Egyptian Shaduf: Difference between revisions

Latest revision as of 10:31, 11 May 2017

Description

A Shaduf (aka Shadoof) is hand-operated simple machine for lifting water to irrigate land still used in India, Africa, Egypt, and some other countries. Typically it consists of a long pole or beam mounted like a tall seesaw. There is a water bucket suspended from one end and a counterweight is positioned towards the other.

In use, the water bucket suspension rope is pulled down to lower the bucket into the water and then lifted out with the aid of the counterweight when filled. In both actions, the top beam serves mainly as a Class 1 Lever: pulling against the counterweight as the bucket is lowered and, as it is raised, the counterweight provides the Effort to lift the weight of water (plus a little extra effort provided by the operator pulling the bucket upwards).

Task

Build a model Shaduf and use it to lift a 1kg mass.
- use Stripwood to build the main frame.
- you may wish to fill part of the lid from a spray can or a paper cup with ‘plasticine’ or similar to make a counterweight.
- the top of a spray can or a paper cup may also be used to model a water bucket.

Testing

How does the Shaduf make it easier to lift the mass?
Does it matter where you position the counterweight?
Should the counterweight balance an empty bucket or a bucket filled with water - or half filled with water?
How heavy would the counterweight be to lift a litre of water?
How might the design limit the height to which pyramid stones could have been lifted in this way?
How would you make a larger model using garden canes for example?

DT Online Buyers' Guide

Structures and Frames can also be modelled using the Construction Kits listed in the Truss Bridges and Looking at Bridges articles.

Safety Point! Take great care with hot glue guns and all hot-melt glues. The melted glue can stick to the skin and cause severe burns.


Junior Hacksaw	Clamp-on Hobby Vice	Stripwood	Balsa Wood	Medium card coloured	Thick card coloured	Cutting Mat	10mm Squared Paper	PVA glue	Glue Gun	Bamboo Flower Sticks

Notes:

Choose metal cutting hacksaw blades - the teeth are small which suits this scale of work and they are safer for young children
School PVA glue is best for young children because it is non-toxic and washes off : PVA Wood Glue is strongest but must be used with care.
Try to get natural Flower Sticks or wear gloves because the green stain comes off on hands!

@@ Line 1: / Line 1: @@
-[[File:Shaduf2.jpeg|right|250px|Shaduf|link=https://en.wikipedia.org/wiki/Shadoof]]
+[[File:Shaduf2.jpeg|right|250px|Shaduf|link=http://en.wikipedia.org/wiki/Shadoof]]
 __TOC__
@@ Line 5: / Line 5: @@
 =====Description=====
-A [https://en.wikipedia.org/wiki/Shadoof '''Shaduf'''] ''(aka '''Shadoof''')'' is hand-operated simple '''[[Basic Machines|machine]]''' for lifting water to irrigate land still used in India, Africa, Egypt, and some other countries. Typically it consists of a long pole or beam mounted like a tall seesaw. There is a water bucket suspended from one end and a counterweight is positioned towards the other.
+A [http://en.wikipedia.org/wiki/Shadoof '''Shaduf'''] ''(aka '''Shadoof''')'' is hand-operated simple '''[[Basic Machines|machine]]''' for lifting water to irrigate land still used in India, Africa, Egypt, and some other countries. Typically it consists of a long pole or beam mounted like a tall seesaw. There is a water bucket suspended from one end and a counterweight is positioned towards the other.
@@ Line 14: / Line 14: @@
 =====Task=====
-* Build a model [https://en.wikipedia.org/wiki/Shadoof '''Shaduf'''] and use it to lift a 1kg mass.
+* Build a model [http://en.wikipedia.org/wiki/Shadoof '''Shaduf'''] and use it to lift a 1kg mass.
 ** use '''[[:Category:Stripwood Technology|Stripwood]]''' to build the main frame.
-** you may wish to fill part of the lid from a spray can or a paper cup with  [https://en.wikipedia.org/wiki/Plasticine ‘plasticine’] or similar to make a counterweight.
+** you may wish to fill part of the lid from a spray can or a paper cup with  [http://en.wikipedia.org/wiki/Plasticine ‘plasticine’] or similar to make a counterweight.
 ** the top of a spray can or a paper cup may also be used to model a water bucket.
@@ Line 22: / Line 22: @@
 =====Testing=====
-* How does the [https://en.wikipedia.org/wiki/Shadoof '''Shaduf'''] make it easier to lift the mass?
+* How does the [http://en.wikipedia.org/wiki/Shadoof '''Shaduf'''] make it easier to lift the mass?
 * Does it matter where you position the counterweight?
-* Should the counterweight balance an empty bucket or a bucket
+* Should the counterweight balance an empty bucket or a bucket filled with water - or half filled with water?
 * How heavy would the counterweight be to lift a litre of water?
 * How might the design limit the height to which pyramid stones could have been lifted in this way?
@@ Line 34: / Line 34: @@
 [[Category:Primary]]
+[[Category:Topics, Projects and Tasks]]
 [[Category:Ancient Egypt]]