Page 35 - QR CIMAR LASER SCREED

When you’re satisfied that the engine and the hydraulic oil are sufficiently warmed up, level the machine
with the Head Lift switch, verify that the laser electronics are working, and finally, check the speed of the
vibrator.

Last, but not least, ta moment to protect your screed from drying concrete. Spray the screed head, the
stabilizers and wheels - anything that will come into contact with wet concrete - with a form oil or other
concrete release agent.

At this point, if everything has checked out OK, you can move on to setting up the laser transmitter.

LASER TRANSMITTER SETUP

There are many types of laser transmitters in use by the construction industry. The type that you will
want for your screed depends on the type of work that you do. If you do all flatwork, then a non-angling
transmitter from Trimble will work fine. If you plan on doing slope work, then you should be using a
transmitter that is capable of single or dual slope, whichever your job demands. Those can be precisely
tilted so that the plane of reference light remains parallel to a grade of up to 10% uphill or downhill and
along one or two axis. Other transmitters will vary between maximum slope the transmitter can achieve
will become more important.

Also, every transmitter has some method for leveling the base unit. Check the instruction manual for
your specific transmitter to determine the applicable procedures.

Finally, some laser transmitters have multiple louvered windows which can be closed to prevent the
laser beam from shining on areas of potential reflection. This is helpful when setting up the transmitter
because you can open only those windows that are necessary to allow light to pass over the placement
area. If your transmitter does not have this capability then you should take precautions to make sure
that part of the beam does not shine away from the placement area where it could strike a pane of glass
or other shiny surface. Reflected beams that bounce back toward the place ment area can cause
interference and confuse the screed control system.

If you’ve chosen a spot for your transmitter that is next to a suitable column, you can mount the
transmitter with a column clamp. If not, you’ll have to use a tripod. When using a tripod, it’s important to
make sure that the legs don’t slip during screeding operations. The best way to insure that the legs will
remain stable is to position the feet of the tripod in existing saw cuts or other indentations. Once the feet
are placed, press them down firmly with your foot. Also check to make sure that all the nuts and bolts on
your tripod are tight and that the safety chains are attached. Finally, remember that the safety chains
should hang loosely between the legs so that they won’t transfer vibrations from leg to leg.

As was mentioned earlier, the screed determines the height of the screed head by constantly checking
the reference signal from a laser transmitter. In operation, the transmitter is mounted near the front of
the placement and at a height of about seven (7) feet above the benchmark height. Keeping the
transmitter at least this high above the floor makes it less likely that the laser will be blocked by people
or other moving obstructions.

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