MLS MMLS3 User manual

MMLS3 OPERATOR’S MANUAL
The aim of the MMLS3 Operators
Manual is to give information
regarding safe and efficient techniques
in operating the MMLS3.
The machine is a scaled down heavy
vehicle simulator used for accelerated
trafficking of model- or full scale
pavements.
MLS Test Systems
P t y L t d

MLS Test Systems Pty Ltd
Revised: April 2013 ii
MMLS3 operator’s manual
Contents
SECTION 1: UNPACKING AND INSPECTION..................................1
1.1 Packing list..............................................................................1
1.2 Unpacking...............................................................................2
1.3 Inspect the machine for damage during transport....................3
SECTION 2: FEATURES AND DESCRIPTION....................................4
SECTION 3: USING THE MACHINE....................................................8
3. Operation ......................................................................................8
3.1 Setting the wheel load .............................................................9
3.1.1 Measuring the wheel load ...................................................9
3.1.2 Adjusting the wheel load...................................................12
3.2 Setting up the machine on the pavement...............................13
3.2.1 Getting the machine into position .....................................13
3.2.2 Adjusting the height..........................................................15
3.3 Running the machine.............................................................19
SECTION 4: MAINTENANCE.............................................................21
4.1 The yellow (polyurethane) guide wheels...............................21
4.2 The drive belts.......................................................................23
4.3 The gap between the rails and the drum................................23
4.4 Aligning the drive drum ........................................................25
4.5 Changing a tire......................................................................27
4.6 Removing and replacing the springs......................................31
APPENDIX A: Using the Varispeed motor controller ......................32
APPENDIX B: The lateral displacement system...............................34
APPENDIX C: Maintenance checklist..............................................35
APPENDIX D: Circuit diagrams.......................................................40
APPENDIX E: Technical Specifications ..........................................45

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SECTION 1: UNPACKING AND INSPECTION
1.1 Packing list
You should have received the following items
1. The MMLS3 machine frame plus the following accessories:
a. One steerable “jockey wheel” and two fixed transport
castors wheels. (See Fig.1(h).
b. Two “skate boards” with base plates (See Fig.1(g))
c. Two link arms, about 350mm long, to link the machine
to the base plates (See fig. 4)
2. An “electric orange” control box
3. An electronic calibration unit to set the wheel load (See Fig.3).
This is packed in a wooden box, about 400x300x300mm.
4. One spare pneumatic wheel, complete with bearings and shaft.
5. Eight spare yellow guide wheels
6. The following metric tools
a. 10mm wrench
b. 13mm wrench
c. 16mm wrench
d. 17mm wrench
e. 14mm wrench
f. 5mm Allan key
g. 4mm Allan key
7. Suspension measuring gauge (See Fig.5)
8. A copy of this operator’s manual

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1.2 Unpacking
The machine comes strapped to a wooden pallet inside a
wooden crate and can be handled by either a forklift or a crane.
Once removed from the pallet the machine should not be
handled by a forklift, which will damage its underside. Off the
pallet the machine can be moved around on its own transport
wheels, or handled by crane. The crane should be attached to
the single shackle on top of the frame. The 300mm rubber
trafficking wheels cannot support the weight of the machine.
Care must be taken not to overload them.
The control unit, calibration unit, the two links for the lateral
displacement system, some other small parts and tools and the
manuals are packed in a separate smaller crate.
1.2.1 Open the large crate by undoing all the screws on the top and
remove the top plywood sheet. Also remove at least one of the
side panels. Remove the straps and, using a crane, lift the
machine from the pallet by the single shackle on top. Take care
not to bump the small bracket on the gearbox at the end of the
machine. Lower it to about 300mm from the floor, but do not
put the machine down.
1.1.2 Remove the jockey wheel from the pallet and mount it while the
machine is still hanging from the crane and then lower it to
stand on its wheels.
To mount the jockey wheel push the two 25mm holes
horizontally over the two studs at the end of the machine (see
Fig1), then slide it slightly upwards and engage the pin
The machine can now be wheeled around.
1.1.3 Remove the base plates and “skate boards” from the pallet.
These are used for the lateral displacement of the machine when
in operation. The “skate boards” are the two channel sections,
each with four wheels and two self-aligning bearings.

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1.3 Inspect the machine for damage during transport
Visually check for bent or broken parts. If anything looks
suspicious, please contact the supplier.

