Grain Indicator

Ally Schulte and Kyle Othersen

Problem Statement

Farmers regularly climb ladders and metal staircases to the top of their grain bins to measure the height of the grain, which can pose risks and be unsafe, especially for older farmers. Current solutions, such as LevAlert and Grain Gauge, are expensive and unreliable, therefore frequently unused. The process for measuring grain must be cheap, easily installed and accessed, precise, and safe.

Problem Justification

There are 2.2 million farms across America. Managing grain height can pose hazards to farmers of all ages, but is specifically dangerous to the elderly and those lacking an able body. This is prominent in the farming community because 50% of farmers are 55 years of age or older. Looking in the top of the bin has it’s own risks. Entering the grain bin, on purpose or accident, can bring about injury for the farmer. Methane gas is produced in the bin, which over time will outgas and displace the oxygen in the top of the bin. Entering without any other precautions can knock a person unconscious, and silently suffocate them to death. Anyone unable to purchase or install a device currently on the market has to climb a ladder to determine the amount of grain, putting them in harm’s way.

Grain Bin Background

The smallest grain bins have a 15 ft diameter and can hold 1600 bu. The largest grain bins have a 135 ft diameter and can hold 1.2 million bu. According to small farmers Ryan Clark, Chris Frizzell, and Cory Schulte, grain amount is roughly estimated on small farms. Most farmers tap on the bin to tell the difference between full and hollow at certain heights. Larger, richer small farms purchase visual readers to show the height of the bin. Farmers must measure the height of the grain in order to understand how many more truckloads they can load or unload before it overflows or is empty. On a farm, grain goes from the field, through tractors and augers, to be emptied into the grain bin. From the grain bin it is emptied through the bottom into an auger, then poured into a grain truck and sold to a grain elevator.

Design Goals

The goal of the new solution is to improve accessibility, safety, price, precision, ease of installation, and maintenance. The grain height should be easily accessible. Farmers should be able to determine the amount of grain in a bin with minimal effort. The farmers should be safe using the new product. There should be little to no risk when testing the grain height. The price of the device needs to be low, making it readily available for small farmers who don’t have much money to spend on something they can do for free with only a little more risk. The height should be discovered precisely. There should be an extremely small margin of error in the measurement. The height must be established to the nearest foot. Farmers or an installation crew should be able to safely and easily install the new product. The maintenance on the device should be low. A farmer should be able to use it for decades without replacement.

STEM Application


We performed a properties analysis on existing grain measurement systems. We made a matrix to judge the accessibility, safety, ease of installation, precision, and expense. This is a scientific process of evaluating the other devices. We also used the sciences in our multi-platform solutions: Laser, Sonar, Gravity, Simple Machines. The use of this broad array of concepts is scientific because we are opening ourselves to all the types of technology available and testing each.


A pulley system and power drill cranking system are utilized in this process. A pulley is a simple machine and a power drill is more advanced technology. The device uses an array of technology to perform it's task. The project has minimal advanced technology because we initially interviewed and analyzed farmers and the amount of technology usage they would appreciate in the device. Farmers are generally older and less likely to want to learn about new technology, so we kept the device simple.


Our group performed risk management by judging safety and environmental concerns. Fitting our engineering knowledge of surrounding and weather to our project was an engineering process. We also made material changes based on their properties and the weather conditions.


Concepts of mathematics were used in the project to prove the tape measure markings with match to the markings on the bin. The cost analysis for the design also required mathematics to discover the product cost due to materials used.

Market Analysis

There is little market for the current solutions in existence. This is because farmers have very little money to spend on a device that isn’t required for their farm, let alone hundreds of dollars to give to something that they will need to replace in three years. Farmers I have spoken to, including Ryan Clark, Cory Schulte, Michael Hamilton, and Chris Frizzell, have stated that a cheaper version of a grain height measuring device would be useful and widely used. A new device would be marketed to small farmers with the idea of time efficiency and less effort. It could also be marketed to larger companies and grain elevators with the promise of higher safety. This device will always be useful, as farmers will always need to measure grain amount for management, bookwork, and selling purposes. In order to properly advertise and reach the most amount of farmers possible with the new product, rights to manufacture would need to be sold to John Deere or another large farming company. Companies such as John Deere are well known and have the money to market a new product. Research has shown that companies started on the idea of measuring grain height, such as Grain Gauge and LevAlert are less known and therefore much less profitable.

