Q-108: I gather that a regular RC servo is suppose to be mounted to
hardwood or plywood trays (or beams) using the normally supplied rubber
grommets, brass bushings, and wood screws. I’ve noted on many of the smaller RC
model aircraft that the recommendation is to simply use “mounting tape." Is that
a safe alternative for mounting servos? What kind of specific tape should I use?
Are there any tricks I should know about using this tape?
A-108: This is a good valid question that most authors tend to ignore
because they feel it is “obvious.” Well, not everything is!
The tape method of mounting servos is fine for the smaller model aircraft and
for slow-flying aircraft. If you expect to do aggressive maneuvers with your
aircraft, you had better get those servos securely mounted with the prescribed
wood screws.
The tape I always use is the Scotch Brand (3M) heavy-duty, double-sided, foam
tape. I usually keep a roll each of No. 110 (1/2-inch wide) and No. 114 (1-inch
wide) on hand. I’ve had servos installed with this tape stay in place for
several years without any adhesion problems. It won’t last forever, but it works
well. Another advantage is that the foam material tends to isolate some of the
aircraft vibration that might normally be transmitted to the servo.
One important step in the use of this mounting tape is to have a clean surface
before applying the tape. The surface will usually be balsa or plywood on the
interior of your fuselage (or wing in the case of aileron servos). Before
applying the tape, you must seal the wood. The best way to do this is to apply
thick cyanoacrylate followed by accelerator to quickly cure it.
After that I cut a strip of the mounting tape, peel off one side of the
protective paper and apply it to the servo case. Then I remove the other
protective paper wrap and position the servo for mounting. When you have it
aligned up just press the servo to the fuselage side or any part of the aircraft
that you selected. Press as hard as you can and hold that position for a few
seconds. The servo should be adhered to your aircraft for a long time to come.