The THEORY of MACHINES range enables clear and comprehensive learning of and topics. An understanding of the way in which forces act and react, is fundamental when studying the application of loads on a variety of fixed structures and rotating machinery. The THEORY of MACHINES form a comprehensive range of equipment, equally suitable for demonstration and experimental work.

All the THEORY of MACHINES hardware operates in a standalone mode, with a large number being supplied with Data Acquisition Software.

## HTM1 Wheel and Axle

Wall mounted apparatus for investigating the mechanics of a simple wheel and axle machine. Students are able to obtain equations for the relationship between load and effort, and hence obtain a value for the limiting efficiency of the machine. Velocity ratios can be calculated along with understanding the effect on effort, friction and efficiency with increased load.

## HTM2 Wheel and Differential Axle

Through the use of a wheel and stepped differential axle, students can determine the velocity ratio and comparison with calculated values for simple wheel and differential axle machine.

## HTM3 Worm and Wheel (30 : 1 ratio)

Wall mounted apparatus for analysis of the efficiency, velocity ratio and mechanical advantage of an industry standard worm and wheel pair

## HTM7 Gear Tooth Form

The gear form apparatus is designed to show and describe how gear teeth are defined and how basic gears work. It also explains the form of an involute curve and how this is used to create a gear tooth profile.

## HTM8 Cam and Follower Apparatus

This compact bench mounted self contained apparatus enables the observation of the rise and fall of various cams and followers supplied.

## HTM9 Simple Flywheel

Wall mounted apparatus to allow students to verify the second law of motion applied to a flywheel i.e. the relationship between torque and angular acceleration. Students can compare experimental and calculated moments of inertia of a disc as well as study the energy transformations.

## HTM11 Spur Gear Lifting Machine

The floor or bench mounted apparatus assists in determining the mechanical advantage, velocity ratio, efficiency and limiting efficiency of a single or double gear train.

## HTM17 Crank and Connecting Rod

Apparatus to show the relationship between crank shaft rotation and piston displacement for a fixed "cylinder". The stroke of the connecting rod and hence piston can be adjusted by securing its end to the different fixing points on the radius of the crankshaft.

## HTM18 Oscillating Cylinder

Apparatus to determine the relationship between crank angle and piston stroke, the effect of changing crank radius and evaluates the relationship between angular and linear speeds and accelerations.

## HTM19 Hooke's Coupling

Apparatus that allows the investigation into the relative angular displacements of shafts at opposite ends of a Hooke's coupling and observes the effect of changing the angles between the axes of the coupling and the interconnecting rod.

## HTM20 Ackermann Steering

This apparatus consists of a complete model Ackerman linkage mounted on a flat board. It is ideal for demonstration or experimental work and is an aid to understanding the design principles involved within a steering system.

## HTM21 Castor, Camber, King Pin Inclination

This apparatus represents a scale model of the wishbone and king pin arrangement of a front wheel suspension complete with a wheel on an adjustable stub axle. The king pin assembly includes a steering link to demonstrate how a real car works.

## HTM22 Relationship between Angular and Linear Speeds

A stepped shaft with three diameters is carried in a bracket which then allows the comparison of the angular rotation of a shaft and the tangential speed at the circumference.

## HTM23 Gear Train Demonstrator

Bench top unit to clearly demonstrate the functionality of gear trains, pulleys and belts. Based around a bench top unit, students can quickly assemble single and compound gear trains, pulley and belt arrangements. Theory and analysis behind the key elements of the apparatus function is supplied.

## HTM24 Universal Drive Module

This compact bench top unit is constructed around a motor that is used for driving a variety of customer apparatus. The apparatus allows speed, torque and power to be monitored and calculated.

## HTM25 Gear Train Apparatus

Understanding the basics of gear trains is important. This apparatus ensures this is done in a simple, visual and durable way. Small, compact and self contained bench top unit for introducing students to gear trains and epicyclic gears.

## HTM26 Winch Apparatus

This industrial winch allows students to determine the efficiency, velocity ratio, characteristics of the winch under increased load and the safety elements of the winch.

## HTM28 Crank Mechanism

Compact model and visual apparatus of a crank mechanism, with crank shaft, con rod and piston. This wall mounted apparatus is used by students to observe and record the crank motion and forces involved with a simple engine mechanism.

## HTM34 Gearbox Apparatus

This apparatus represents a sliding mesh gearbox, with clear visible gears to aid the students understanding of the principles involved.

## HTM38 Disc Brake Apparatus

To carry out experiments to investigate the relationship between the normal force acting on the brake pads, the effective radius of the brake pads and the braking torque.

## HTM66 Static and Dynamic Balancing vibration

A self-contained bench top unit for the analysis of static and dynamic balancing of masses on shafts. Students learn about static and dynamic balancing, force polygons, couple polygons and vectors.

## HTM67 Whirling of Shafts

To be a bench top, self contained apparatus for the demonstration of whirling speeds of flexible shafts of different lengths and diameters.

## HTM72 Cam Analysis

Bench top apparatus to demonstrate the dynamic investigation of cam and follower mechanisms, as used in motors for actuation of the valves. The cam mechanism consists of 4 interchangeable cams and 2 different cam followers. A mass and spring are used to simulate the valve. To demonstrate "valve bounce", the spring rate, lifted mass, spring compression and speed are all adjustable. A set of springs and added masses are supplied. Each cam is easily interchanged. A Data Acquisition Interface with software is supplied to allow the rise and fall of the cam to be monitored. Valve bounce can be easily observed using the interface and software. All rotating parts are contained within a transparent safety guard.

## HTM73 Gear Assembly Unit Combined Drives

Based around a rigid, sturdy frame a variety of drive arrangements can easily be interchanged and fixed into position. Bearing blocks ensure excellent, repeatable alignment of the drives along with smooth running. The drive arrangements include dual belt drive, chain drive with tensioner, spur gear train, dual spur gear, compound bevel gear and spur gear, compound worm / wheel gear and bevel gear, rack and pinion with a spur gear drive. A cranked handle operates the drives giving more control and feel for each drive arrangement. The layout of the drives gives an excellent visual indication of motion, direction, velocity, and mechanical action.