Codes and Regulations

Grain is sold based on qualities such as weight, foreign matter percentage, and moisture level. The new design does not alter anything about the grain, so it will not break any pre existing codes or regulations.

Benefits v. Risks

A new product should be developed to fill the demands of the farmers. The benefits of the new product outweigh the risks. As most manufacturing goes, pollution will be created in the machines that shape the parts and any vehicle transporting the materials will consume oil and also pollute the air. The development of the project will give more jobs to people who produce, transport, and sell the product. It will improve the net worth of John Deere or whichever company sells the device. The product will improve the production rate, as farmers won’t have to climb the bin after each truckload. Society will be better off with this product as they will not have to worry about their loved ones falling or getting injured on and around the grain bins. If the product doesn’t work or breaks, the worst thing that could happen is the pulley derails from the track and the farmer must climb the bin like normal and place it back on the track. The failure will cause no more risk to safety than a farmer would have normally climbing the bin. Features have been put in place for the device to reduce risk of the rope breaking or the weight getting stuck in the corn. The rope has a track to follow on the edge of the bin roof, keeping it safe from sharp metal and possible fraying. The weight on the inside of the bin has a flat bottom and is fairly light to reduce chance of it falling beneath the surface of the grain. Little to no risks are posed if it were to sink, but the farmer would have to exert more effort on the rope to remove it.


Loads will be static on the device. The only load will be the 7lb weight on the end of the rope. This load will be exerted constantly on the rope, pulley, and vent. The pulley and vent are made of aluminum, so they can withstand a constant 7lb force.

Mechanical Engineering

The design requires no heat or mechanical power. There are moving parts in a simple pulley. The rope slides through the aluminum pieces easily and the load will be directly transferred from the rope to the pulley wheel to the tape measure. All parts move at an ideal speed as to not injure the user.


The product requires energy from the farmer. Farmers must pull the rope with the 7lb weight. The farmer’s force is exerted on the rope, which is then exerted on the pulley wheel and 7lb weight.

Product Lifecycle

The assembly and packaging for the product would run completely through the John Deere company. John Deere uses reusable containers to ship all products between manufacturer and stores. The company would decide the packaging for the device, possibly using biodegratable plastic, cardboard, or a standardized tote.

Project Collaborators

Ally Schulte is a senior at Timberland High School involved in this project through the PLTW Engineering Design and Development class. She is going to Missouri University of Science and Technology to double major in Civil and Architectural Engineering. She was originally interested in this design project because she has family that are small farmers and this has always been a problem on their farm.

Kyle Othersen is a senior at Timberland High School involved in this project through the PLTW Engineering Design and Development class. He is going to Johnson Community College to become a Locomotive Conductor/Engineer for Union Pacific or Norfolk Southern.

Project Mentors

Cory Schulte is a farmer at Clark Farms in Brookfield, Missouri. He originally suggested the problem that farmers climb and tap on bins to determine the height of the grain. He is connected to this project because he is Ally Schulte’s father.

Emily is a mentor from Pennsylvania. She was assigned to the Engineering Design and Development class through Mentored Pathways. She studied Chemical Engineering at Rowan University and has assisted constantly via email throughout the project.

Ryan Clark is a farmer at Clark Farms in Brookfield, Missouri. He brought information about LevAlert, Grain Gauge, and the mechanical floor to the project. He is connected to this project because he is Ally Schulte’s uncle.

Michael Hamilton is a Grain Superintendent at Ray Carroll in Slater, Missouri. He explained and toured a grain elevator and introduced the SmartBob and it’s commercial uses.

Chris Frizzell is a small farmer in Brookfield, Missouri. He gave the project insight to the thoughts and habits of other small farmers. He is not technologically inclined, which demonstrates the older population of farmers.

