Ben Kielstra, Vanoy Harris, Juan Benitez

As transportation infrastructure ages, there is a need to replace bridges that have been rendered deficient by age, increased traffic demand, overloading, or inadequate maintenance. To facilitate creativity in bridge replacement the American institute of Steel Construction (AISC) and the American Society of Civil Engineers (ASCE) co-sponsor an annual student steel bridge competition. Each team designs and builds a 1:10 scale model of a bridge. At the competition, the team must erect their bridge under simulated field conditions and bridges are judged on stability, stiffness, construction speed, efficiency, economy, and attractiveness.

Our bridge design included an aesthetically appealing arch to maximize the ratio of steel strength to weight. Our bridge performed well holding the total load of 2,400 lbs. while measured vertical and lateral displacement were below the design constraints of 3 in. and 1 in., respectively. We were placed second in the display category, which is judged by considering the aesthetic appeal of the bridge and the technical poster and fifth overall out of the eleven schools that attended the competition. The competition helped us become aware of real-world engineering issues such as cost, project management, aesthetics, safety, fabrication, serviceability, erection processes, and spatial constraints.

Automated Asphalt Shingle Removal System

Travis Vermeer, Dean Brummel, Zack Regnerus

Removing the old shingles is the most physically demanding aspect of shingling a roof because the old asphalt shingles, which are stuck to each other and to the roof, must be physically pried apart. Prying is usually done by thrusting a potato fork or special shingle tear-off tool under the shingles and then prying upwards. Current automated shingle removal tool designs automate the prying motion, but not the thrusting motion, which is the most labor intensive part of removing shingles.

Dan Venema, owner of Venema Construction in Orange City, IA, has been developing a prototype shingle removal tool that uses a cam guide to transform rotational motion into a thrust and pry motion to automate the whole tear-off motion. The goal of our senior design project was to refine his prototype by improving usability, reliability and manufacturability.

Our design features a refined cam guide profile milled from acetal delrin, which improves the life of the cam guide but is still easy to machine to the required shape, and a permanent magnet brushed DC motor with a linear torque curve that is mated to a planetary gearbox, allowing for good control and relatively low cost compared to the weight and power of the motor. We also modeled the complete tool in SolidWorks to further improve manufacturability, and we redesigned the tool so that it can be assembled using parts that are readily available from a supplier like McMaster-Carr.

Automated Skittles Sorter

Loken Vande Vegte, Jake Smith, Zach Van Engen

Interstates Companies (Sioux Center, IA) needs a way to demonstrate their automated control system technology at trade shows. We worked to meet this need by designing a machine that has the basic characteristics of an industrial feed mill sorting system: a hopper, an airlock, and a distributor. The final product will allow Interstates to better communicate their uses of control system technology.

Our group designed and built a sorting device that sorted Skittles candy. Skittles are placed in the hopper and each one passes through the airlock, where they are sorted by color, then the distributor arm places them into the appropriate bin. The plastic housing for the sorter, the hopper, the airlock, and the distributor arm were created using SolidWorks and a 3D printer. The control systems technology for the sorter uses an Arduino microprocessor to control the servo motors, proximity sensors, and an RGB light intensity color sensor. The sorter can be run directly by the Arduino or by a programmable logic controller (PLC) with a human machine interface (HMI).

Campground Design for the City of Emmetsburg, Iowa

Nathan Reichert, Caleb Van Weelden, Kendall Ackermann, Matt De Groot, Brian Meinsma

We collaborated with Bolton & Menk, a civil engineering design firm based in Spencer, IA, to design a campground for their client, the City of Emmetsburg (Iowa). The City of Emmetsburg desires to develop an existing 17-acre agriculture field into a full service campground in order to provide public recreational access to Five Island Lake and attract visitors to the area. The campground will also provide better accommodations for boaters, making the lake more accessible to them and promoting economic growth in the city of Emmetsburg.

As part of the project, we developed detailed construction documents for the horizontal layout, grading, and road cross sections along with the storm water, sanitary sewer, water supply, and electrical systems. Highlights of the campground layout include 46 RV sites, 11 tent sites, 4 cabins, a beach, a dock, an office, a playground, and trailer parking. In addition to the layout and basic civil and electrical systems that connect to the city’s existing infrastructure, we incorporated a site grading plan that required no new dirt to be brought to the site and a bioswale/raingarden system to manage storm-water runoff despite the incredibly flat site which made runoff design uniquely challenging. All of our design is in accordance with Statewide Urban Design and Specifications (SUDAS) and the National Electric Code (NEC). Bolton & Menk plans to use our design as a basis for the campground project which is scheduled to begin construction in the fall of 2016.

Electric Assisted Bicycle

Chris Slice, Bryan Hannenberg, Alec Korver

The goal for our senior design team was to design, simulate, and build an electric bicycle for use in northwest Iowa. In addition to creating an electric bicycle that will use a motor to assist the rider we had to consider speeds allowable by Iowa law and the typical distance between rural towns, since people often commute from one town to the next. An additional design criterion was that all the components be readily available so that our design can be duplicated.

