String pot sag in g-field

Estimation of error due to sagging of 9" long string pot cable inb g-field.

Celesco, part MT2A-9E-9-10K-M2 BLK April 2007

The string pots oscillate a lot during strong shaking. BK thinks there must be some inertia of the spool in the string pot body. This was observed in high speed video of LJD01. The string pots seem to work just fine for static testing or before-and-after measurements of movement.

the attached calculations, with theoretical deflections due to spinning was done with a mathcad calculation and converted to pdf File:Mathcad - stringPotSag.pdf

mathcad file is at File:String pot sag.zip

the conclusion was that the error in length of the cable due to sagging of the cable was about 0.02% of the cable length

length of cantenary: 9" cable g level: 80 g

cable: 0.019" stainless steel coated in nylon cable tension: 9 ounces