Previous solutions

LevAlert / Grain Gauge Smart Bob Tape Dropper

Solutions that farmers have for checking the grain height without climbing the ladder are to install a staircase on the bin, use LevAlert or Grain Gauge, use a SmartBob Tape Dropper, or install a Mechanical Floor. New grain bins have staircases instead of ladders, but the metal staircases are still extremely dangerous and the farmer must still spend time climbing the bin and tapping on it. LevAlert and Grain Gauge are practically the same device, manufactured by different companies. They are simple devices installed at various levels. Each device costs roughly $100 and two or three devices per bin still may not be precise enough for a farmer’s needs. The SmartBob Tape Dropper is a device that is used at the Slater elevator. It is installed in the roof of the bin and automatically drops a bob down into the grain and report the distance of empty bin back to a farmer’s computer. The mechanical floor is a device some farmers install when they first build a bin. This is a device that weighs the grain in a bin and reports it back to a computer. Through a decision matrix, we decided the most practical device is the SmartBob Tape Dropper. It is ranked better than the other methods due to its safety and accessibility. The worst methods are LevAlert and Grain Gauge due to their high maintenance and difficulty of installation.

Grain elevator tours: Mendon and slater

Grain elevators are the facilities that farmers sell their grain to at the end of the season. Elevators store and manage much larger amounts of grain than regular farmers.

Trucks are brought in to the grain elevator and weighed to check the amount of grain. Then a sample of grain is taken to measure the amount of moisture and foreign material levels. All measurements are recorded on paper slips, then later recorded into the computer to determine price.

Many of the stairs, ladders, and elevators, like those on normal grain bins, are hazardous for farmers. A lot of climbing is necessary, even at large elevators, just to measure the height of the grain in the bins.

There are a lot of mechanics involved in collecting the grain and managing the places grain is located in the elevator. The grain brought by the farmer is dropped into a pit, to be pumped out into a bin. The middle picture shows the Grain Superintendent's computer, monitoring the grain levels in each bin. All but two bins in the diagram are amount measured and inputted by hand. The closet shown on the right is one of many of the electronic panels managed by the elevator to keep the grain moving between the bins mechanically.

New solution ideas

Solution ideas included using sonar and laser technology to penetrate the sides of the bin to measure the level of the grain. If this was not feasible the sonar/laser could be mounted at the top of the bin and shot down the height inside. the problems with this technology was that for a sonar to be able to penetrate the sides of the bin or reach the bottom of the largest bin from the top, it would cost over $1000 for one unit. The problems with the laser tech is that there would be too much dust in the bin and it would obstruct the laser and give false readings, they also cost upwards of $500 per unit.

The solution we decided upon was a simply pulley system, as it kept cost down and functioned the smoothest.

prototype Video demonstration


Video 1:

1. Pan of the grain indicator prototype

2. The carabiner is unclipped to allow the pulley to move

3. As the line is unreeled, the weights inside the bin lower towards the grain

Video 2:

1. The line is unreeled to the point where the weights rest on the grain

2. Each tick on the rope represents a foot, so they are counted

3. Each tick on the bin also represents a foot, so they are counted from the top

Things to note:

1. The videos have no sound

2. The foot measurement on the rope is different than the foot measurement on the bin (a mistake on the prototype which will be adjusted in the actual device)

Copy of Video.MOV

Video 1

-1 In the first video we showed the new design of the weight, we designed a cone shape so that the weight could be pulled out easily if it were to be submerged in the grain.

Video 2

-1 In the second video we showed the new design of the crank and the tape on the side of the bin. The tape allows easy counting without having to spray Numbers on the side of the bin.

-2 The crank we designed to either be hand cranked or by using a power drill.

Copy of Video_1.MOV

Lab Procedure

-Roll up pulley to fully simulate use

-Adjust grain height

-Record actuality height

-use device

-record device grain height

-repeat steps with different heights

Problems with the lab

-We could only measure heights of grain that the bucket used to store the grain allowed.


The device worked quickly and effectively

Main problems with the incorrect readings are the grain height was a place halfway in the foot measurement.

Depending on how you count the feet, you can be off by up to a foot.

The weight sunk farther into the corn than soy beans, but not far enough to skew the readings.

Safety Edit -

The crank, for the safety and convenience of the farmer, has a manual option, and an option to reel or unreel using a screwdriver/drill as a motor.

The reel is secure in the stand, so the tension lies on the stand, not on the rope.

This makes it impossible for the reel to accidentally unreel quickly, reducing risk of hitting the farmer with the handle.

User Edit -

The weight, to prevent possible user errors, has a pointed top to allow for easy removal from grain.

If a farmer forgets to remove the weight before filling the bin, this design of the weight will help prevent breaking the device.

The bottom is large and flat so the use of the weight to sit on top of the grain will not be altered.