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SECTION 2: FEATURES AND DESCRIPTION
The MMLS is a scaled down heavy vehicle simulator used for
accelerated trafficking of model- or full scale pavements. The four
300mm diameter single wheels can typically apply 7200 real wheel loads
per hour. Normal inflation pressure for the pneumatic tyres is 700 kPa,
with a maximum of 800 kPa. The maximum wheel load is 2700 Newton.
The machine is supplied with the wheel load set to 2700 Newton. If the
machine is transported by air, the tyres are deflated to about 200 kPa.
Please inflate to the correct pressure before testing.
The machine contains the following main components: (See fig 1).
a) The rigid frame with four adjustable legs.
b) Looped guide rails mounted on the frame.
c) Four bogie carriages, each with one 300mm diameter pneumatic
wheel and six guide wheels.
d) Four link sections, each with six guide wheels.
e) The drive drum
f) The curved wheel guide
g) The mechanism for lateral displacement
h) Detachable castors for moving the machine over short distances.
i) The control unit in a separate box.
The bogies and link sections are linked together to form an endless chain
with a total of 48 guide wheels and four pneumatic trafficking wheels.
The guide wheels move along the two sets of guide rails. When a bogie
moves along the bottom straight section of the rails, the pneumatic tyre is
in contact with the underlying pavement, applying a load to it.
The spring loaded drive drum pinches some of the guide wheels against
the outer rail. As the drum rotates the guide wheels are moved along in
much the same way as with a planet gear system, driving the chain of
bogies around. The drum is driven by a 1.5 kW variable speed electric
motor.
The trafficking wheel of each bogie has an adjustable suspension system
by which the wheel load can be set. The suspension has a displacement
travel of about 20 mm. Once set, the geometry of the suspension system

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makes the wheel load practically independent (±5%) of displacement
within the 20mm range. When in operation, the suspension is kept
within its working range by adjusting the legs on the fixed frame. Care
should be taken not to overload the suspension by lowering the frame too
far.
The control unit is housed in a 400 x 500 x 200 “electric orange” IP65
(weather proof) metal box. It contains the following components:
1. The motor controller. See Appendix A for operating details.
2. Two counters to count the total number of wheel loads. One
counter is not resetable and its reading must be multiplied by
10, while the other one can be preset to stop the machine after a
set number of wheel loads.
3. The control system for the lateral displacement of the wheels on
the pavement.
To simulate lateral spread of wheel loads on the pavement, the
entire machine is displaced in the lateral direction by an electric
motor. The motor is controlled in such a way that more wheel
loads are applied near the centre of the track, giving a Normal
(Raleigh) distribution of loads over the width of the track. See
Appendix B for more details.
The 6 amp. trip switch (marked DC) on the right hand side of
the main switch serves as an electronic shear pin and will switch
the machine. The total width of the lateral spread of the wheels
on the pavement can be set by the knob next to the counter.
Power supply to the machine is 220 Volt 50/60 Hz AC at about 1.5 kW
(7 Amp).
Using the machine on wet pavements
The MMLS3 may be used on wet pavements. Most parts of the machine
(including the ball bearings in all the wheels) are made of stainless steel
or other corrosion resistant material. The electric connectors and
enclosures are of the IP65 (weather proof) type. It must be kept in mind,

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however, that under wet and dirty conditions faster than normal wear and
tear will occur which may shorten the life of the machine or some of its
components.

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SECTION 3: USING THE MACHINE
3. Operation
To operate the machine, follow the following steps:
Set the wheel load and tyre pressure as described under 3.1.
Move the machine into position by its transport wheels or by
crane as described under 3.2.1
Mount the base plates and “skate boards” for lateral movement
as described under 3.2.1.
Connect the three electric cables from the control box to the
machine as described under 3.3.2
Set the suspension operating level as described under 3.2.2
Set the lateral displacement as described in 3.3.6 below
Set the speed to a low value (say 10 Hz.) as described in
Appendix A below and press the green RUN button on the
outside of the orange cabinet and let the machine run for at least
one revolution to make sure that it is clear to run. Press the red
STOP button to stop the machine.
(To use the RUN and STOP buttons on the keypad, see section
3.3.8 below or Appendix A.
Record the reading on the right hand (mechanical) wheel
counter.
Set the electronic wheel counter to the desired number of axles
after which the machine has to stop.
Set the speed to the desired value as described in Appendix A
below (max. 48 Hz)
Press the green RUN button to run the machine.

