KRnetHeads, Joe Horton was asking me about my rudder the other day, and got me to thinking about rudder trim on KRs. When I first started flying, I had to keep a good bit of left rudder in, just about all the time except for landing, and a LOT in climbout. That added to the pilot workload more than you would think, and I found myself pushing on both the left (because of habit) AND the right both at the same time during landings, which is not good for the cables or the bellcrank. I really couldn't get a good feel for the rudder because of the huge bias I was having to apply just to keep the ball centered.
I finally broke down and added a trim tab after I saw the one on Bill Clapp's plane. Mine is pretty much just like his, about 6" tall and 1.25" wide. I started with a piece of 6" x 2.5" x .025" thick 6061-T6 aluminum, and folded it over about 30 degrees at the midpoint to make the thing shown at http://home.hiwaay.net/~langford/rudder_trim.jpg . I found that it still wasn't enough, so I bent it to about 45 degrees and now it's just about fine. It really will eliminate one more thing that occupies your mind while you're doing your first flights. Do yourself a favor if you're getting ready to fly and add one of these BEFORE you fly. You're going to need it anyway, so get it over with. As you can see from the photo, mine's just bolted on for the moment. Bill just sliced his trailing edge and floxed his in between the glass, but my trailing edge is all flox, so I couldn't do that. Mine really needs to be epoxied and feathered in place, and I guess I'll do that before it goes back to the airport. Ideally, you could cant the tail something like a degree during construction and gain the same thing, but when I build mine I was going to run a Type 4 off the "correct end", but I wasn't positive, so I left the rudder centered so I could "go either way". Troy Petteway does his trim with a cable and a spring connected to the rudder pedal. That works great with an 0-200, because it pulls on the left pedal so the control can be fastened to the fuselage wall, but for VWs and Corvairs it would have to be the right pedal, so it needs to be panel mounted. He drilled a hole in his panel with a little slot at the bottom of the hole, and uses one of those little "ball chains" like you see on old ceramic light fixtures. He has certain balls marked for climb and cruise, and pulls the chain out to the right color and drops it in the slot to set it. That works too, is adjustable for different flight regimes, and leaves no tab on the outside. Maybe I'll do that instead, come to think of it... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net --------------------------------------------------------------
