Hi T-Nagers, I know that this is a largely Mechanical question, but I need your recommendations for light-weight materials that I could use in place of aluminium to make a vibration test jig. I have been landed with designing an ESS jig to take a 14.5kg (32.5lbs) box that will be attached in three places - by a wedge-shaped tongue into a groove arrangement along the rear bottom edge, and by two ARINC fasters at the bottom of the front panel below all the interface connectors. The ESS Vibration test is 10 minutes Random vibration in one axis. Frequencies range between 20Hz and 2000Hz, with the vibration profile ramping up between 20Hz and 80 Hz at 3dB/octave to an acceleration spectral density of 0.04g^2/Hz, then ramping down again between 350Hz and 2000Hz at -3dB/octave. The vibration table we have will take a maximum theoretical weight of 82 lbs at a spectral density of 0.04g^2/Hz before it self-aborts, so allowing for some oscillation around the max s.d. figure of the profile and a margin of safety for the weight of the Unit to be tested, I reckon I have a maximum weight allowance for the vibration test jig of 37.5 lbs. The jig we have, designed by someone else without a lot of science or math involved, weighs in at around 26kg (58lbs), so it has to lose a lot of weight before we can use our own vibration table. If I can't put the jig on an effective diet, I'm faced with relying on renting expensive time at an outside facility that's already pretty popular, so my windows of opportunity are unlikely to match the times when I need to use the vibrator without a lot of dead waiting time. Hope someone out here knows what I'm talking about and can help. I've never known this forum to be be completely stumped for an answer to anything yet. Peter [This e-mail is confidential and may also be privileged. If you are not the intended recipient, please delete it and notify us immediately; you should not copy or use it for any purpose, nor disclose its contents to any other person. Thank you.] --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------