bridge, and collapse of a vertical wall of grain. Entrapment can occur in four to five seconds, and full engulfment can result in only 22 seconds.
The risk becomes extreme when machinery such as an auger is running, making it more likely that someone in the bin will be pulled down into the moving grain as it is flowing. Once entrapped, it is nearly impossible for a person to free themself. One foot of grain in a bin can create about 300 pounds of pressure, which also makes it extremely difficult for others to pull someone out.
Falling from the grain bin or losing a limb to one of the augers are other common accidents. Chad Johnson also notes another risk of grain bins. “One of the things that surprised me most was that at any given time, 8-10% of farmers in the United States have farmer’s lung, which is a lung disease caused by breathing grain dust.”
The Johnson’s designed the Grain Weevil to perform all the chores that need to be done in a bin full of grain. The autonomous robot cruises through grain with a pair of mini augers that perform all the tasks a human would do, including leveling and breaking up grain crusts, doing inspections, and feeding grain into the extraction augers.
As Ben recalls, “It started in the shed just putting it together with whatever we had. Now you can see we’ve really grown the team and been able to engineer this thing to be powerful and capable inside the bin.” A single “Version 1” Grain Weevil can manage up to 500,000 bushels of grain. The robot has a camera system and is designed to be operated remotely by a human.
While Version 1, dubbed “the workhorse,” does have some autonomous capabilities, it can’t operate on its own. However, the company says a forthcoming model will have that capability.
Starting this fall, Grain Weevil began providing the robots as a service to farmers in the Midwest through the “BinAssist Network.” The company is targeting the second quarter of 2025 for the first commercial release of its robots. For now, Grain Weevil will focus on Midwest states before expanding to other regions and crops. The map below shows local providers in Illinois, Indiana, Iowa, and Nebraska. The company is also currently running trials at commercial grain facilities, which have “very similar challenges, just more demanding challenges.”
We’ve followed Grain Weevil’s progress over the years and are super excited that they will be attending FarmCon in January. Check out a video of the Grain Weevil in action HERE, and learn more at the website HERE.
