Funicular Polygon and Forces Apparatus

Low cost, effective teaching

Self-contained, bench mounted

Direct measurement of forces

Adjustable lines of action of forces

Practical verification of triangle of forces, polygon of forces and link polygon

Demonstrates equilibrium of forces at a point, applied to      various points round a
   disc or acting on a rectangular lamina

Concurrent & Non-concurrent coplanar forces

Three year warranty

Range of Experiments

1. To resolve by experiment any suitable system of static coplanar forces which may or may not be concurrent
2. To verify graphically using: 
   a) triangle of forces for three concurrent coplanar forces 
   b) polygon of forces for more than three concurrent coplanar forces 
   c) link polygon for three or more non-concurrent coplanar forces
3. To investigate (c) for either a disc or a rectanglar shape
4. To compare the accuracy of the experiment by comparing the experimental and graphical results

Description

This apparatus is a more comprehensive and versatile version of the HFC2. A simple but elegant demonstration of the conditions of equilibrium for three or more coplanar forces acting either at a point, on a circular disc or on a rectangular shape. Up to five loads can be applied to the chosen shape by setting up pulleys at various angular positions. The lines of action of the forces are recorded by drawing along the weighted cords onto a piece of paper attached to the pulley table. A range of experiments is possible, investigating concurrent and non concurrent coplanar forces acting on simple shapes, comparing the experimental values with the relevant polygons of force.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Shearing Force Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Direct measurement of Shear Force
• Loads and supports can be placed in
  any position
• Visual practical verification of the
  concept of Shear Force
• Allows investigation of stability and
  influence lines
• Reinforces concept of equilibrium of vertical forces & moments
• Three year warranty

Range of Experiments

1. To comprehend the action of shear in a beam
2. To measure the shearing force at a section of a loaded beam, and to compare with a theoretical estimate
3. To study the definition of an influence line for shear force

Description

A length of material supported horizontally and carrying vertical loads is called a beam. The loading causes bending and transverse shearing. The loads and reactions are the 'external' forces acting on the beam. They must be in equilibrium. However, the strength of the beam depends on 'internal' forces. This experiment demonstrates the nature of these internal forces and their dependence on the external system of forces.

The experimental beam is in two parts, joined by a pair of ball bearing rollers running in flat vertical tracks. To develop the internal beam forces at the section an underslung tension spring is used to resist the bending moment, while an overhung spring balance provides the vertical shearing force. Due to the mechanical arrangement, there must always be a net downward load on the longer side of the split beam.

The beam is simply supported on end bearings and several weight hangers can be attached at any position on either side of the joint. A hinged metal strip is available to simulate the loading pattern of a panelled girder for a more advanced experiment on influence lines.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results. 

  Bending Moment Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Experimental determination of bending
  moment at a beam section
• Loads and supports can be placed in
  any position
• Visual vertification of the nature of
  bending moment
• Allows investigation of stability and
  influence lines
• Reinforces concept of equilibrium of
  vertical forces and moments
• Three year warrant

Range of Experiments

1. To comprehend the action of moment of resistance in a beam
2. To measure the bending moment at a section of a loaded beam and to compare with a theoretical estimate
3. To study the definition of an influence line for bending moment

Description

A length of material supported horizontally and carrying vertical loads is called a beam. The loading causes bending and transverse shearing. The loads and reactions are the 'external' forces acting on the beam. They must be in equilibrium. However, the strength of the beam depends on 'internal' forces or moments. This experiment demonstrates the nature of these internal forces and their dependence on the external system of forces.

The experimental beam is in two parts, joined together by a pair of low friction ball bearings. An underslung spring balance provides a resisting moment, and also allows the section bending moment to be measured. A hinged metal strip to simulate the loading pattern of panelled girder for a more advanced experiment on influence lines is available.

The beam is simply supported on end bearings and several weight hangers can be attached at any position on either side of the hinge.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Work done by a Variable Force (Tangential Effort)

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Reinforces concepts of work and energy
• Direct reading of tangential effort
• Three year warranty

Range of Experiments

1. To obtain the experimental relationship between effort and distance moved by effort, and to compare with a theoretical prediction
2. To show that the work done is the area under a graph of load against distance moved

Description

This experiment is designed to reinforce the general principle that the work done, particularly by a variable force, can be determined simply by measuring the area under the graph of force and distance moved. The equipment is deliberately simple so that concepts are readily grasped. It is a companion experiment to HFC6, which is concerned with the work done by available vertical force.

A pivoted arm carrying a weight at its end is restrained by a spring balance at right angles to the arm. The angular position of the arm is indicated by a protractor scale.

