Larry, Jeff is pretty close to what the DAR said. The RC servo does needs power to hold position. The DAR stated that if it lost power it would not remain fixed in place and therefore would potentially cause flutter in the elevator - therefore unsafe. Right now I only have a ground adjustable trim tab on the elevator. When I fly two people, I definitely have to hold forward pressure on the stick.
Since I've already got the servo, I'm looking at trying to figure out how to use the RC servo to control a trim spring inside the cockpit on the control stick instead. Shouldn't be any problem there if I lose power. Rob Schmitt Message: 24 List-Post: krnet@list.krnet.org Date: Sat, 20 Jan 2007 17:29:03 -0700 From: jscott.pi...@juno.com Subject: Re: KR> RC servo To: kr...@mylist.net Message-ID: <20070120.172903.420.0.jscott.pi...@juno.com> Content-Type: text/plain; charset=us-ascii On Sat, 20 Jan 2007 18:46:39 -0500 (Eastern Standard Time) "Dan Heath" <da...@alltel.net> writes: > That's funny. I am using a mirror motor out of a Mercury Sable. And > it > works great. For how long, I can't guess, but if it craps out, I > will put > in a Ray Allen. For now, this $5 servo is working just fine. > > See N64KR at http://KRBuilder.org - Then click on the pics > See you at the 2007 - KR Gathering > There is a time for building and a time for FLYING and the time for > Flying > has begun. > Daniel R. Heath - Lexington, SC > -------Original Message------- > > The RC Servo trim system was said to be unsafe by the DAR > so in its spot is the ELT remote panel. The Ray Allen Trim Servo unit use a gear drive from a small electric motor that locks where it's at when the voltage is removed. I suspect that Dan's Sable mirror motor is very similar. A RC servo has to have voltage to hold a position. The heavier the load against it, the more amps it needs to pull and the more likely it is to fail. If I found an RC servo in the trim on a Tech Counselor inspection, I would advise the builder to remove it. If I found it on a condition inspection, it would have to be removed before it gets a signature in the logs. The DAR was right on the money with his recommendation. Jeff Scott A&P
