Manual compactor #5: testing in the field

When we started designing a manual plastic bottle compactor for our services in Maputo, we didn't have engineering software, material calculators, or a testing facility. What we had was a courtyard, basic welding equipment, and the hands on knowledge of people who work with waste and metal every day.

Our approach was simple: build it with the cheapest material readily available in Maputo, test it, observe limitations and operating challenges, and find and implement a solution. 

We started small, with a cardboard prototype to test the compaction principle using a lever, then we used the thinnest steel sheet available. Every time we increased the size of the prototype, new problems appeared. Sides bending under load. Top plate deforming. We always reached for the thinnest, cheapest material first, not to cut corners, but because the compactor has to be affordable and repairable in Mozambique, with materials you can find at the local market. Ultimately, it is also crucial to keep the compactor as light as possible, to be easily carried around, moved on and off the truck and set up.

The 40×40cm was the first version built with 1.6mm steel, a step up that came directly from watching the thinner sheets bend under real loads. We reinforced the top plate with 8mm construction rebars.

This was the first version we brought to a collection point, testing not just whether it could compact, but whether one person could set it up, use it, and dismantle it in real conditions and reasonable time.