When measuring the flatness of a slewing ring bearing for a crane, the D22 (or D23) laser transmitter is used. The transmitter is secured to the flange with its magnets. The detector unit is placed at the marked points all around the flange, and the measurement values are recorded at each point. Three zero (reference) points with 120° pitch are calculated by the system. The results can be displayed as a 3D graph or in figures. You can move the zero points to find values that entail the least tooling work.
Flatness = straightness in two dimensions
Flatness measurement is carried out, for example, on machine tables, wire ends in papermaking machines, flanges and slewing bearings (circular planes), machine bases etc.
Measurement of flatness/twist on rectangular planes
First, the beam is roughly aligned along and across the measurement object. The detector is then positioned on the selected measuring points and the values registered. According to the measurement, three of the measuring points are set to zero, and the other points are recalculated for the newly created reference line. The measurement values at the other measurement points will show the deviation from the laser plane. The measurement values can be recalculated so that any three of them become zero references, with the limitation that a maximum of two of them are in line horizontally, vertically or diagonally in the co-ordinate system. (If there are three in line, it is just a line, and not a plane!)
Measurement of flatness/twist on circular planes
The measurement of flatness/twist on circular planes such as flanges is also based on the use of three reference points, situated at intervals of 120° around the circle. Decide the number of measurement points and which three will be the reference points on which the laser plane will rest. All measurement results displayed are now relative to the three selected reference points/laser plane. It is possible to measure both inner and outer circles on the flange (ID/OD), with up to 300 measuring points. You can then display the graph in the EasyLink (Version 2.2) program, and also work further with the measurement values to test different settings; best fit to centre, best fit around zero, best fit all positive/all negative, best fit absolute values etc.
Flatness measurement with a reference plane parallel to the horizontal plane
The laser beam is adjusted according to the vials on the laser transmitter, and the measurement value at the first measurement point is set to zero. The measurement values at the other measurement points will show the deviation from the horizontal plane.
Which points on the surface are to be measured?
When measuring flatness, it is important to decide which points on the surface are to be measured. These are marked in a co-ordinate system in the X and Y axes, or at each bolt hole, for example on a flange. Up to 300 measurement points can be handled by the Easy-Laser® system.