CTI's Ewing Grinder is designed to be assembled in minutes and can be cleaned equally as quickly. Capable of making peanut butter, cocoa butter, maize or millet flour, and dozens of other products, CTI's multi-crop grinder opens new opportunities to pursue microenterprise for smallholder farmers. Alternative enterprise opportunities are incredibly valuable, allowing families to gain an income, empowering women to participate in economic life, and contributing to food security by increasing incomes and local food production. One of the most frequent requests we get about the grinder is to add solar motorization, increasing the production potential a grinder can give to a smallholder in areas where electricity access is not available.

As part of CTI's human-centered design process, we are committed to only introduce motorization to our tools where it is contexually and culturally appropriate for the farmer and when CTI has fully determined that motorized solutions will be long-lasting and sustainable. As part of this effort, we reached out to the 
University of Illinois at Urbana–Champaign's engineering department to assist with preliminary testing. Get an inside peak into the work being done from one of the hard working University of Illinois students, Lydia Tanner.

Solar Project Update
Hello! My name is Lydia and I’m a member of a Senior Design group from the University of Illinois at Urbana-Champaign. Within our major, it is required that all students take a course called ABE 469 – Industry-Linked Design Project where we get put into groups and work with an industry partner to get experience working on real-world problems/projects. Me and my four teammates, Hitarth, Shean, Sam, and 
Jeremy, have been working with CTI for the past few months on determining what it would take to solar-power the Ewing VI Grain Grinder.
Students Working in Shop
Our progress thus far can be split into three major steps: 
1)     Determining the design requirements
2)     Researching parts
3)     Choosing a design

All three of those steps have been completed, and we are now be entering the final two stages of this project (assuming no major unforeseen problems!):

4)     Ordering & assembling parts
5)     Testing & write-up

For now, I’ll be describing the first three steps!

Step 1 – Determining the design requirements
After receiving an Ewing VI Grinder from CTI (thank you, btw!), we needed to test the torque requirements in order to spec for parts. To do this, we had a wrench socket built on to the grinder’s shaft so that we could use a torque wrench to perform the grinding. We sourced dent corn locally (a tougher grain than what the grinder is typically used for, which we were informed was pearl millet) in order to determine the higher range of torque required to start the grinding motion. We also tested the torque requirements of soft red winter wheat to be safe. The maximum torque we measured was 25.2 N-m.

Step 2 – Researching parts
So from the first step, we determined that the torque requirement we would need to spec for was 25.2 N-m. From CTI we already knew that the maximum RPM the grinder could handle before incurring damage was 300. In addition, we knew that the shaft diameter of the grinder was 20 mm. And so at this point we started looking for parts that could connect to the shaft and could meet those requirements. This research led to two designs, which I will describe in Step
3. But first, I’d like to address a couple of questions that may have come up at this point in our process.

Why did we test for torque rather than power requirements? We thought torque was the more important requirement, since it more accurately reflects the initial movement of the grinding motion. Power is a function of both torque and RPM, and thus is a measurement that takes place over a period of time. Torque, however, is the force applied on a moment arm (a distance), and thus can be considered an instantaneous measurement, if you will. To motorize the grinder, we need one that can overcome the initial, instantaneous torque. Once the grinding has started, the torque requirement decreases, which is more in-line with a power measurement.

Why does the shaft diameter of the grinder matter? The grinder shaft has to be connected in some way to the rest of our design in order to motorize the grind. Some difficulty we encountered here though is that the shaft diameter is in the SI Unit system, while most of the parts we could realistically order within a certain time-frame are all in the American-adopted English Unit system.

Step 3 – Choosing a design
As stated earlier, we came up with two designs to choose from. Below are images from one of our class presentations that depict them.


Our first design prioritizes safety (since all the parts would be self-contained, thus minimizing the exposure of moving parts to the user) and ease of assembly (since everything is attached in a linear fashion, mounted onto a single base in order). However, the parts are more expensive overall due to the gear box (also known as a speed reducer). The cheapest we found, which did not provide an adequate output torque for our design anyways, was too expensive. In addition, the gear box we did end up finding required ¼ hp input, which required a motor that needed a 24 V input, thus increasing the solar panel requirements from our initial 12 V estimate.


The second design, based off the motorization manual we received from CTI, is essentially the exact same thing except instead of a gear box we would be using two gears and a chain to reduce the motor’s RPM and increase its torque, but potentially lead to more slippage of the chain. However, this design is less expensive and the calculated output torque (maximum) and RPMs are more desirable. In addition, the motor requires the desired 12 V.