The effort is the force needed to hold the weighted arm at a particular angle. This can be repeated for several different weights.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Centre of Gravity Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Six different shapes
• Direct location of Centre of Gravity by drawing
• Three year warranty

Range of Experiments

1. To establish the position of the centre of gravity of several different shapes by experiment, and to compare with values derived from calculation or reference books

Description

The centre of gravity of a shape of uniform thickness can easily be found by this method. It provides a simple technique for complicated shapes, far quicker than by using calculus for example, although not producing an accurate answer to the handling of a yacht, the calculation of the moments caused by the wind and water acting at the 'centre of lateral area' of the sails and keel are still used as a starting point.

A free standing backboard has a pin from which a selection of flat shapes can be hung. A simple pendulum suspended from the pin enables the line of action of the weight to be transferred to the lamina. The centre of gravity is the position on the shape where two or more such lines intersect. 

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results. 

  Bell Crank Lever

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• 5 different lever ratio
• Direct readout of reaction by
  spring balance
• Three year warranty

Range of Experiments

1. To determine by experiment the reaction force of a bell-crank lever to an applied load
2. To confirm the effect of leverage ratio
3. To compare with calculation by taking moments about the pivot

Description

Lever mechanisms of all shapes and sizes are very common parts of machines, particularly in hand operated devices. The bell crank lever offers the typical mechanical advantage of a lever, and in addition it turns the line of action of the effort through 90°. In most cases the cranked lever would be a casting with a bushed pivot at the corner. The experimental model has been built up from plastic to simulate the real thing.

This traditional item enables the reaction force of a 90° bell crank to be measured by a spring balance when a load is applied at any of five leverage ratios.

The bell crank is supported on a bushed pivot.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Centrifugal Force Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Wall mounted
• Speed, rotating mass, and radius of
  gyration independently variable
• Direct readout of centrifugal force by
  spring balance
• Direct readout of rotational speed by
  digital tachometer
• Fully guarded
• Three year warranty

Range of Experiments

1. To verify that the centrifugal force on a rotating mass is proportional to the:-
   
   
   1. square of the speed
      
   2. mass
      
   3. radius of gyration
      
   
   
2. To compare the experimental results with those calculated from theory

Description

This apparatus is used to verify that centrifugal force varies with the square of the speed, the rotating mass, and the radius of gyration. A unique feature is that all three variables can be set and the centrifugal force directly read from the spring balance. Six masses are supplied. The unit has a built-in variable speed drive and digital tachometer.

The equipment is fully guarded (not shown in the photograph).

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Conservation of Angular Momentum

Features

• Low cost, effective teaching
• Self-contained
• Wall mounted
• High visual impact
• Genuine "hands-on" experience
• Three year warranty

Range of Experiments

1. Used for demonstration only, no measurements are intended. Demonstrates basic concepts of conservation of angular momentum through visual observation

Description

Conservation of linear momentum is well understood and often demonstrated to students. Equally important is the conservation of angular momentum. It is not easy to do meaningful experiments on this, but a highly visual demonstration of almost dramatic impact is the effect of reducing the radius of a rotating mass. This is often seen in an ice skater performing a pirouette. First they spin round on an axis corresponding to their body, arms outstretched. When they raise their arms above their head, the increase in spin in considerable. Rather than go to an ice rink, students can perform this experiments in the laboratory.

A bench mounted vertical board has a rotating arm along which two weights can be moved by a pull cord operated by the student or demonstrator.

The weights are moved to the outer ends of their travel, away from the centre of rotation. The arm is then spun rapidly by hand, and the weights pulled towards the centre by the cord.

The resulting increase in angular velocity is considerable.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Forces Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Wall mounted
• Evaluation of forces in levers and slings
  for lifting heavy objects
• Three year warranty

Range of Experiments

1. Reactions of levers
   
2. Forces acting at an angle
3. Forces at a point
4. Finding centres of gravity

Description

For forces on levers, sling forces, equilibrium forces, etc and particularly suitable for motor vehicle courses. All components for the above experiments are supplied as standard. Five geometric shapes with a simple pendulum can be supplied as an optional extra for centre of gravity experiments.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Three Wire Suspension Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Direct measurement of horizontal reaction
• Angle of toggle variable
• Demonstrates application of velocity
  diagrams
• Three year warranty

Range of Experiments

1. To study the vertical equilibrium of a two and three wire suspension system
2. To examine the action of the central vertical redundant force

