Practical Alignment Tools and Techniques

Browsing, as one does, for information about a specific instrument … I happened across this interesting short paper, downloadable from TKT Engineering:

**LINK**

https://www.thinkerf.com/Downloads/AlignTools.pdf

It majors on the alignment of substantial woodworking machines, but much of it should be of wider interest.

MichaelG.

What we used at work for vertical surfaces or short distances was a Wyler electronic inclinometer. It gave its readings in millirads which for small angles can be considered to be mm/m. For rotating shafts we used Pruftechnik laser based Rotalign kits. For horizontal distances for getting machined surfaces in the same plane or at the correct vertical offset we used a self levelling dumpy level with vertical scales held on the surfaces with magnetic bases from Brunson Metrology. With the dumpy level and the scales we could get far better levelling than with a precision inclinometer as we could get the difference in height over a number of metres down to less than 0.1mm. It was easier to achieve the levelling tolerances with the dumpy level and vertical scales.

The alignment of rotating shafts connecting two machines had to take into account thermal growth of the equipment so was often set up with odd angles and offsets over significant gaps (which are very hard to measure with long support arbors and dial indicators fighting gravity). Once we started using the Rotalign laser equipment it became much easier as you could enter the type of alignment you wanted to do and the angles and offsets you were aiming for. You also entered the dimensions of the flanges, their distance apart and the distances to the supports to be shimmed. The equipment then told you how much to shim each support by and how much to move the supports horizontally to achieve your required settings. After a confirmation check of the alignment you could then print off a report sheet for the quality records.

Back in the 1980's we once had about six draughtsmen and design engineers on the shop floor trying to figure out what the sag due to gravity was in a long arbor and what the measurements were telling us as a result. They were trying to do it using many sheets of graph paper and spent a whole day on the issue. Happily I was not involved because at times it got a bit heated. It was this sort of waste of time that allowed my department to justify the cost of laser alignment equipment for initial manufacture, testing and on site assembly and sign off. Time is money, especially when working in the middle of nowhere and often in some far off country.

Martin C

Useful.

cheers