Appropriate Technology Technical Notes describe simple, small-scale technologies aimed at improving people's access to food, water, and shelter. Each document introduces and explains the general concept behind the technological solution, some even include instructions of how to construct your own.

14 Issues in this Publication (Showing 1 - 10)

Treadle Grindstone - 2010-01-01

This treadle grindstone can spin a 6” abrasive wheel (of the type used on electric tool grinders) at up to 3000 rpm by means of a single treadle operated by the person using the grinder. Although rotational speed is similar to electric grinders, power is lower therefore short or light grinding passes must be taken. This tool may be a good addition to a shop where electricity is not available. 

What’s Inside:

  • Operating the Grinder
  • Maintenance
  • Disassembly
  • Drive Rope
  • Direction of Rotation
  • Improving the Grindstone
  • Grinding Wheel Speed
  • Dimensioned Drawings

PVC Water Pumps - 2010-01-01

The purpose of this document is to show several water pump designs constructed from PVC pipe, explain how to manufacture them, and discuss pump performance and how to improve on these designs. 

What’s Inside:

  • Pump Design
  • Manufacturing Process
  • Pump Performance
  • Appendix

TN #55 A-Frame Level - 2006-01-01

The A-Frame Level is a simple, yet accurate tool used for constructing contours on a hillside or slope. It is useful in the basic construction of hillside farming systems, such as the SALT systems, as well as for establishing level contours and drainage ditches. Level contours on a slope reduce erosion, increase water infiltration, protect slopes and facilitate reclamation of degraded hillsides. The A-Frame Level can also be used to determine the percent slope of a hillside. This document provides the basic instructions for constructing and using an A-Frame Level.

What’s Inside:

  • Materials for Construction
  • Assembly of A-Frame
  • Calibration of A-Frame
  • Marking Contour Lines
  • Measuring a Slope
  • Useful Resources 

Rope Maker - 2003-01-01

Rope can be made from cord or string or even discarded plastic bags using a simple spindle to twist the materials together. 

TN #88 How to Build a Kerosene Fired 180 Egg Incubator with 12V Air Circulation - 2003-01-01

Although this document will tell you how to build a particular incubator that I have used for several years, the ideas presented here should assist in building an incubator of any capacity. The orientation here is toward solving the problems in building a kerosene fired incubator in general. Furthermore, artificial egg incubation requires three pieces of equipment: the incubator, a hatcher, and a brooder. This document only covers the incubator I use, the bottom part of which could be used as a hatcher but ideally a separate hatcher should be used. Once hatched, the chicks need to be kept warm at 32° C (90° F) for two weeks or more in a brooder. Presumably the reader is already familiar with the brooding phase of chick raising as that is where most folks begin: with day old chicks from a hatchery. Before investing too much time and effort in construction you need to know this incubator requires good carpentry skills, preferably a table saw, and battery powered drill / screw driver. You will have to have access to acetylene welding equipment or someone who can fabricate for you the fuel tank and chimney. There are a number of items that may be hard to get other than from the sources I used in USA cited at the end. Building this incubator takes me a month. Finally, my hatches run 40 – 60%, below the 70 - 80% a good incubator should produce but comparable to my hens’ performance. 

What’s Inside:

  • Introduction
  • Step -by-Step How to Build
  • Incubator Operation
  • Hatching
  • Conclusion
  • Source of Materials

TN #87 Seed Drying Cabinet - 2002-01-01

Seed storage is often a problem in the tropics. However, if seeds can be properly dried, they will remain viable for a longer period of time. The seed drying cabinet described here can help improve the viability of seeds in storage.

What’s Inside:

  • Introduction
  • Description
  • Diagram
  • Observations

TN #86 Forage Cutter - 2002-01-01

This simple forage cutter provides a mechanism to chop tough grasses or other forages to make them more palatable and digestible for livestock. This results in more efficient food conversion for animals and reduced wastage. It can also be used to chop materials for compost, silage, vermiculture, etc.

What’s Inside:

  • Introduction
  • Materials
  • Description

Composting Toilets - 2002-01-01

A composting toilet is any system that converts human waste into compost through the natural breakdown of organic matter. The photo above shows a composting toilet from the late 1800’s. Composting toilets provide a sanitary method to recycle human waste while conserving water and protecting the environment. In addition, they produce a valuable fertilizer. Composting toilets can be divided into batch systems and continuous use systems. The models covered here are batch systems. 

TN #43 BioSand Water Filter - 2001-01-01

Access to clean drinking water remains one of the greatest challenges in the world. The BioSand Filter is one method that can be used for purifying water at the household level. With this filter, contaminated water is filtered through a natural biological layer and then layers of sand, pebbles and stones. The BioSand Filter can be made using local materials and is a low-cost system that removes suspended sediments and other impurities from water in order to make it safer for human consumption. 

What’s Inside:

  • Household Water Treatment
  • Filter Details Materials for Construction Filter
  • Construction Filter Assembly
  • Filter Use Filter
  • Maintenance Additional Resources 

Haybaler - 2001-01-01

This simple device provides a method of manually producing bales of hay. Small-scale farmers may be interested in this technology because hay is both easier to store and easier to transport when it has been baled. Also, baled hay retains a higher nutrient content than hay that has been cut and left exposed to the sun.