quote:

Originally posted by Sam Pickens:
As I understand you attempted to balance before?
Check bearings for proper installation ensuring bearing fixed and float is proper and alignment - bearing to shaft and bearing to bearing. Belt driven? Loosen belts; if it won't turn freely, assume binding.

Yes; unbalance occurs at 1X running speed but doing a bump test is also adviseable to ensure you're greater than 20% away (hopefully), else you'll have to elect to alter or balance what you have - history should determine.

Certainly imblance can be corrected using the axial position but confirmination of all planes must confirm. Setup your once per rev trigger and acquire data if a simple one-plane job. Maybe your job is a two-plane balance job! If so, are you using software? Yes, does it have an 'over-hung' program? If not treat the near end reading as the 'far end' and same with near end.

If this is a critical job and equipment, it may not be a good place for OJT except by looking over the shoulder of a consultant for a learning curve.

You must weight out all factors. Limited info here can get you off in a wrong direction. Maybe you can provide more info.

quote:

Originally posted by David_G:
With overhung rotors in many cases vibration is the highest in axial direction, so why not tackle it first. At the same time watching or using multiple measurement points for optimisation as suggested above will be very helpful.

quote:

Originally posted by Ralph Stewart:
I have had tremendous success in using the axial direction for balancing. Even used some unorthodox or seemingly "you are joking" positions.

"Don't knock it unless you have tried it."

quote:

Originally posted by William_C._Foiles:
You sound like you are trying to use one sensor measurement for one balance weight. Many of today's balance programs will let you optimize among several measurement planes, e.g. least squares programs, which may work with your data collector or other balance instruments.

Using more than one measurement can show if a single plane will balance all the measurements satisfactorily, much more easily than otherwise.