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Message ID: 165     Entry time: Tue Jul 16 16:22:28 2019
Author: Andy R. 
Type: Progress 
Category: BS BRDs 
Subject: BRD5 

BRD5 tuning with new v5 blade. Has a much larger k and requires much more mass. The stack of masses might be too high to add on the beamsplitter (see picture attached). We had to look for longer screws.

  Bounce Mode Mass Frequency (Hz)   Roll Mode Mass Frequency (Hz)
Trial 1 2.74g+2*0.91g+screw=5.167g f=36.063   2.74g+screw+washer=3.399g f=54.288
Trial 2 4.23g+2*1.1g+screw=7.094g f=25.568   2.54g+2*1.1g+screw+washer=5.420g f=34.64
Trial 3 4.23g+2.7g+2*0.62g+long screw=8.976g f=19.248   4.23g+2*1.1g+long screw=7.295g f=24.80
Trial 4 4.23g+2.7g+1.64g+long screw=9.361g f=18.320      
Trial 5 4.23g+2.7g+2.27g+flathead screw=10.071g f=16.368      

 

Attachment 1: BRD_tuned_with_v5_blades.jpg  751 kB  Uploaded Wed Jul 24 11:30:03 2019  | Hide | Hide all
BRD_tuned_with_v5_blades.jpg
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