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Air Knife/Squeegee Accessories
Optical Dimensions has designed an Air Knife and Squeegee accessory for cleaning surfaces that are
subjected to coolants, lubricants, etc. in the process. For accurate measurements, Lasercheck requires a
clean surface. The Air Knife and Squeegee designs have been tested to determine they adequately clean
surfaces in the process to allow accurate Lasercheck measurements.
The above figure shows a view of Lasercheck from the end and side illustrating air knife positioning for
surfaces approaching Lasercheck from the “long” side of the box. The end view at the upper half of the
page shows how the air knife should be positioned close to the surface (maximum 1/8” away). It should
also be pointing straight at the surface (along a radial to a cylindrical center). This positioning has provided
the best performance. Once that is set, start the surface moving, apply water to the roll (do not traverse the
surface or Lasercheck) and turn on the air. You will see a dry stripe being created by the air knife. Slide
the air knife in its mount until the laser spot on the surface is centered in the dry stripe. This provides
optimal positioning of the air knife for operation. A correct automatic or manual approach to the surface
will position both the Lasercheck head and the air knife optimally now. The only consideration that would
call for resetting of the air knife would be in the event of dramatically different diameter cylinders that
could cause the air knife to be positioned too far or too close to the roll surface due to the dramatically
different curvature of the surface.
There are two reasons for use of a squeegee in conjunction with the air knife. First, obviously, it reduces
the amount of coolant that the air knife has to remove. Second, it will help keep the Lasercheck windows
clean. The windows get dirty because the blowing of the air knife on a very wet roll causes coolant to
splash on the Lasercheck. If the Lasercheck head gets wet, the coolant drips down and deposits on the
windows. By removing the rough amount of coolant from the surface, this splash is virtually eliminated.