Weather Edit -

This piece is to be bolted over the pulley on the edge of the grain bin. Its function is to prevent the rope from ever derailing from the pulley wheel.

In high winds, the rope is liable to flap and move, but with a cover over the pulley, the rope cannot possibly fall off.

This allows the device to be safer, but also increases the longevity of the device, so the farmer will not have to climb the bin and fix parts after a major storm.

Ameren display: Poster and prototype


We were given the idea to redesign to incorporate the mistakes farmers may experience while using the device.

We redesigned the weight to be cone shaped, so it could be removed from the grain if an accident occurred or the farmer forgot to roll up the weight.

We also expanded the lifespan of the device and weatherproofed the rope.

The cost analysis was updated on the poster to correctly display the max and minimum prices.

Schneider electric display: Poster and prototype


We were given numerous positive reviews from engineers. Much of the criticism came from people suggesting we paint numbers on the side of the bin instead of tick marks. This would improve the process by making the device be used faster. We, however, did not use this suggestion because to paint numbers instead of lines, stencils would be required and the painting time would increase drastically. The price and ease of installation would increase to have numbers.

Design Process Reflection

1. Define the Problem

Many problems were presented to us and among ideas with Parking systems, Microwaving timers, and phone holders, we decided the grain indicator problem posed the biggest safety hazard and time inefficiency. After selecting the problem, it was researched in depth. We visited two grain elevators and did vast research on age of farmers and resulting deaths due to grain ladders.

2. Brainstorm

Many ideas were brainstormed, such as electronics, pulleys, holes in the bin, and a new bin material. In brainstorming nothing was immediately turned down, but in the following days we had to limit some of the solutions to the most valid.

3. Recognize and Generate Ideas

As seen above in the current ideas area, some of our design ideas were Laser measuring, Sonar, Stud Finder technology, or pulley system. These ideas were the most viable and posed no upfront problems.

4. Identify Criteria and Constraints

Criteria and Constraints included Price, Accessibility, Ease of Installation, Precision, Maintenance, and Safety. These were the constraints found in the problem statement and seemed to be the most measurable constraints.

5. Explore Possibilities

We worked with sonar in depth, by designing an arduino system to detect corn. This functioned well, but with further research we found that a sonar stretching 130 ft would cost thousands of dollars. We did research and contact mentors about laser technology and found the dust in the bin would render the laser unable to function. We went out to the MFA grain bins and tested frequencies and stud finder technology on their bins, but neither posed possible. The bin while tapping did not emit enough of a sound to detect and stud finders cannot function on the corrugated surface. The simple pulley system posed most effective.

6. Select and Approach

We chose a pulley system to measure the grain. The farmer would unreel the pulley and the weight would drop inside. We were still uncertain about the measurement system and how the farmer would learn the height, but the pulley design was chosen.

7. Develop a design Proposal

We sketched and discussed for quite a while on the white board, but decided to have markings on the bin and on the rope to measure. The bottom of the pulley is attached to a crank secured to the ground.

8. Model of Prototype

Our first prototype was 3d printed with a thread as a rope. The prototype was crudely assembled at first and the second was pieced together much nicer, with the pulley attached correctly and the vent assembled cleanly.

9. Test and Evaluate

We tested the weights we decided on with a rope over a banister and found it to be much too heavy. 7lbs was decided on after that lab for our device.

We also tested the first prototype we had created and found it to be incorrectly marked, so after a revamp of the device prototype, including new measured marking, the device was fully accurate in measuring the grain height.

10. Refine

We changed the design of the weight to be a cone shaped, easier to escape from the grain. We also changed the design of the crank to be able to be used with a drill instead of a hand crank. The final change was to weatherproof the rope to allow for longer use of the device.

11. Create or Make

We are unable to actually create the device due to monetary and access constraints. There are no bins in our area we can attach it to due to liability reasons.

12. Communicate Results

This website, along with our final presentations at Ameren, Schneider Electric, and in class are the communication of our final project.

Process Reflection

If time warranted, we would secure permits to test our device on full scale grain bins. We would test the weight design under actual pressure of grain or other farm products. We would test our weatherproof rope under weather conditions such as rain and wind. We would test the chosen paint types under weather conditions. We would test the strain on the bin and on the vent roof due to our pulley system. We would test the carbiener strength on how well it will hold the rope to the crank. We would then pitch the idea to John Deere.