MM 320 UNIVERSAL VIBRATION APPARATUS
GENERAL DESCRIPTION

This apparatus is used for studying a wide range of vibration experiments namely, pendulums, mass-spring, free and forced vibration, lateral vibration, torsional vibration, vibration with and without damping.

The apparatus consists of a basic unit for use with optional accessories for individual experiment.

TYPICAL EXPERIMENTS

Part Name. Description
MM 320-010 Simple Pendulums.

This is for determination of period vs pendulum length.

Two spheres made of steel and wood are suspended on cords from pins on a pendulum cross beam with knife edge support.

 

 

Part Name. Description
MM 320-011 Compound Pendulum.

This is for determination of the center of gravity of the rod.

A round steel rod with an adjustable knife edge is suspended on a pendulum cross beam with knife
edge support.

 

 

Part Name. Description
MM 320-012 Reversible Pendulum (Kater Pendulum)

This is for determination of the acceleration due to gravity.

It consists of a rod with two adjustable knife edges and a sliding cylindrical bob. It is to be
suspended on a pendulum cross beam with knife edge support.

 

 

Part Name. Description
MM 320-013 Bifilar Suspension.

This is for determination of the moment of inertia of an irregular shape object.

A uniform bar is suspended by cords to the pendulum cross beam with knife edge support.
The bar is drilled at regular intervals along its length to carry two pegged masses. The radius of
gyration or moment of inertia of the bar assembly can be determined from the periodic time of
torsional vibration.

 

 

Part Name. Description
MM 320-014 Center of Percussion.

This is for determination of center of percussion.

It consist of two pendulums supported by a pendulum cross beam with
knife edge support. One pendulum is a light steel rod with a steel ball and an adjustable knife
edge. The other pendulum is a wooden compound pendulum with an adjustable steel weight and
a knife edge. The length of the simple pendulum is adjusted so that when allowed to swing and
impact the compound pendulum, there is no lateral movement of the knife edge on the flat
support. The impact line on the compound pendulum is the line of center of percussion.

 

 

Part Name. Description
MM 320-020 Mass-spring Apparatus.

This is to demonstrate relation between vibration frequency, spring constant and mass.

A coil spring is suspended from a spring bracket attached to the top frame. Different masses are
placed on a platform suspended from the lower end of the spring. Three different springs are provided.

The platform rod is guided in a bushing to achieve a vertically free motion.

The apparatus is equipped with a gauge to measure spring position.

 

 

Part Name. Description
MM 320-030 Free Vibration Apparatus.

This is for determination of the natural frequency and amplitude of vibration with and without damping.

The apparatus consists of a beam hinged on a trunnion attached to the left vertical frame. The other end of the beam is attached on to a spring which is hung from a spring bracket. Near the end of the beam is a recording drum which hold a recording paper. A pen attached to the end of the beam provides a vibration trace on the recording paper. To ensure safety, a guide frame is provided to contain the beam vibration. Extra mass or a damper may be put on to the beam.

 

Part Name. Description
MM 320-031 Forced Vibration Apparatus.

This is for a study of frequency ratio vs amplitude and phase angle.

The apparatus is the same as used in MM320-030 Free Vibration with an exciter motor attached to the beam. The exciter motor speed is variable and is shown on an indicator. Two unbalanced rotors are attached to the exciter motor. A synchronous belt connects the exciter motor to the unbalanced rotors thus providing a forced vibration when the motor runs. Weights can be attached to the rotors.

A damper is attached to the beam and a disc recorder with pen and holder is used for
phase angle measurement.

 

 

Part Name. Description
MM 320-040 Lateral Vibration Apparatus.

This is for a study of the frequency ratio vs amplitude and phase angle.

The apparatus consists of a beam hinged on a trunnion attached to the left vertical frame. The right end of the beam is attached to two bearings which are free to move in a guide attached to the right vertical frame. An exciter motor is attached to the middle of the beam. Two unbalanced rotors are attached to the exciter motor. A weight with its holder is attached to the unbalanced rotors. By running the exciter motor at different speeds, the beam natural frequency can be excited.

Further experiments can be carried out by attaching a damper onto the beam. An electrical contactor is attached to the beam and a micrometer is attached to the bottom frame beneath the contactor. By adjusting the micrometer to be in contact with the electrical contactor, the amplitude of the vibration can be determined and at the same time the stroboscope is triggered such that the phase angle between the beam vibration and the exciter motor rotation can be determined.

