Laser shaft alignment equipment, Touch probes, Laser tool setting, Laser machine alignment systems, Roll alignment
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Correcting Soft Foot

The importance of correcting soft foot errors demands effecitve laser soft foot measurement

Direct Angle Measurement
Why Stealth Technology is Better over Long Distances

Exceptionally Rugged 8" and 10" Laser Display Screens

Check out the torture tests that Stealth Laser display units were subjected to in development.

Stealth Laser Shaft Alignment Website
Hamar Laser Instruments have launched a new website dedicated to their industry leading STEALTH range of Laser Alignment Systems

FibroDRIVE+ in Australia
New FibroDRIVE+ tables with integrated control & drive allow simple implementation of programmable rotary positioning.

Fibro Rotary Motion
ISTecnik appointed national distributor of Fibro rotary motion systems

Efficient Sole Plate Levelling
Dual axis electronic levels from Digipas shorten sole plate levelling times by 50%.

New Ultra Precision Digital Machinists Level
The 2-axis DWL8500xy is suitable for precision machine levelling to 1 arcsecond in both directions.

TC-76D All New Digital Scanning Probe

The all new TC76D scanning probe from Blum provides large time savings and interesting new probing possibilities.

New Versions of S-680 Laser Shaft Aligner
New S-680BP and S-680BT laser shaft aligners from Hamar put the ultimate alignment precision in reach of more users.

New S-660 Laser System - Affordable Performance
The outstanding Hamar S-660 wireless laser shaft aligner now released in Australia.

New Precision Dual Axis Levels
A new range of 2-axis precision digital electronic machinists levels provides high levelling accuracy and simplicity.

Laser Pump Alignment
Hamar S-670 sets new standards in pump alignment efficiency and ease of use.

CNC Machine Calibration
Fast and affordable CNC machine axis calibration with LICS-100A

Used Laser Shaft Aligner Sale
One used S-680 Laser Shaft Aligner on sale now

Laser Precision Machine Levelling
The Hamar L740 series scanning laser levels provide ideal levelling solution for all machine tools.

Lasers Vastly Improve Pulley Alignments
Reflected beam laser technology provides far superior pulley and belt alignments in rapid time.

Precision Machine Tool Alignment

Hamar Multi-plane Geometrical Lasers Ideal for Aligning Large Precision Machine Tools

Soft Foot in Shaft Alignment
It is impossible to properly align a machine with a soft foot, but as many types of Soft Foot condition exist it is important to understand the possible causes.

ISTecnik Precision Laser Metrology
Soft Foot in Shaft Alignment

It is impossible to properly align a machine with a soft foot, but as many types of Soft Foot condition exist it is important to understand the possible causes.

A sophisticated laser shaft alignment system such as the Hamar S-660, S-670 or S-680 is able to reliably gauge the amount  and effect of soft foot problems in a machine before shaft alignment is attempted. Based on the most common cause of a soft foot condition being that the mounting feet are not coplanar, the system determines which foot needs to be shimmed and calculates shim thickness to eliminate the soft foot problem.

In simple terms this process is like packing up one leg of a 4 legged table to eliminate its wobble.

However, a soft foot result may also be caused by several other common errors in the machine, such as a bent foot condition. In this case, one or more of the machine feet may not be sitting parallel to the floor in addition to not being coplanar to the other feet.

If there is a significant bent foot problem, the soft foot condition detected by the laser shaft aligner will not be fully corrected by shimming the recommended foot. When this happens it is necessary to take a closer look at the condition of the machine feet. The result of  a bent mounting foot is that it is straightened elastically as the mounting bolt is tightened down, generating forces on the other feet and potentially inducing soft foot reading in the other machine feet when checked with the laser. When a bent foot is shimmed normally, the measured soft foot will not disappear.

The task to identify a bent mounting foot is to look at the parallelism on the gap under each single foot, which is often most effectively done with a feeler gauge check under each corner of the individual foot.

If a bent foot problem exists there are two possible solutions. The ideal solution is to re-machine the feet or the mounting base to be parallel across all mounting areas.

Another solution in the field is to build up stepped shims across the face of the non-parallel foot. This may be done by first shimming the gap to the lowest corner of the foot, then inserting a set of 4 to 6 shim steps progressively up to the highest corner of the foot. Each shim is cut down to support a smaller and smaller foot area, like a staircase.

Other possible causes of soft foot in machine shaft alignment include so called "Squishy Foot", where debris, grease or burrs prevent solid initial contact between the base, shims and foot surfaces,  and "Induced Soft Foot" which is potentially caused by extraneous forces on the machine.

In addition to these types of  soft foot, it is possible that a gap under one of the mounting feet may occur because the foot design is excessively flimsy or possibly damaged, and the rigidity of the machine structure is sufficient to resist movement as the foot is tightened down. This problem is a common result of poor mounting base design or poor construction techniques.

Base Design
It is essential that a machine base is designed to be sufficiently rigid to not bend under the machine weight or the pipe loads. Many bases are easily strong enough to support the operating loads but are not rigid enough to maintain a good alignment in field conditions, where a deflection of just a fraction of a millimetre may be sufficient to exceed soft foot tolerances.

Other common design errors include not making an allowance for the mounting pads to be machined flat after fabrication.

Construction problems include an allowed base machining operation not being done correctly with consideration of distortion due to internal welding stresses, that may require rough and finish machining operations separated by release and re-clamping of the frame after the roughing operation releases stress related distortion.

Similar errors may be also be induced when the machine frame is set down and grouted. For small frames, setting down the frame firmly on three points only prior to non-shrink grouting will often produce minimal distortion from its original state.

In summary, a high performance shaft laser alignment instrument is able to detect soft foot conditions and quantify the shimming correction required for a non coplanar foot. Soft foot correction should be done before every alignment, and will save hours of wasted alignment time and avoid machines being left in an unstable final aligned condition.

When a soft foot correction cycle does not produce good results, look carefully for other possible causes of the soft foot reading before simply adding to the shim stacks.

In the end, correctly resolving any measured soft foot problem is important in order to obtain good alignment results.

For more information go to the Laser Shaft Alignment page, call IS Tecnik on 02 9546 5676 or email us at:

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