I mounted Cirrus CS20BB servos in my Chrysalis and the control arms do not stay on tight enough without the screws. Is there a way to put in a screw without drilling through the side of the fuse? The servos are already mounted with servo tape and I built the narrow fuse version.

From : Don Stackhouse

Oops! Stacey, you have several options, none of them pretty.

You can drill a hole in the side big enough to install the screw. This really isn't that bad, since it will be easy in the future to get at the screw for adjustments (although this is rarely necessariy if the installation is set up correctly to begin with). Just try to avoid drilling through the spruce longerons.

You can fit a wood shim between the fuselage side and the top of the arm on the servo. Glue this to the fuselage side to trap the arm in place on the servo. I don't really recommend this option, its reliability is very poor.

The cleanest, easiest and best option is to peel the servo loose (a firm, steady pull should do it), clean off the remains of the old servo tape, install the missing screw, and put the servo back in position with some fresh servo tape. Let the pushrod and linkage help you locate the servo. Take two popsicle sticks or two pieces of leftover leading edge dowel and put them chordwise across the tail surface near the control horn, one on eiter side. Strap the ends of the sticks together with small rubber bands. This "splint" will hold the control surface, horn and pushrod in neutral while you put the servo in place.

Don Stackhouse @ DJ Aerotech