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Maverick now offers injection molding preventative maintenance packages to the plastics industry! Repair, troubleshooting, and installation of injection mold machines and peripheral equipment.
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Horizontal Roll Parallelism |
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 How we measure horizontal roll parallelism using laser alignment equipment
First, the laser is placed on an instrument stand near the reference roll at the side of the machine and leveled using its 1 or 2-arc-second level vials. The vertical laser plane is made approximately parallel to the reference roll using visual aids.
Determining Horizontal and Vertical Reference PointsWe then place one target horizontally on the reference roll at the closest point to laser and adjust it until it detects the laser and zeros in. The target is then moved to the far end of the roll. A second target is placed on the same point on the roll that is closest to the laser and zeroed out. Since both targets were zeroed at the same point on the roll, they become the reference points for the roll.
 The vertical laser plane is "bucked in" or adjusted until the same reading appears on the 2 reference targets. The laser plane is now parallel to the reference roll.
Determining Offset Reference CenterlineSince the laser is placed outside the machine and the second vertical laser plane is perpendicular to the first, the second laser plane, in effect, becomes the offset centerline of the mill. This offset centerline has a range of 100 feet (30.5 meters) on either side of the laser. To measure other rolls for parallelism, the offset centerline must be temporarily established by placing 2 reference targets, horizontally, either on floor fixtures or on the side frame of the mill. The reference targets are zeroed, thus becoming the offset reference line and are not touched during the remainder of the alignment.
Aligning the RollsTo check the parallelism of an individual roll, the laser and stand are moved along the offset centerline until the desired roll or section of rolls is reached. The laser should be positioned to allow about 4-5" of horizontal space between the laser plane and the roll to be measured. The instrument is then leveled.
 The yaw adjustment on the laser base is used to make the second vertical laser plane parallel to the offset centerline, using the temporary reference targets as guides. When the same reading appears on both reference targets, the laser is parallel to the centerline.
Finally, a target is placed horizontally on the roll closest to the laser and zeroed. The target is then moved to the far end of the roll and the deviation from parallel is measured. Since the readings are live, the roll can then be adjusted until both near and far target positions read zero, which would mean the roll is aligned and parallel to the reference roll.
Since the laser generates a plane, rolls at any elevation in that section that are within 2 feet (610 mm) horizontally of the laser plane can be measured for parallelism without changing the setup of the laser. |
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Last Updated ( Tuesday, 27 September 2005 )
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