Hi Craig I have a part share in a Sonex to which we have fitted the spring trim system as part of converting the aircraft to the Sport Trainer configuration.
The trim system, as designed and fitted to the Sonex, is very effective with a single pilot on board but can tend to run out of nose up trim when operating the aircraft at close to maximum all up weight. This typically isn't a major issue though as it can easily be overcome with just a little back pressure on the stick until some fuel burns off at which time the trim becomes effective enough to keep the nose attitude correct. I would like to emphasize that this only occurs when flying the aircraft is at maximum all up weight. Perhaps the only criticism I have with the design is the actuating wheel. You need to turn the wheel through about seven or eight full revolutions to go from full rear to full forward trim when checking it as part of your normal pre-start checks. It isn't an issue in flight however as the amount of movement required when flying is usually only one or two revolutions to trim the aircraft out however it is a bit of a pain during pre-flight checks. Note that we have considered fitting the trim wheel with a small crank handle which would probably make for easier operation but we have not done this on our Sonex setup as yet. I have published some photo's of the fitting of the trim system and the Aerocarb throttle quadrant to our Sonex on my website at the following link (http://www.kiwikr.co.nz/090_03_newthrottle.html) and also some followup work which was required after the install inspection was carried out. ( http://www.kiwikr.co.nz/090_04_inspectionwork.html). I can recommend the Sonex spring trim system as fitted to the Sonex and I will likely be fitting the same system to my KR as it should simplify the construction of the Horizontal Stab with there being no need to cut out and fit the standard trim tab. Regards Gavin Magill Auckland NZ On 10 December 2011 06:44, Craig Williams <[email protected]> wrote: Craig wrote.............. > http://www.sonexaircraft.com/orders/trimfaq.html > > Has anyone used the Sonex trim system in their KR? I have convinced > myself that the this is a good system and want to try it. > > Craig > www.kr2seafury.com > _______________________________________ >