Description

A free standing backboard provides supports for three tensile suspenders that meet at a ring carrying a load hanger. Spring balances measure the tension in each of the suspenders which are at about 30 and 45 degrees to the central vertical one. The lengths of each suspender can be adjusted by a threaded rod attached to the spring balance.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Toggle Joint Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Direct measurement of horizontal reaction
• Angle of toggle variable
• Demonstrates application of
  velocity diagrams
• Three year warranty

Range of Experiments

1. To determine the experimental horizontal reaction due to loading
2. To compare with theoretical predictions, such as the velocity diagram technique
3. To assess the effect of the toggle angle

Description

This apparatus is designed to evaluate forces within a toggle mechanism. Load is applied to the two pairs of links by a hanger suspended from their connecting pivot. One end of the links is pivoted to a base, and the other end is able to move sideways on low friction ball bearing wheels. The moving links are restrained by a horizontal spring balance, which measures the horizontal reaction directly. The angle of the toggle can be varied. Adjustment is provided for returning the geometry of the loaded toggle to its original unloaded state before taking measurements. The supporting blocks are not supplied.

There are many ways in which the forces can be determined theoretically. The instruction sheet provided with the apparatus takes the opportunity to introduce the use of velocity diagrams to solve essentially static problems by considering virtual motion. However, other techniques can be used if desired.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Shear Legs

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Direct measurement of strut and backstay forces by spring balance
• Three year warranty

Range of Experiments

1. Experimental determination of forces in shear legs
2. Comparison with theoretical prediction
3. To assess the effect of changing the shear leg geometry

Description

Shear legs are often used to make temporary cranes. In this experiment the ideas developed in experiments with several forces in one plane are extended to three dimensions. Clarity of thought is encouraged, since there are both compressive and tensile forces present.

The double shear legs are mounted on rollers which run on a round bar. Compression forces in the legs are measured with integral spring balances, and restraint is by an adjustable tie chain. The back stay is adjustable and is also fitted with a spring balance. Loading is by a weight hung from the apex.

The unit is free standing on a bench top.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Tension Coefficients Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Wall mounted
• Direct reading of jib and tie loads using spring balances
• Demonstrates the application of tension coefficient to evaluate forces in three dimensions

Range of Experiments

1. To determine experimentally forces induced in individual frame members
2. To calculate the theoretical forces induced, using the method of tension coefficients
3. To compare the experimental and theroretical results
4. To repeat for other frame configurations

Description

The apparatus consists of a jib restrained by two chain ties making a triangulated three dimensional structure. The jib and both ties are fitted with spring balances so that the internal forces can be measured.

The bottom of the jib is pivoted to the wall mounted plate and the tie attachment locations can be varied independently at their wall ends.

A load is hung from the jib end, and the geometry returned to its unloaded state using a knurled collar before taking the spring balance readings.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Rubber in Shear Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Wall mounted
• Range of pivot angles supplied
• Optional bearings available
• Determination of modulus of rigidity and Poissons Ratio
• Three year warranty

Range of Experiments

1. To determine the variation of deflection with applied load
2. To investigate the relationship between shear stress and shear strain
3. To find the modulus of rigidity of the rubber block

Description

Rubber blocks in shear force are often used on engine and in equipment mounting to isolate vibrations. They do this by absorbing shock energy by deforming. This deformation leads to a decrease in cross-section as the block lengthens, an effect described by Poisson's Ratio. After this experiment, students will understand the behaviour of a very flexible material such as rubber. Rubber is interesting in that the lay person regards it as an 'elastic' material. In engineering terms it is not as 'elastic' as steel and often exhibits a high degree of hysteresis.

A rubber block 150 x 75 x 25mm is bonded to two aluminium alloy plates. One plate is screwed to a wall, whilst the other has a shear load applied by a loaded weight hanger. A dial gauge measures the deflection of the block.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught.

A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Basic Roof Truss

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Truss angle can be varied
• Direct read out of strut and tie forces by spring balances
• Three year warranty

Range of Experiments

1. To compare experimental values of the forces in the struts and tie of a basic roof truss with theoretical predictions
2. To observe the effect of changing the tie bar length

Description

The basic roof truss consists of two rafters or struts and a restraining tie. Both rafters are pivoted at their apex. The other end of one of the rafters is pivoted to a free standing base, whilst the remaining rafter end runs on ball bearings along a track. When a load is hung from the apex, the free end of the rafter moves sideways, restrained by a spring balance tie.

Both rafters also include spring balances so that all internal loads can be directly measured.

