Oleg, Your AC assumptions are correct, but the powerful servo is really required when the plane is under high load, IE: on tow and during high G maneuvers. Under those conditions the loads on the stabs are immense and cause binding and friction in the stab pivot mechanism. Plus it's the only control surface on the plane that if it fails you're assured of crashing. (No redundancy) Go set a few pounds of weight on each side of the stab on your open class ship and see how well the elev servo pivots it. Norm PBSS
-----Original Message----- From: Oleg Golovidov [mailto:[EMAIL PROTECTED]] Sent: Tuesday, July 16, 2002 12:43 PM To: [EMAIL PROTECTED] Subject: [RCSE] Re: large servos on full flying stab >On a larger model like the ICON, guys have been using the JR DS 3421 >on the stab, another nice digital servo from JR. I was always puzzled a little by recommendations to use a mighty servo on the full flying stab. I totally understand the need for precision here (digital servos), but why use a very powerfull servo? If the stab pivots around its aerodynamic center and has a symmetric airfoil (both are true in 99.9% cases, including ICON I assume), then the control moments on the stab are near zero. The loads on the stab servo are miniscule compared to those of a flap servo. Am I wrong here? Oleg. RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