Design #1

Design #2

Output Torque

33.331 N-m

39.94 N-m

Output RPM

~49 RPM

~180 RPM

After a meeting with Don & Vern, we decided on Design #2 and began ordering parts.

What now?
So that was steps 1-3, and now we are moving on to 4 & 5. We’ve already have our motor, gears, and chain, and are waiting on a bushing in order to fit our gear onto the grinder’s shaft. Researching batteries and consulting professors is still underway, but we hope to order the remaining parts soon and have our assembly complete in the coming weeks, fingers crossed!

Kind regards,
Team Rise N’ Grind 
 Rise and Grind Team Logo

"Team Rise n' Grind"
From Left to Right: Hitarth Patel, Shean Lin, Samuel Sung, Jeremy Martin, and Lydia Tanner
From Left to Right: Hitarth Patel, Shean Lin, Samuel Sung, Jeremy Martin, and Lydia Tanner

Friday, 31 October 2014

What true empowerment looks like

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aissitou1“The business gives me more power in the community.”

Meet Aissatou, a farmer, mother of four, and breadwinner for her family. A few months ago, Aissatou purchased a CTI grinder and began selling grinding services to her neighbors and peanut butter at the market.

Words like “empowerment” get thrown around casually in the nonprofit world, but what does empowering women business leaders really mean?

Well it’s about so much more than reducing drudgery and raising incomes. Women like Aissatou become well respected decision-makers in their communities and influential role models. So while she’s raising their own standard of living, Aissatou is also elevating the status of women in her village and in Senegal.

An interview with Aissatou

Tell us about your village

I am from Lende, a village in the community of Thiargny in Louga region of Senegal. We live 30 KM from the main road, and we have water, but no electricity yet. We are a Pular community, and we mostly work in livestock, raising animals like goats, cows, and chickens.

Tell us about your grinder business

Every Tuesday I go to the weekly market and sell products in the community. Six months ago, I bought a CTI grinder. It’s helped me use my time more efficiently. I provide grinding services to other women, and I sell peanut butter at the market now. Now I can grind about 10 kg of peanut butter a day and sell it at the weekly market, and earn about $1 more each day. I use the money to feed and support my family.

The grinder is simple. It’s durable, I don’t need help to fix it, and I don’t have the face the need to find gas.

I like that, in my community, I’ve been able to find an opportunity to create a business and become self-sufficient.

What are you most proud of?

I’m proud, as a woman, to be a leader and have respect in my community. I’m proud that I don’t need to ask for help, I can take care of my family with the daily work I’m doing: raising my cattle (cows, lams, goats, chickens) and providing grinding services with the CTI grinder I bought. Now I’m proud to sell peanut butter I made with the CTI grinder too.

I am also the 336 member of “PAMECAS,” a microfinance institute operating in our community ten years ago. As one of the first members of the community, I am a board member and can participate in decision making.

What do you do with your extra income?

I have four daughters that go to school, and I use the money to pay for their school fees, and to feed them, and help support my husband, of course. I also save some of the money so I can get more loans from the Micro-finance Institute.
How does it feel to own a business?

It is very important for me to own a business, and now I can use more extra time in a more efficient manner, and the business gives me more power in the community too.

How does it feel to be a woman leader?

It makes me meet with other people and this is important for me. Sometime it can be tough to be a woman leader because within the group we have different ethnicities and different ages—the young and old women have different points of view. But it’s quite interesting because they follow me and trust to me.

What are your hopes for the future?

I hope to see my daughters more educated than me so they can play a role in the community. And, of course, I want my business grow!


Villagers in rural Uganda are becoming small business owners as a result of a partnership between CTI and Village Enterprise (VE), a nonprofit that provides business skills training and support to entrepreneurs in some of the poorest regions of East Africa — in rural communities rarely served by microfinance groups.

In Uganda, VE distributes our grinders to small business groups, providing the groups with training and mentoring in business skills, savings and financial literacy. Recognizing that locals know their communities best, VE encourages the groups to develop their own business ideas. By empowering hard-working villagers with tools, training and support, the collaboration is helping those living in some of the world’s most underserved communities become thriving entrepreneurs.


Monday, 01 June 2009

“CTI in Haiti” Video is Online!

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We’re excited to announce that a new video covering CTI’s partnership with Meds and Food for Kids in Haiti is online!

Spare six minutes for this one; you won’t regret it. View the video here!