May - Rcsoaring.com

Aileron control was very slow this day.Turbulence was high and quickresponse was needed. Rudder couplingwas ineffective probably due tothe low dihedral, RVC and TPA.Next day the wind was a lot moreforgiving. Launches again were verygood with excellent zoom at the top. Itwas now noted that the ship had apronounced bank to the right. Thiswas corrected by either aileron trim ora lot of left rudder. Thermal turns wereflat and efficient without ruddercoupling; too much rudder couplingcaused the inboard wing to spiral intothe turn. Aileron throw and differentialwere increased to handle bothadverse yaw and a higher roll rate.Wing servo installation has problems. Iwanted to use the servo cans suppliedbut there were a couple of issues. Theholes are precut in the wing so there’snot much you can do about them.However, they were all cut about 3/8"too close to the trailing edge whichallowed the TE side of the can to stickout of the hole by ~ 1/16" while the LEside of the can was about 1/32" belowthe lip of the hole, I glued a 1/8" pieceof balsa to the back side of each canand then hit it with a belt sander. Youhave to sand the taper through thebottom of the plastic can at the TE endbut after a little work it came out OK.Each well was glued in with Goop andallowed to sit overnight.The next problem with the winglinkage was the hinge line on the flaps.Both the aileron and the flap use amolded in hinge (part of the skin). Itlooks like it’s glass or release cloth; it’sdefinitely not Kevlar. But both hingesare cut on the TOP of the wing. There’sno way to get a 90 degree flap deflectionwith this set up. Even 30 degreesis a stretch. There was even a nice gapseal structure for the flaps, but it’s allwasted with this hinge location.I cut off the flaps, filled the gaps withbalsa and then sanded and taperedMay 2003until it worked right. However, boththe location of the servo cans and theflap hinges are avoidable problems ifthe manufacturer/supplier used a littleforesight.After sorting out the flaps and servomounting, the wiring harness andconnectors supplied with the kitworked out very nicely. I used FutabaS133 servos for the ailerons and 351’sfor the flaps (metal gears).A problem also cropped up with thelinkage supplied with the kit. Theaileron and flap horns are brass screwswhich allow fine adjustment of theconnection height. However, theyrequire a large, angled hole in thecontrol surface which is awkward.Also, the slop in the threads leads to alot of play in the control. I glued thethreads (CA) to eliminate the excessplay after properly adjusting the servoend points. Bill Masserang (SLNT)suggested getting some metric nutsand jamming them down to take outthat slop.Off to the field for flying.First day out was very windy and cold.Launches on my mini-winch were truebut erratic due to the wind gusts.Release from the hook was fine. Thezoom was outstanding. Even fromshort launches the plane carriedenergy very well.A close look at the setup at homeindicated that the left V-tail incidencewas about 1 degree off from the rightthus explaining the tendency to bankto the right. Additionally, the right V-tail had a warp going in the samedirection. The warp was ironed outwhile the indexing was fixed byrelocating the mounting wire in thestab and then gobbing up the oversizehole with epoxy. These fixes cured thebanking problem.Another day of flying in calm weatherseemed to have things about right. Asport winch or hi-start launch is finewith the tow hook as installed. However,like most 2M ships, this one doesnot really excel at launch by pulling alot of tension and running it fast. Theywork better with a fair amount ofcamber and a pull that tends to kitethem up the line. Use the final third ofthe launch for speed and you’ll getseveral hundred feet more altitude onthe zoom.Now, for the rest of the story.I tried hard to stick to this design asshipped. As you might infer from thewrite-up to this point, there were somefrustrations. I wanted to address thoseat the time but played it by the book tosee how it would come out. After asession or two with a full power winchon a windy day I finally threw in thetowel and decided to fix the problems.First of all, the 120 V-angle just doesn’twork for me. On a hard winch launchit’s really squirrely. Yaw stability ispoor and the forward towhook makesfor some entertaining high speedPage 17