taut wire alignment limits 1

[Tmoose]

A large experimental machine is being built. Finished Bearing bores are over 24 inch diameter and about 108 inch C-C.
We need to confirm bore-to-bore alignment and also position a 120 inch inside diameter stator relative to the bearing bores. Laser kits for stuff this big is a little rare.

What kind of tolerances are practical and reasonable using a "taut wire method ?

Thanks,

Dan Timberlake

 

[unclesyd]

We could come within 0.001 without any problem. As checked by a boring bar it was generally a little better. Since I've have lost track of our expert I'll have to defer on what could be achieved with the experienced millwrights.

Here is a company that did have a very knowledgeable person on staff that could answer your question. They also carry all the equipment need for taut line measuring.

http://www.powerhousetool.com/align.htm

 

[EnglishMuffin]

Don't see why you couldn't do it with a regular bore alignment laser - it's not really the laser that's the problem - it's the tooling you would have to make to mount the laser and targets on - probably big disks with holes in them.

 

[blfarrar]

Hi

Depends really on the attitude of the wire, I worked extensively on taught wire measurements in machine tools - but we always ahed the object to be measured in sucha position that the wire was vertical - supending a weight, the weight being in a bucket of lube oil.

We used a converted micrometer with a sinple bell & buzzer (low voltage) the micromter mounte in a simple fixture that allowed the alignment to be referenced to the wire (the micrometer had a pointed contact end where the ratchet used to be)

We obviously couldnt exceed the accuracy of the micrometer - but we could discriminate 0.001 over distances of 30ft plus (gauging perpendicularity).

If you want to email & sketch the shape of the housing I might be able to suggest a method
Best of luck !

Bruce L Farrar.
Works Engineering Manager
Marshalls Mono PLC.Brookfoot Works.
Halifax W.Yorks UK

 

[DAVIDSTECKER]

"Power Transmission Design" magizine in its Oct, 1992 edition had an article and chart to determine the "Sag" in a horizontal tight wire you might find helpful.