Pietenpol-List: Jury Struts and Spar Routings
Posted: Tue Aug 22, 2000 12:13 am
Original Posted By: Michael D Cuy
Subject: Pietenpol-List: Jury Struts and Spar RoutingsThanks for all the responses to the two questions I asked. I will continue to finish routing my spars.On the jury struts, I made a decision this afternoon to place the spare fitting for the jury at 49.5 inches from the butt of the spare. This I calculated in the following manner.Fundamental vibration of the wing section is 13 ft 2 1/2 in or 158.5 in.Divide by 2 and get the 1st harmonic, 79.25 in where lift strut fittings are placed. Further divide by 2 and get 2nd harmonic, 39.625 further divide by 2 for the 3d harmonic, 19.8125, further dividing by 2 to get the 4th harmonic 9.90 in. I added the 2d and 4th harmonics for a location of 49.5 inches. This is a node point where the natural vibration of the designated length of wood establishes its partials.I'm probably waaaaaay outside the ballpark on this theory but I think It will help minimize vibrations Corky in HOT La________________________________________________________________________________Date: Tue, 22 Aug 2000 10:36:53 -0400
Subject: Pietenpol-List: Jury Struts and Spar RoutingsThanks for all the responses to the two questions I asked. I will continue to finish routing my spars.On the jury struts, I made a decision this afternoon to place the spare fitting for the jury at 49.5 inches from the butt of the spare. This I calculated in the following manner.Fundamental vibration of the wing section is 13 ft 2 1/2 in or 158.5 in.Divide by 2 and get the 1st harmonic, 79.25 in where lift strut fittings are placed. Further divide by 2 and get 2nd harmonic, 39.625 further divide by 2 for the 3d harmonic, 19.8125, further dividing by 2 to get the 4th harmonic 9.90 in. I added the 2d and 4th harmonics for a location of 49.5 inches. This is a node point where the natural vibration of the designated length of wood establishes its partials.I'm probably waaaaaay outside the ballpark on this theory but I think It will help minimize vibrations Corky in HOT La________________________________________________________________________________Date: Tue, 22 Aug 2000 10:36:53 -0400