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DAE ever get a weird vibration after swapping out a 5-year-old sheave?
I replaced a worn traction sheave in a 10-story building last Thursday and now there's a high-frequency hum above the 7th floor that wasn't there before, so has anyone else dealt with a harmonic issue after what seemed like a straightforward swap?
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xenarobinson21d ago
@jaken23 that's a good point but the resident on 7 complained first so that's where they started looking. I heard one of the guys at the supply house say sometimes a new sheave has a different mass distribution than the old one even if it's supposed to be the same part number. Could be the 7th floor is where the flex in the cable hits just right.
The groove profile change stone.jesse mentioned is real too, I saw a bulletin from one of the big elevator companies about it a few years back. They had to swap back to an older sheave design on a whole building because the new ones set off the whole cab frame vibrating.
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stone.jesse3mo ago
That high-frequency hum above the 7th floor is a classic sign of a harmonic. Check the sheave alignment and belt tension first. I've seen new sheaves with a slightly different groove profile set up a whole new vibration pattern.
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