August 28, 2008
Balancing and phase analysis tip
Three birds - one stone
The job of capturing phase data for analysis or balancing has been made easier by the use of laser tachometers and similar instruments.
They can, or have replaced the standard strobe light method which required synchronizing the strobe firing rate to the shaft speed and then adjusting the firing angle to a specific reference point.
In a single operation, a laser tachometer emits a beam of light toward a piece of reflective tape on the shaft and determines rotational speed and reference angle by timing the pulses from the reflected beam.
One key element of this process is applying the reflective tape to the shaft. This simple task is the source of much aggravation in the real world.
Three common problems are:
1) It is difficult to make the reflective tape adhere to shafts that are oily, rusty, wet or dusty
2) finding the reflective tape with the laser and getting a good return signal from a new and very shiny shaft surface
3) separating the backer paper from the reflective tape - especially with cold fingers!
A few turns of black electrical tape applied around the shaft -sticky side out- will eliminate all three problems. It will keep the reflective tape firmly attached to the shaft (without having to peel off the backer paper) and serves as a mask so the reflective tape will be clearly visible - to the eye and the laser. Since the sticky side is out, the black tape can be easily removed with a single slice of a knife along the axis of the shaft.
Reader tip provided by Pete Castillo
Field Service Technician
Kirby Risk Mechanical Solutions and Service http://www.kirbyrisk.com/MSS.cfm
Thanks Pete - your Maintenance-Tips hat is on the way!
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