 

 

Part Name. Description
MM 320-050 Undamped Vibration Absorber.

This is to demonstrate vibration absorption by a double contilever system.

The vibration absorber consists of two masses clamped onto two spring steel cantilevers
attached to the exciter unit. The system frequency can be tuned by adjusting the masses along
the spring cantilevers. The system can be used to absorb and reduce the unbalanced force.

 

 

Part Name. Description
MM 320-060 Torsional Vibration Apparatus, single rotor system.

This is to determine the moment of inertia of a fly wheel and period of rotation.

A shaft is attached to a fixed chuck attached on the bottom frame. A compound
rotor with a chuck is attached to an axle which in turn is attached to a vertical
frame. The other end of the shaft is clamped to the rotor chuck which is free to
rotate. Three different diameter steel shafts are supplied.

Optional accessories: This includes damping discs and oil pot with support. It
is to be used with MM 320-150B Computer Interface 2 for torsional vibration
(optional).

 

 

Part Name. Description
MM 320-061 Torsional Vibration Apparatus, two rotors system.

This is to determine vibration period and the node on the shaft for two rotors.

A single rotor and a compound rotor with axles are attached on the left and right vertical
frames. The rotors are free to rotate on the axles which are set at the same height. Each rotor
has a chuck which can be clamped onto the same shaft. Three different diameter steel shafts are
supplied.

 

 

Part Name. Description
MM 320-062 Torsional Vibration Apparatus, single rotor with damping.

This is to measure damping coefficient and investigate the effect of oil depth.

For a damped torsional vibration, a vertical set up on one side of the frame is
required. A fixed chuck is attached to the top frame. The shaft passes through a removable nylon
guide bush and is gripped by a rotor chuck at the lower end. Attached to this rotor bottom is a cone for immersion into an oil reservoir beneath for damping. The oil reservoir level can be adjusted to vary the immersion, hence damping. An angular scale is attached to the rotor and angular displacement is indicated by a pointer. Amplitude-time graph of vibration is obtained from a drum recorder on the rotor and a sliding pen. Three different diameter steel shafts are supplied.

OPTIONAL EQUIPMENT

BASIC UNITS (OPTIONAL)

 

Part Name. Description
MM 320-001 Floor Standing Basic Unit

This is a floor standing 30 x 60 mm aluminium profile twin frame on wheels with adjustable footings and a cabinet for housing optional accessories.

The unit can be used for all vibration experiments.

Window opening : 900 x 650 mm
Net (unpacked) shipping dimensions W x L x H : 88 x 107 x 171 cm
Net weight : 68 kg.

 

 

Part Name. Description
MM 320-005 Bench Top Basic Unit

This is a bench top 30 x 60 mm aluminium profile twin frame with adjustable footings. The unit can be used for all vibration experiments except MM320-062.

Window opening : 900 x 650 mm
Net (unpacked) shipping dimensions W x L x H : 36 x 107 x 91 cm
Net weight : 22 kg.

 

 

Part Name. Description
MM 320-007 Pendulum Basic Unit

This is a bench top aluminium profile single column of 30 x 60 mm
aluminium profile with adjustable footings and top attachment for pendulum experiments.

Net (unpacked) shipping dimensions W x L x H : 31 x 56 x 15 cm
Net weight : 4 kg.

 

ACCESSORIES (OPTIONAL)

Each experiment requires several accessories to be used with the basic unit or the basic frame. Only one experiment at a time can be carried out. If several experiments are required duplicated accessories need not be supplied. Details of accessories are available on request.

 

OTHER OPTIONAL ITEMS

Part No. Part Name
MM 320S

Learning software for the Universal Vibration Apparatus.

This software provides a simulation for actual experiments on the apparatus. It is an inexpensive means to learn about the subject for those who do not yet have the real equipment and it is also very useful for class introduction before proceeding to run the actual apparatus.

MM 320-150A Computer Interface 1 – Beam Vibration.
This includes distance sensor computer interface unit and software for beam vibration and mass – spring experiments .
MM 320-150B

Computer Interface 2 – Torsional Vibration.

This includes rotary encoder computer interface unit and software for torsional vibration experiment.

MM 320-150C

Computer Interface 3 – Pendulum.

This includes proximity sensor computer interface unit and software for pendulum experiments.

Other optional equipment please contact manufacturer ([email protected])