Adjusatble leadouts

A question to all you master builders out there. When making your adjustable leadout how sensitive do you make them? Since I have never seen 1 I assume (I know thats bad but) it's a slidable piece of material thats attached to the last(?) wing rib by bolts or other method? Here is my first try at this. It's on a 1/2a profile. 1/8" ply 2 1/4" long,3/8" high. 2 4-40 bolts spaced 1/4" apart for adjustability? does this sound about right? Please let me know. Thank you, Steve.

Steve that sounds good. Putting a slide on a 1/2A is a fun way to experince how a adjustable guide can change your plane flight character.Just remember that your slide should be set up so that the CG is in middle of the slide. This is a good starting point. Wait untill you try it on a 35 sized plane. WOW it make a whole lot of diffenence. Line tenision, Yaw, Corner, Level flight, Overheads, all get better with proper trim. Scott

Sounds like you are on the right track. I glue up the frame for the slider out of 1/8 square spruce rather than trying to cut it out of plywood. For a 1/2A you could use 1/8 x 1/16. The slider itself is a small rectangle (3/8 x 1) of 1/8 ply with two long grommets through it for the leadouts and a blind nut for a 4/40. One 4-40 is plenty. I put the grommets close together and use unequal length leadouts to avoid line clip hangups. Set the slider for the first flight so that when you hang the airplane by the leadouts it points out a noticeable amount. When you fly the airplane look at the wing. Move the slider forward 1/16 - 1/8 at a time until you are looking right down the wing in level flight.

Whether you make the adjustable guide or buy one, use a little longer bolt than necessary, and then crunch the threads at the end after you insert it. This way if it should come loose, the bolt won't fall out and the assembly will reman together. It is good to check the tightness periodically. How do I know this? You don't have to ask. (Experience).

The lightbulb begins to flicker, I know now that an adjustable leadout is getting added to my Ringmaster. This brings up some more questions. Is there a recomended solid leadout diamater for for engine size or wing area?

Engine size, yes. If you are using solids, for anything from .020-.040 I would not recommend anything less than .031. Anything above that and .037 are probably better. The real key here is not in the pull (tensile) strength of the wire, but the fact that the wire will flex ever so much where it wraps around the belcrank. Any wire that flexes will eventually break. It is, thus, better to add a couple of extra grams of weight to make the controls solid and "bullet proof" than to risk the plane and anyone around it to a control failure caused by an inadequate size of wire.

Some cables are heavier and stronger than others. If properly bushed--by this I mean a "U" shaped piece of tubing that snakes through the belcrank and bends back upon itself so that the ends touch and there is no flexing of the cable, then .027 cables might be considered adequate in size for this same size plane.

When in doubt, I would rather go one size too big, for any crash is one crash to many--especially when it is caused by a control failure that could have been prevented.