By: Gabriella Cipriano, Student Written Communication Specialist, UConn School of Engineering
Most of the equipment sold by commercial farm-supply companies are too big and expensive for small farms, leaving them in the lurch when it comes to employing time-saving technology. But, a farmer’s biggest commodity is time, so it is up to these smaller farmers to create their own equipment suitable for their individual needs that can increase efficiency.
Three University of Connecticut mechanical engineering majors — Kylie Kearney, Justin Gallo, and Andrew Alaba — are working to build a small and efficient bean thresher that will increase the productivity and sellable product for local small farmer, Susan Mitchell, and her farm, Cloverleigh Farm.
At a size of only 2 acres, Cloverleigh Farm is located right here in Mansfield, catering to residents, local restaurants, and even UConn dining services. The farm uses “sustainable production methods that are good for the earth… [and is] certified organic by Baystate Organic Certifiers,” according to the website. “We are the only certified organic farm in the town of Mansfield.”
A bean thresher, a mainstay for farmers with bean crops, are extremely helpful when it comes to harvesting. According to Kearney, the device “breaks the [bean] pods off the plant, and then the beans out of the pod so that the farmer doesn’t have to manually break open the pods to get the product.”
Currently, Mitchell separates her beans by putting them in a bag and whacking them against the ground. Not only is this method extremely labor-intensive, but it also takes too much of her time that can be used towards harvesting carrots. According to Kearney, “If she were to buy a commercial bean thresher, it would cost “around $100,000 to $300,000… which would be her revenue for multiple seasons.”
Since there is not a lot of research done on dried beans, starting this project required the team to work backwards. They spent about a month conducting physical experimental tests as well as simulations. Gallo explained that they did “experimental drop tests as well as a pendulum test to find the impact breaking strength required to break open both the beans and the pods.”
Though they didn’t know each other prior to being paired for this project, they soon realized that they each specialized in different skills. Gallo knew a lot about the simulation software ANSYS, and used it to validate their experimental results and visualize the model of their bean. Alaba has a lot of SolidWorks knowledge, and also a lot of experience using equipment in the Machine Shop, so over winter break, he cut the wood for the thresher’s main structure.
As the design for this bean thresher has developed, the team came up with the idea of “a less dynamic conveyor belt, having a low friction plastic that [the beans] could slide down, with a ramp,” according to Kearney. Gallo explained how they chose an “ultra-high molecular weight polyethylene plastic… because it has a very high abrasion resistance, so it’s going to be really durable.”
They are now looking for a motor with an adjustable speed dial, and plan to connect it to a dimmer switch (similar to a switch used to dim/brighten lights in a room) to adjust the voltage. Considering Mitchell wanted something stationary, the thresher can be kept in her old dairy barn and the motor will run on electricity.
Looking at the actual journey the group has been on, with such a large and complex project, each member expressed some twists and turns as they’ve gone through the year. One obstacle mentioned was the experience of having a lot of back-and-forth on ideas, and the uncomfortability in the beginning of not asserting themselves. To help with this, the team utilized pew charts to determine the best ideas, ranking each based on positives and negatives, and choosing the highest-ranked options. This process allowed them to get comfortable with each other, and feel more confident in making the best decisions for the project.
The team is proud to say that they are ahead of schedule, despite encountering some issues throughout the year. After reconstructing the initial design four times and receiving warped and splintered plywood, they are finally seeing successes. A huge accomplishment of theirs was impressing their sponsor, and gaining her support.
“She’s so proud of us,” Kearney said. “It’s become a lot more to us because now we want to succeed for our sponsor.”
This article is part of a multi-part series on engineering students and their journey through senior design. Part two of this team’s journey will come out in April 2020.