Our final design is an electric bicycle that is optimized for a resident of northwestern Iowa. It is composed of high quality, off the shelf components to ensure that the final product is durable, low maintenance, and easy to repair. Key features of the final design are a mid-drive electric motor with an integral controller (Bafang BBS02) programmed to comply with Iowa law, an 8-speed internally geared hub (Shimano Nexus Inter-8) for easy pedaling and efficient use of the motor, a 52 volt, 20 A-h battery (Lunacycle 52v Samsung 26f 20ah) that allows a 30+ mile range for commuting between rural towns, and an ultra-light aluminum frame (Pure Fix Keiring 6061 61cm). We also wrote a detailed web-based simulation of the bike. The simulation allows users to draw a route in Google Maps and then the program estimates trip times and battery percentage used.

Watch a video of the e-bike in operation, or try the simulation.

High Volume Apple Cider Press

Brendan Conley, Jeff Carlson

Apple cider pressing builds community among friends and neighbors as people gather to press apples. However, pressing apples to make cider can be time consuming and difficult to use because of the manual effort required to press the apples. Our customer, Prof. Duane Bajema, envisioned a cider press that was simple to use, easy to clean, and portable, but that also eased the physical burden of cider pressing, enabling more people to use it. This would also mean that more people would feel that they can press their apples into cider, so fewer apples would go to waste.

Our cider press design eases the manual labor by using a hydraulic system to press the apples. A hydraulic cylinder, which can exert 8300lbs, moves a press plate to squeeze the juice from the apples. All the parts that touch the cider are made of food grade aluminum or stainless steel and are removable for easy cleaning. The grinder is connected to a motor, which reduces the amount of effort required to pulp the apples. Finally, our design fits on a trailer bed so that it can simply be hooked up to a vehicle and easily moved anyone’s apple trees.

Human Powered Vehicle Design

Tim Brouwer, Phillip Landon-Ruther, Gerrit De Raadt

Human powered vehicles have been around throughout human history and today in North America a particular type of human powered vehicle, the bicycle, enjoys widespread recreational use. However, it can be difficult to carry groceries home or products to market or to ride anywhere in northwest Iowa in January on a typical bike. These factors limit the widespread use of a bike as a form of transportation in many cultural contexts, including our own. To encourage innovations in human powered vehicles, the American Society of Mechanical Engineers (ASME) hosts an annual competition for university students. The goal of our senior design project was to create a vehicle that meets the ASME competition design standards.

Our group’s vehicle featured a lightweight frame design made of 1/8 inch aluminum tubing TIG welded together and inexpensive, repurposed drivetrain components from two used bicycles. Computer models and physical tests of the frame verified that the rollover protection system meets the ASME competition standards for protecting the driver from side or vertical impacts.

One Body, One Hope, One Bridge

Kyle Vander Zee, Austin Lindemulder, Peter Hoelsema, Eric Fedders

One Body One Hope, a mission organization based in Sioux Center, partners with Abide in the Vine Disciple’s Church to operate a farm in Liberia, Africa. A small creek separates most of the farm’s land from the market. In order to effectively grow and harvest that land, they needed a bridge to transport large equipment across the creek. With this bridge, they will be able to expand the farm from 16 to 110 acres (and possibly more in the future).

During the fall semester, our team designed the bridge, and over Christmas break, we traveled to Liberia and constructed the bridge. In many ways, the design mimics the small service bridges on farms throughout North America. The wooden bridge deck is supported by two refurbished steel I-beams from the recently demolished Sioux Center Hospital. The I-beams rest on cast-in-place concrete footing-pedestal foundations on either side of the creek. The road’s approaches were built using compacted soil taken from the site location, and rip-rap was used to protect against erosion. The bridge spans 53 feet, is 12 feet wide, and has a total weight capacity of 30 tons. It will serve the nearby farm and local villages.

Toys for God’s Kids

Josh Meinders, Monte De Kam, Nick Arkema

Toys for God’s Kids (TFGK) manufacturers wooden toy cars for children around the globe. The local chapter of this Christian charity was interested in reducing tedium and improving the ergonomics associated with the car manufacturing process, particularly during wheels cutting and logo branding. They were also interested in improving the sound quality in their shop while the router was running (most of the time) so that volunteers can talk while they work.

We improved wheel production by repurposing one of TFGK’s existing computer controlled mills, which automated wheel cutting and freed a worker from having to manually cut a large number of wheels using a drill press. We designed and fabricated an automated branding machine to brand two logos onto each car, replacing a repetitive and physically uncomfortable by-hand process. Finally, we halved the noise coming from the routers by adding both a variable speed control and a sound-absorbing housing around the router blade, which enabled the workers to communicate and enjoy camaraderie while they work.

Volleyball Impact Force Sensor

Ben DeVries, Tayler Hoekstra

As volleyball becomes a popular sport for girls in middle school and high school more players are experiencing shoulder injury before reaching college-level sports. Some of the causes of these injuries, particularly those related to forces from repeated overhead movements like hitting and serving, are unknown. Our goal was to design a wearable force sensor for the hand to help better understand the forces on the arm caused by hitting or serving a volleyball. The device needs to measure the magnitude and location of the force between the hand and the volleyball while being small and light weight so that it does not affect the player’s hitting motion.

Our team created a device capable of recording both the magnitude and location of forces induced on the hand of a volleyball player from a volleyball hit. The device is composed of an array of 13 Flexiforce resistance-variable sensors attached to a baseball-batting glove. The force sensors are wired to a data acquisition (National Instruments) device that feeds the force sensor voltage to LabView program which converts the voltages to forces and displays the maximum magnitude at each force sensor. Data from all sensors is recorded so that the center of pressure (the location of the force) can be determined.