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Description

Wheels, drives and bearings, as part of an engineering system to facilitate small scale agriculture for the poorest farmers.

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Wheels to ease a peasants burden
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Ready for testing in practice Hundredfold reduction of cost Applicable within poverty Income Nutricion Rural



Why
Mechanization may lighten the peasant's burden when it can be achieved without significant cost. For mechanization of agricultural work, wheels are the most crucial parts. The function of wheels may differ, but whether large or small, tools and means available at a peasant yard should suffice for their construction. The size of the big wheel in a drive also depends on how small the smaller wheel can be constructed to guarantee proper power transmission. As a chain drive, V-belt or tooth belts can not be applied, other means of transmission have to be found.

How
Experiments are carried out to find an effective method to construct drive wheels for agricultural devices, such as wind drives and water wheels. The focus is on a method of construction that is applicable at a peasants yard while its method of construction is easy to teach and highly functional as well. The big wheels are composed out of sticks of exactly the same length, the small wheels are constructed from wooden board with a V-notch, grouped around a wooden axle. The drive element is simple sisal rope that has proved to be able to transmit the required torque.
The largest effective drive diameter made with sticks is about 2 meter, the smallest made with a rubber disk is 55 mm.





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  • Rethinking Rural Development
    Mechanization of heavy manual work is a factor in rural develoment. But other factors matter as well. For more general infomation on Rural Development go to:
    http://www.demotech.org/d-publications/designB.php?sub=232
  • Send us an email form about any relevant link, that should be added here


  • What other people say...

    If you like you can add your own comment

    by Reinder van Tijen - Sat Dec 07 (2002)
    Wheels to ease a peasants life
    (image/pjpeg) Working on The Wheel
    Today, the 1st of August, Hans Baarslag and I worked on the problem how to make a stable wheelhub for a wheel made out of sticks. We tried to realize the following specifications :
  • 1 Interconnection of sticks with rubber strips cut from the side wall of a car tire. In strips or smaller rectangular pieces, round holes are punched.
  • 2 The size of the hole is a it smaller that the diameter of the stick, to ger a firm fit.
  • 3 At the center, the place where the tangential sticks should touch the wooden axle, these sticks should indeed be positioned to touch AND be tangential.
  • The assembly of sticks around the axle (call it het hub), has to be in a stable position re. the rest of the wheel, i.e. not be able to turn slightly.
  • The way to achieve this stabilisation has to clear, simple and effective Look at the pictures: ? A former experiment used a wooden block to which the rubber hub strips were attached. This block was not easy to make and its making would be hard to explain. However the stabilizer itself functioned well. The rubber strips could sag out of line, then the sticks could slip further through, making the hub less stable.
  • A detail of the stabilization block. It is attached with 2 ropes to the wooden axle. The block can rotate around the axle, but remains firmly in an axial position.
  • To realize the above specifications, we have made rubber hub strips with holes for the tangential sticks. Extra are added now similar holes for short sticks that are mounted paralel to the axle. The photo shows how one of thes sticks is inserted in both rings.
  • by Hans Baarslag - Sat Dec 06 (2003)
    wheels
    Reinder ,I think you have now a very good way of making light,stable big wheels. Among others to be used as driving wheel for rope pumps using the smal piping. It is now a question of pictures and a good explanation to explain this to others.
    Remains a question: Is bamboo or a replacement readily available in africa? And how can we spread the good news?

    by Reinder / Demotech - Fri Oct 31 (2003)
    Re: wheels
    Indeed, the method of making large diameter wheel seems satisfying, but has to be properly tested on a testbed. In our new Maastricht workshop, this has still to be set up. It will take at least a few months before its value can be regarded proven. So as yet, no good news to spread! Bamboo could in principle replace the plastic pipe. However I expect the plastic pipe to be cheap enough to make a low quality solution superfluous.

    by reinder / Demotech - Sat Dec 02 (2006)
    Re: wheels
    For making the wheel it is not important that the stick are as straight as bamboo. Only the length and the place where the little interconnection holes are punctured do matter. So more or less straight wooden sticks can be used as well.
    Not easy to make this construction idea popular. I'll introduce it in a field trial first, when people like it, I may shout out a little louder!

    by Hans Baarslag - Sun Dec 04 (2005)
    wheels
    Wheels to ease a pesants burden is too long and too general. What about wheels from sticks or sticky wheels. Or foldable wheels. Donckey drive wheels. Hans

    by Reinder / Demotech - Fri Oct 31 (2003)
    Re: wheels
    The name is OK. This design issue is indeed about to make the peasant's burden lighter by offering engineering elements, that be made locally with little effort and little or no cost. Wheels, whatever they are made off, are such elements. It took plenty effort to work out a proper way to made a larger size, to make the small wheels also was difficult enough. In their present state of development, they should be described here as well.
    What has to be added as well are the fittings for ball bearings as well as many other engineering elements Demotech has some experience with. Given time or given assistance with web publishing, all this will become available here!
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