Re-adjustment of the geometry back to its original unloaded configuration is easily made before taking measurements. The length of the tie can be varied to change the angles of the truss.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Derrick Crane

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Direct readout of jib and tie loads by spring balances
• Demonstrate principles of equilibrium and polygon of forces
• Three year warranty

Range of Experiments

1. Determination of forces in the crane members
2. Comparison with prediction by the polygon of forces
3. Demonstration of equilibrium of forces

Description

This apparatus represents the forces in a simple crane and introduces the student to equilibrium of forces and solution by the triangle of forces.

The crane is mounted on a base designed to be stood on a level bench.

Both the jib and tie include spring balances for measuring the internal forces. A load is hung from the end of the jib.

Re-adjustment of the crane geometry back to its original unloaded layout is possible by a knurled adjuster on the jib and adjusting the links of the chain.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Work done by a Variable Force (Vertical Effort)

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Reinforces concepts of work and energy
• Three year warranty

Range of Experiments

1. To determine the work done by a variable effort and to compare with the work done in lifting the load
2. To show that the work done by the effort is equal to the change in potential energy of the load

Description

This experiment is designed to reinforce the general principle that the work done, particularly by a variable force, can be determined simply by measuring the area under the graph of force and distance moved. It forms a comparison experiment with HFC7 which is concerned with the work done by a variable tangential force.

The experiment is deliberately simple so that theoretical comparisons are easily made. It forms a good introduction to simple machines, leading to later studies on machine performance.

The apparatus is a simple lifting mechanism with obvious non linear characteristics. A suspension cord carrying a loaded trolley at mid span is tensioned by passing the cord over a pulley at one end and down to a weight hanger. As the vertical effort is increased, the tensioned cord will move to a new equilibrium position lifting the loaded trolley. Heights of the load and effort are measured relative to the base.

All the pulleys are fitted with ball bearings to minimise friction effects.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Simple Moments Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Demonstrates concept of moment
  equilibrium
• Three year warranty

Range of Experiments

1. To apply a stable system of loading to a pivoted beam
2. To compare with values obtained from calculation using simple moments

Description

This equipment provides a simple easy to understand experiment on the equilibrium of moments. Several loads can be put on the beam at various positions. These will make the beam rotate. The student has to determine the moment necessary to overcome this rotation and keep the beam level. On a practical level, this principle is used in the measurement of goods, such as in chemical balances and steelyards.

The alloy beam is 530mm long and graduated in each direction from the central pivot in cm. Three wire stirrups, weight hangers and a set of weights are included.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Wall Jib Crane

Features

• Member forces all directly measured
• Rapidly variable configuration
• Wall mounted
• Folds flat to the wall
• Three year warranty

Range of Experiments

1. Comparison of measured forces with a triangle of forces and theoretical values
2. Comprehension of the action of the crane cable forces on the jib and the effect of the jib inclination

Description

Although wall jib cranes are obsolete, the self evident confluence of the four forces at the end of the jib illustrates the application of a triangle of forces so clearly to a real situation that this is an invaluable lesson.

This wall mounted self-contained jib crane has spring balances built into its two members. After loading the member lengths can be adjusted to their no-load lengths. The jib out-hang and the crane cable inclination can be readily changed. An instruction sheet is provided.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Acceleration Apparatus

Features

• Self-contained
• Bench mounted
• Novel gliding design
• Total mass of moving system can be kept constant for different acceleration masses
• Acceleration determination by spark generator and electro-sensitive paper
• Confirmation of Newton's Second Law
  of Motion
• Determination of gravitational acceleration
• Three year warranty

Range of Experiments

1. To show that a force causes a mass to accelerate, and that the acceleration is proportional to the force
2. To compare experimental and theoretical values of forces required to accelerate a given mass
3. To determine the acceleration due to gravity, g

Description

This type of equipment has been used for many years to introduce students to accelerated linear motion, in particular the dependence of the acceleration on the net force causing the motion. Confirmation of Newton's second law of motion and the determination of gravitational acceleration are possible.

The trolley which carries five removable masses glides on two rails attached to the base.

Electro-sensitive paper strip attached to the trolley passes through a spark generator which produces five impulses per second, enabling the trolley acceleration to be accurately determined.

The weights which produce the accelerating force are hung directly onto the paper strip.

All required equipment is supplied. Further rolls of electro-sensitive paper are available.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results

  Fletcher's Trolley

Features

• Traditional design
• Self-contained
• Bench mounted
• Total mass of moving system can be maintained constant for different
  acceleration masses
• Five trolley masses
• Acceleration determination by ink trace
• Confirmation of Newton's Second Law
  of Motion
• Determination of Gravitational Acceleration
• Three year warranty

Range of Experiments

1. To show that a force causes a mass to accelerate, and that the acceleration is proportional to the force
2. To compare experimental and theoretical values of forces required to accelerate a given mass
3. To determine the acceleration due to gravity, g

Description

This type of equipment has been used for many years to introduce students to accelerated linear motion, in particular the dependence of the acceleration on the net force causing the motion. Confirmation of Newton's second law of motion and the determination of gravitational acceleration are possible.