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Press the red STOP button to stop the machine when necessary.
Before using the machine on wet pavements, read section 2 in
Supplementary Manual.
Every 500 000 wheel loads, apply grease to the side walls of the
guide wheels as described under 4.1
Read the maintenance checklist in Appendix C
3.1 Setting the wheel load
The load that is applied to the pavement by the trafficking
wheels can be set by adjusting the suspension springs on the
bogies. The suspension system is designed so that the wheel
load is practically independent of the vertical displacement of
the wheel. It is thus possible to set the wheel load beforehand
and, as long as it stays within the specified displacement range
during operation, rutting of the pavement or vertical displace-
ment of the machine frame will not affect it. This makes it
unnecessary to continuously monitor the wheel load during
operation.
3.1.1 Measuring the wheel load
Refer to fig. 3
The wheel load can be measured or set with the aid of the
calibration unit.
3.1.1.1 Take the calibration unit from its wooden box and unscrew the
50mm diameter flange and the two M10 nuts from the bottom
end of the unit. Mount the unit onto the channel beam on top of
the machine by means of the two M10 bolts. (It may be
convenient to completely remove one of the safety covers by

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removing its hinge pins.) Mount and hand tighten the flange.
Plug the unit into a 220 Volt AC supply.
3.1.1.2 Handling the chain of bogies by the round wheel shafts on the
link sections only, move one of the 300mm wheels to be exactly
underneath the flange of the calibration unit. Hold the bogie
firmly in place and turn the crank to push down onto the wheel.
3.1.1.3 Observe one of the two 25mm diameter rubber stoppers on the
wheel trailing arms (fig.3). As the wheel is pushed down, the
stopper will move away from the frame of the bogie. Turn the
crank until the gap is about 10mm and read the force from the
display. NEVER INCREASE THE GAP TO MORE THAN 20
mm, BECAUSE THE SPRINGS WILL BE OVER STRESSED.
Because of friction in the system a higher reading may be
observed while the wheel is pushed down than while letting it
move back. Turn the crank forwards and backwards about one
revolution at a time and note the average reading.
3.1.1.4 From time to time apply some MS grease to the threaded rod of
the calibration unit.
3.1.2 Adjusting the wheel load
3.1.2.1 Measure the wheel load as described in 3.1.1 above.
3.1.2.2 Refer to fig. 3 and apply a small amount of MS grease to the
thread on the spring shaft as well as one of the faces of a round
spacer (supplied) and insert it, small end first, over the open end
of the spring shaft, followed by a M16 nut (nut A). NEVER
USE A STAINLESS STEEL NUT, as it will seize onto the
shaft. If the wheel load is to be increased, tighten the nut to
compress the spring by about 5 mm, otherwise compress it by
about 2 mm. Release the locknut (nut B) on the flange at the
opposite side of the spring and move it away from the flange.
3.1.2.3 Adjust the position of flange B on the spring shaft by rotating
the spring and both flanges simultaneously. Make a mark on

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the flange and record the number of turns. To increase the
load, screw the flange away from the u-bracket (i.e. compressing
the spring). It should be possible to rotate the spring by hand if
nut A is, at the same time, rotated in the same direction by a
24mm ring wrench. One end of the spring assembly may be
lifted out of the spring support to get a better grip. Otherwise a
strap wrench may be used.
3.1.2.4 With the spring in position, release nut A, but do not remove it
yet.
3.1.2.5 Repeat the above operations for the other spring, using the same
number of turns.
3.1.2.6 Measure the wheel load as described in 3.1.1 above.
3.1.2.7 If the load is still not correct, use the measured load increment
and number of turns (see 3.1.2.3) to calculate the required
number of turns to arrive at the correct value and repeat the
above steps until the wheel load is correctly set. Also measure
the length of both springs. They should not differ by more than
2 mm.
3.1.2.8 REMOVE THE NUTS AND SPACERS ON BOTH SPRINGS.
3.1.2.9 Adjust the tyre pressure if necessary.
3.2 Setting up the machine on the pavement
To prevent damage to the machine, it is important that the pavement be
fairly flat and firm enough to carry the weight of the machine. Keep in
mind that the wheels travel at high speed and that bumps or holes in the
pavement may cause large shock loads.
3.2.1 Getting the machine into position
3.2.1.1 Move the machine in position on the test pavement by its
transport wheels or by crane.

