Posted by Kwami Williams, Scale-Ups Fellow, August
It’s crazy to realize that I’m more than half-way through my time in Ghana. Actually, today marks three weeks since I landed in Ghana. The time has flown by so quickly and I’m asking myself where it has all gone. I guess the saying “Time flies when you are having fun” is very applicable here. But ‘fun’ here isn’t just the euphoric experience you get from riding a roller coaster but rather the encapsulation of high points, low points, successes and disappointments. So perhaps for me I would phrase it, “Time flies when you are having an adventure.”
And an adventure it has been, from last-minute breakthroughs with the hydraulic jack oil press design at 3am the day I flew out of Boston to Ghana, to bartering for a better price in Twi (a language I understand but struggle to speak). But I must say the adventure has been great!
Things have been progressing pretty well, though with lots of wonderful hiccups. I left MIT with the dismantled parts of a functioning device that cold-pressed moringa seeds using a hydraulic car bottle jack at about 70% efficiency.
I also left with plans to incorporate feedback we received on a device that shells moringa seeds. The sheller was built as a project this past January during IAP by Emily Cunningham and Maysun Hasan (members of the Ghana Team from D-Lab Development) and members of the Intermediate Technology Transfer Unit (ITTU) of Kwame Nkrumah University of Science and Technology (KNUST) here in Kumasi, Ghana. I had a list of partners and potential partners to meet with, questions to ask, detailed itinerary and by God’s grace, I have seen these plans become reality.
Over the past three weeks, I’ve been able to work with members of ITTU, especially Mr. Francis and Mr. Suleiman to build and test two iterations of the Moringa Sheller and the current design is just wonderful (below).
A central goal of mine in incorporating the feedback we received during IAP was to modify the sheller in a way that would allow more of the shells to be separated from the seeds during the shelling process. This would decrease or eliminate the need to winnow after shelling. Prototype 2.0 (left) attempted to mechanize the winnowing process with the addition of the rectangular basket beneath the shelling drum and tie that into the main shelling process using bike parts. It worked but in the second stage, the shape of the rectangular basket didn’t allow the seeds to tumble enough for the shells to fall out through the perforated material. God then gave me the idea of building the main drum out of the same perforated grill material and voilà, Prototype 3.0 (right) was conceived J. It works extremely well; it not only shells faster than the previous prototype but also allows all the removed shells to fall out during the shelling process. It’s also cheaper than the previous prototypes and easier and faster to make. It has been great to see how each iteration of the design has really helped move the device forward.
The oil press has been the more challenging piece to work with. I left the U.S. having gotten a significant amount of oil to flow after a long day and night of building with Jack Whipple, Roberto Melendez, Kojo Welbeck, and Jeffrey.
Then, after a few days of building at ITTU, we converted the bolted design (above) to a lighter welded design also incorporating feedback from my meeting with Bob Nanes (Ghana Country Director- IDE). And there was oil flowing. Yay!
The efficiencies were lower than I recorded and so I spent the rest of my first week troubleshooting that and correcting a lot of the misalignment that had been introduced from welding the parts together.
D-Lab instructor, Gwyndaf Jones, relieved my frustration when he pointed out that the cylinder I was using was double the area of what I had tested with thereby halving the pressure and lowering the efficiency with which the oil was pressed. It was one of those instances of being so caught up in the project that I overlooked the impact of a simple, but ultimately crucial, change. More tests led to a bent and broken frame in Week 2:
Then beefed up the frame: Tried to re-aligned things throughout the week . . .
. . . but now not only was the oil coming out. the seedcake was also being extruded out.
I tried a host of things to understand why the problem was occurring and attempted to fix it. The funkiest solution was making a plate that used a spring to press the cylinder firmly during the oil pressing process:
Fun to make and test but it didn’t solve the issue. After testing each component (seed container cylinder with and without slits, smaller and larger solid cylinder diameter, with and without the spring plate, different and no oil collector plate the cylinder sits on, alignment of mating parts, amount of seeds), I had only the frame to eliminate as the variable leading to the seed extrusion. Incorporating feedback from visiting Paul Yeboah (Ghana Permaculture Institute & Lush Logistics Coordinator), and Mr. Ahima (accomplished farmer and expert) and Chris Schlemp (Peace Corps volunteer), Prototype 3.0 was completed in Week 3:
The major changes were building entirely out of much stronger U channel (which I got drastically overpaid for — 30 cedis—but I learned I should have paid 15 cedis at most), scaling the jack from 6 tons to 10 tons, and making the frame taller to allow for more seeds to be pressed per use. Mr. Appiah, a welder/fabricator/engineering guru at Suame Magazine also came up with the idea of recessing just the cylinder wall in the plate the seed container cylinder sits on.
These changes, and Mr. Appiah’s plate idea, have caused Prototype 3.0 to perform significantly better than 2.0 and the amount of seed cake being extruded has been greatly reduced. Each partner I’ve met has given me ideas on solving the seedcake issue and improving the efficiency of the device, so I’m excited to return and implement their suggestions.
Building at Suame Magazine and ITTU has been exciting. It is simply amazing to see what my friends here can do with nonexistant, malfunctioning, or poorly maintained tools. And they really have become friends now; we eat together, laugh, design, disagree, listen to music and talk radio, talk about life, and laugh at my poor Twi . It has just been amazing to see the warmness of Ghanaians expressed in sacrificial service and support to me. Mr. Francis, Mr. Suleiman, Boakye, Bonifacio, Mr. William, Mr. James, Mr. Crossman (ITTU staff), Mr. Appiah (Suame) have been an incredible blessing and without their expertise none of the iterations we’ve built would exist.
Building at ITTU has taught me a lot about fabricating with limited resources. The tools we’ve had access to has dictated some of the material choices we’ve made. It’s been difficult to make things straight and I have had to spend a lot of time redoing/modifying things as a result. Drilling things has been adventure. The lathe’s need a master’s touch, mainly Mr Francis or Mr. Appiah. And yet still, anything you want to build somehow materializes- the magic of ITTU and Suame!
More than just tools and material availability have affected my work in Suame. Building slows when Mr. Suleiman leaves to pray at the mosque. It’s been great to see how seriously he takes his faith. Each person has work of his own to complete. ITTU technically closes at 1pm in the summer, they’ve stayed longer for me, but it certainly isn’t the 5pm (sometimes later) closing times I enjoyed in January when I was last here.
Mr. Francis, the main person helping me, was hit in the eye by the shrapnel from an exploding angle grinder disk about a week before my coming so he has had only one good eye. Lack of safety equipment and safety consciousness on my part actually caused me extreme pain. For over two days, my eyes hurt terribly from over-exposure to the light produced during welding. My eyes watered when there was any white light, open or closed they hurt badly, sleeping was a challenge, but I’m all better now by God’s grace.