This strongly built traditional apparatus produces very accurate results. The trolley has five removable weights. During an experiment, the total mass of the moving equipment can be maintained constant by transferring weights from the rear of the trolley to the load hanger.

Acceleration is measured using an inked brush attached to a vibrating arm. This traces out an oscillatory trace on a piece of paper fixed to the trolley.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Rolling Disc on Inclined Plane

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Measurement of moment of inertia by
  rolling and oscillation
• Three year warranty

Range of Experiments

To determine and compare the moment of inertia of a disc by three methods:-

1. Motion down a plane
   
2. Oscillating pendulum
   
3. Calculation

Description

The moment of inertia of a rolling object is the rotary analagy of mass and governs the rotary acceleration. It can be determined in three ways; by rolling, oscillation or calculation. All should ideally give the same result but the student can be introduced to differences caused by different experimental techniques

A pair of machined rails form an inclined track for a disc rolling on a spindle through its centre. The inclination of the track can be readily altered by raising an end fitted with a height bar. Two discs are supplied; the larger has a diameter of 150mm and a thickness of 22.5mm, whilst the smaller is 100mm by 20mm. This enables two moments of inertia to be used.

The moments of inertia of the discs are determined from the time taken for the disc to roll down the slope. They may also be found from a subsidiary experiment using an oscillating pendulum in which the disc spindles are supported on knife edge bearings and a pendulum is attached to the shaft. The moments of inertia are estimated from the periodic time of the assembly.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Reaction of Beams Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Direct measurement of reactions by
  spring balances
• Loads and supports can be placed in
  any position
• Practical verification of equilibrium of
  vertical force or moments
• Simply supported beams or levers can
  be set up
• Three year warranty

Range of Experiments

1. Experimental determination of the reaction forces in the supports of a simply supported beam under various loadings
2. Measurement of loads and moments on a lever
3. Comparison with calculated results and validation of the principle of equilibrium

Description

A horizontal length of material with a vertical load system is called a beam. It is one of the most basic engineering ways of supporting a load. External forces such as the applied loads and the beam support reactions have to be in equilibrium. Given a loading system, the support reactions can be calculated from force and moment equations.

This apparatus is designed for simple experiments and demonstrations on simply supported beams. Two spring balances act as supports and enable reactions to be read directly. Three movable load hangers allow loads to be put in a number of positions.

Levers can be investigated by suspending the beam from the free standing frame, and holding down the end with a spring balance.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Forces on a Beam Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Direct measurement of reactions by
  scales
• Loads and supports can be placed in
  any position
• Practical verification of equilibrium of
  vertical force or moments
• Simply supported beams or levers
• Three year warranty

Range of Experiments

1. Experimental determination of the reaction forces in the supports of a simply supported beam under various loadings
2. Measurement of loads and moments on a lever
3. Comparison with calculated results and validation of the principle of equilibrium

Description

A horizontal length of material with a vertical load system is called a beam. It is one of the most basic engineering ways of supporting a load. External forces such as the applied loads and the beam support reactions have to be in equilibrium. Given a loading system, the support reactions can be calculated from force and moment equations.

This apparatus is designed for simple experiments and demonstrations on simply supported beams. Two scales act as supports and enable reactions to be read directly. Two movable load hangers allow loads to be put in a number of positions.

Levers can be investigated by placing the beam across one of the scales. Different leverage ratios can be set up using an adjustable tie rod which locates in one of three alternative positions on the base plate. The force in the rod is measured by a linear spring balance.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.

  Triangle of Forces Apparatus

Features

• Low cost, effective teaching
• Self-contained
• Bench mounted
• Direct measurement of forces
• Adjustable lines of action of forces
• Practical verification of triangle of forces
• Three year warranty

Range of Experiments

1. To find any suitable combination of three coplanar forces in equilibrium
2. To compare the results with the graphical solution obtained by drawing the triangle of forces
3. To demonstrate that th resultant of two known forces is equal and opposite to the equilibrant found experimentally

Description

A bench mounted circular table with a central pin and 360º protractor has three pulleys on adjustable clamps round the edge. Conditions of equilibrium are obtained by centralising a small cord ring over the central pin with cords to load hangers where the loads and lines of action are variable.

The triangle of forces in equilibrium can be constructed and the resultant of two known forces can be found.

This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.