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The jockey wheel with the beam is mounted by pushing the two
25mm holes horizontally over the two studs at the end of the
machine, then moving it slightly upwards and engaging the pin.
The two fixed wheels are mounted, one on each side of the
machine, by engaging the four 10mm pins vertically upwards
into the holes in the L-beams and then engaging the horizontal
pin to keep it from dropping out again. Install the R-clips into
the pins to keep them in place.
3.2.1.2 Refer to fig. 4 and slide the two base plates and “skate boards”,
one set at each end, in underneath the machine from the sides
and attach the links between the base plates and the lever arms.
Insert the R-clips to retain the links.
3.2.1.3 Lower the legs by turning the crank handles on top so that they
engage with the four bearings on the two skateboards. Under
operating conditions it may be necessary to fix the base plates to
the pavement to prevent them from moving around. The best
way is to drill 8mm holes about 50mm deep into the pavement
through the two holes in the base plate and to insert a 8mm steel
rod into each hole. Take care to fix the base plates in such a
way that the wheels of the skate boards will not jam on them,
i.e. they must stay 100% perpendicular to the centre line of the
machine.
3.2.1.4 Raise the machine high enough on its legs to remove the three
transport wheels. Adjust the two legs at one end of the machine
simultaneously by an equal amount and observe the bubble in
the spirit level mounted on top of the frame. This will avoid
twisting the frame by allowing it to stand on two diagonal legs
only.
3.2.2 Adjusting the height
The load of the wheels on the pavement is determined by the
spring settings and is practically independent of displacement.

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Refer to fig. 5 below. It shows a side view of the bogie
suspension system. In the machine the system can only be seen
from the top.
The large spring at the bottom pushes the rubber wheel
downwards to create the load of the wheel onto the pavement.
When the machine is lifted off the pavement the wheels moves
downwards so that the gap closes until the rubber stoppers make
contact with the metal frame of the bogie. The stoppers then
bear the force of the spring and the wheel cannot move further
downwards.
When the machine is lowered so that the wheel makes contact
with the pavement, the pavement starts to push the wheel
upwards and the stoppers move away from the metal frame.
The pavement now counteracts the force of the spring and the
set wheel load is applied to the pavement.
To be sure that the correct load is applied to the pavement the
stoppers should not make contact with the metal frame of the
bogie. To allow for unevenness of the pavement as the wheel
travels down the pavement test section, the initial gap should be
set large enough. The required initial gap is about 10mm. (See
Adjusting the wheel load under 3.1 above).
The 10mm suspension gap can be measured with the supplied
tool, as indicated in fig. 5. You can also feel the gap with your
finger.
To make the gap larger the machine has to be adjusted lower
onto the pavement by turning the handles on top in an anti-
clockwise direction. In the same way, to make the gap smaller,
the machine must be raised from the pavement by turning the
handles in a clockwise direction.

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3.2.2.1 Look through the large inspection opening in the side of the
machine and move any one bogie until the forward four of its
six yellow guide wheels are just out of the curve coming down
on the opposite side of the drive drum, and onto the start of the
bottom straight rail section. The bogies may be moved using
the control unit, set to a low speed (6 - 10 Hz), or by hand. To
avoid injury when moving it by hand, only handle it by the
round axles of the link sections.
3.2.2.2 Evenly lower the machine frame until the two black rubber
stoppers at the end of the trailing arms that hold the rubber
wheel just start to move away from the metal plate underneath
it. (See fig 3)
3.2.2.3 DISCONNECT THE MOTOR CONTROL UNIT FROM THE
MAINS. Refer to fig. 5, p16 and find the PVC measuring tool,
shaped like a human leg and foot. The “toe” of the gauge is
8mm high, increasing to 10mm where it is attached to the “leg”.
Holding the gauge by the “leg”, measure the gap underneath the
rubber stopper. Only one of the two stoppers needs to be
checked. Lowering the machine will increase the gap and vice
versa. The setting is correct when the “foot” fits in the gap
with little or no clearance. A tolerance of one or two mm to
either side is allowable.
3.2.2.4 Move the bogie forward until the forward two of its six yellow
guide wheels are just at the end of the bottom straight rail
section. ALWAYS DISCONNECT THE MAINS SUPPLY
BEFORE WORKING INSIDE THE MACHINE. Check that
the gap is still about the same. If not, adjust the two feet at that
end of the frame to correct it, even if it means that the machine
is not standing horizontal in the length-wise direction. Recheck
the gap in the first position.
3.2.2.5 Lock the four legs to prevent further rotation.