---------------------------------------------------------- Rocket-List Digest Archive --- Total Messages Posted Fri 10/24/03: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:47 AM - -4 tail mods?? (Parkhurst Maj Christopher J) 2. 07:28 PM - Re: -4 tail mods?? (u2nelson) ________________________________ Message 1 _____________________________________ Time: 11:47:27 AM PST US From: Parkhurst Maj Christopher J Subject: Rocket-List: -4 tail mods?? --> Rocket-List message posted by: Parkhurst Maj Christopher J Well, I'm back from shooting at the indians and the USMC was kind enough to send me up to Reno to be a TOPGUN Instructor....bummmer! All moved into my new hanger at Stead field and pushing ahead full steam (again) on building my F-1(#20). Almost have enough parts to put together an airplane. Question: I have completed an RV-4 tail to John's plans (still have to move bottom rib of VS..ooops) but am interested in beefing up the HS spar. Anyone done this? Seems to me that the Fwd spar is a little thin and could do with a douber in the middle and/or a couple of angles at the inboard ribs. I know there are some smart guys out there with ideas, just remember to make them "Marine-proof". Thanks in advance. Semper Fi Chris "Screech" Parkhurst Maj USMC -4 tail mods?? Well, I'm back from shooting at the indians and the USMC was kind enough to send me up to Reno to be a TOPGUN Instructor....bummmer! All moved into my new hanger at Stead field and pushing ahead full steam (again) on building my F-1(#20). Almost have enough parts to put together an airplane. Question: I have completed an RV-4 tail to John's plans (still have to move bottom rib of VS..ooops) but am interested in beefing up the HS spar. Anyone done this? Seems to me that the Fwd spar is a little thin and could do with a douber in the middle and/or a couple of angles at the inboard ribs. I know there are some smart guys out there with ideas, just remember to make them Marine-proof. Thanks in advance. Semper Fi Chris Screech Parkhurst Maj USMC ________________________________ Message 2 _____________________________________ Time: 07:28:19 PM PST US From: "u2nelson" Subject: RE: Rocket-List: -4 tail mods?? --> Rocket-List message posted by: "u2nelson" The RV-4 horizontal is indeed in need of some beefing up. The forward spar is week at the top in compression, a loading situation that is not normally encountered, but with enough speed and some negative G, like in turbulence, it is possible. The failure mode is buckling. To fix this add a standard extruded angle to the top of the spar, spanning the forward spar from rib to rib. Once the spar is inside the ribs, and under the skin there is no problem with buckling. You can pick up the rivet pattern of the planned rivets. The only other area I beefed up was the forward spar of the vertical, doubling it with a piece of .032 and extending up a couple inches into the skin area, this was primarily for extra sheer resistance against the attach bolts. Greg Nelson N144X -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com]On Behalf Of Parkhurst Maj Christopher J Subject: Rocket-List: -4 tail mods?? --> Rocket-List message posted by: Parkhurst Maj Christopher J Well, I'm back from shooting at the indians and the USMC was kind enough to send me up to Reno to be a TOPGUN Instructor....bummmer! All moved into my new hanger at Stead field and pushing ahead full steam (again) on building my F-1(#20). Almost have enough parts to put together an airplane. Question: I have completed an RV-4 tail to John's plans (still have to move bottom rib of VS..ooops) but am interested in beefing up the HS spar. Anyone done this? Seems to me that the Fwd spar is a little thin and could do with a douber in the middle and/or a couple of angles at the inboard ribs. I know there are some smart guys out there with ideas, just remember to make them "Marine-proof". Thanks in advance. Semper Fi Chris "Screech" Parkhurst Maj USMC -4 tail mods?? Well, I'm back from shooting at the indians and the USMC was kind enough to send me up to Reno to be a TOPGUN Instructor....bummmer! All moved into my new hanger at Stead field and pushing ahead full steam (again) on building my F-1(#20). Almost have enough parts to put together an airplane. Question: I have completed an RV-4 tail to John's plans (still have to move bottom rib of VS..ooops) but am interested in beefing up the HS spar. Anyone done this? Seems to me that the Fwd spar is a little thin and could do with a douber in the middle and/or a couple of angles at the inboard ribs. I know there are some smart guys out there with ideas, just remember to make them Marine-proof. Thanks in advance. Semper Fi Chris Screech Parkhurst Maj USMC