Trimming a controline plane

Hi OhBee,

Check your handle positioning:
Some people hold a handle like a pistol. That is, the top of the handle gets trimmed to have it closer to the model than the bottom. Basically, the bottom is already "back," so increasing/moving "down" doesn't make a whole lot of movement. It takes effort to hold the handle square to the plane (both lines/lead-outs the same length from centerline). This one got me. Once I recognized it and trimmed it out, I had smoother flights.

Check your lead-outs:
At each lead-out, measure each line from fully pulled one way to wing tip, and pull the other and again measure to wing tip. You want to measure the amount of movement, and then check to see if the midpoint in stroke places the elevator in neutral. Check both lines.

Check your control throw:
Hopefully the model is well sorted out such that an equal pull up causes a reflection of "x" degrees up, and pulling the same down from neutral causes the same deflection of "x"degrees down.

Recognize any inconsistencies, and check for possible adjustments. The hope is that the bellcrank is in neutral, and that both lead-outs are the same length from bellcrank ends. This may not necessarily be the same for a tapered wingtip. But it should be the same from the centerline of the model. Some times the elevator pushrod can be bent to "shorten up" the rod and reposition the relative angle between the bellcrank/model centerline and the elevator.

Also review http://flyinglines.org/mckay.trimming.html

There are.other trimming documents on flyinglines.org.

I hope that makes sense...if not, we can diagram it.

Side note: The Wido Satan was built with no bellcrank limiter stops, so this model will have more travel one way than the other (I seem to remember up having more "up")...but checking the controls with similar line movements (not max travel...say 3/8" from centered) should show similar movement. On that plane, one next rib to the bellcrank platform is the limiter. But I seem to remember cutting a clearance hole in that rib to allow for more up travel.