KR> Aileron Rigging - bellcranks and push pull cables
Just as aside, my Avid Mk4 has push pull control tubes for elevator and ailerons including a complex aileron "mixer" that allows the flaperons to operate as flaps and ailerons at the same time, and to fold the wings back without disconnecting anything. (Although at low speeds the system can deliver a "control reversal" condition. That only happens at low speed which usually also includes low altitude which is always a fun time to experience it.) I dont recall any friction issues.
KR> Aileron Rigging - bellcranks and push pull cables
Oh, and I forgot push-pull-cables. They can be bad news, and heavy is the least of it. The more curves there in the housings, the more slop you'll have as they take up the space between cable and housing, and the friction is much higher than a pulley system. There's a very good reason why the vast majority of aircraft use pull-pull cables, and it's less friction and virtually no slop. I have first hand experience on my "work project" for the last six years. A young engineer chose push-pull cables, and laying out on a table, they were "friction free". Install them, add a few curves, and it becomes a nightmare. And the higher load you put on them, the higher the friction goes. That doesn't really happen with pull-pull cables. We are changing back to what I recommended in the beginning...aircraft-type pull-pull cables. Granted, for straight, short cables, from stick to bellcrank, that'll probably work, and have the advantage of the ability to land if one side fails, but I don't know of a single KR (and very few other aircraft) that have had that problem. Give it a try though, and let us know how it works out. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Aileron Rigging - bellcranks and push pull cables
Tony King wrote: > But I'm pretty sure using push-pull cables with no > bellcranks would eliminate any differential action of the ailerons. > It might be possible to get some of that back by doing something like > what Mark Langford did with his ailerons (where the front edge sticks > up into the airflow as the aileron goes down) . I guess my question > really is what effect is that likely to have on a KR? Yep, you'll need a bellcrank if you want differential ailerons, and the plans version does that. Any kind of bellcranks works though...it's just the geometry of the hole pattern (which I'm sure you know). Frise ailerons work fine too. Either one does the job, but I chose to do a little of both, and it works great, as the only time I need to touch the rudder pedals is on takeoff and during windy landings or a slip. But Larry Flesner will be quick to tell you that the stock differential ailerons work fine too, just like they are, and that the best way to keep the ball centered in a KR is to simply keep your feet away from the pedals, whether straight ahead or in a turn...it works great! There's more on Frise ailerons buried in the page at http://www.n56ml.com/owings.html , but you might get lost in there. I don't recognize the young kid in those photos though... Mark Langford ML at N56ML.com http://www.n56ml.com
