Fixturlaser Geometry

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Stern Tubes & Bore Alignment

Accurate measurement of stern-tube and gearbox driver alignment, is essential, to avoid edge loading and, or, shaft whirling.


The crankshaft, propulsion shaft and the propeller must be on a common centre line, to avoid the propeller from wobbling about its running position. Even a few millimetres of wobble can result in the development of high stresses in the shafting arrangement, leading to structural failure. Damage to a propulsion shaft can also lead to more serious issues on a vessel.


Using Fixturlaser NXA Ultimate, stern tube alignment is easy, accurate and a straight forward process. Additionally, the Fixturlaser NXA can carry out gearbox to motor shaft alignment including cardan or offset shaft alignment.

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Straightness Measurement

The straightness application is measured in two axis. The laser beam is used as the reference. Deviation, in distance, between the laser beam and the measurement object is measured in two or more positions with the use of a receiver.The program allows for up to 99 points to be measured. Typical straightness applications are measurements of machine guides, machine beds, machine ways and guide rails.

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Bore Straightness Measurement using Clock Method

Straightness with the clock method is used to determine the center position of full bores, horizontally or vertically. The laser beam is set roughly to the center line and each bore center is measured by rotating the receiver 180 degrees in each bore. Typical applications are bore measurements of bearing journals in diesel engines, compressors or gear boxes.

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Bore Straightness Measurement using Arc Angle Method

Straightness with the Arc Angle method is used to determine the center position of full or half bores, with a horizontal center line. The laser beam is set roughly to the center line and each bore center is measured by rotating the receiver from three up to nine positions in each bore. Typical applications are straightness measurements in bearing journals for example, compressors, turbines or machinery with split casings.

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Circular Flatness Measurement

The circular flatness measurement application uses a laser plane as the reference. The deviation in distance between the laser plane and the measurement object is measured in one or more positions with the use of the receiver. The program allows for the measurement of up to three circles with 99 points in each one. Typical applications include the measurement of flanges and round machine foundations.

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Rectangular Flatness

This application uses a laser plane as reference. The deviation in distance between the laser plane and the measurement object is measured in one or more positions with the use of the receiver. The program allows for up to 150 points (10 x 15) to be measured. Typical applications include machine beds and machine foundations. For the latter application, it is particularly beneficial to combine flatness measurement with shaft alignment when installing rotating machinery. First one checks the foundation’s surface for possible irregularities, essentially a pre-alignment check. Once installed the machine is then checked for possible shaft misalignment with a Fixturlaser NXA system.

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