User Manual
Foam rubber selection is also a topic for consideration. As foam density increases, its ability to dampen
vibration is reduced. The best choice for vibration isolation is foam rubber, not rubber foam. I know this sounds
a little weird but there is a difference. Rubber foam is what your stereo equipment and other stuff are packed in.
You can also get a mattress made of rubber foam. Although this will work to some extent, it is not the best
choice for vibration isolation. I buy foam rubber at the hobby shop in packages about a foot square. It is white
and has one slick side and one rough side. It is real rubber, not a man made poly-whatever material. Foam
rubber is definitely the better choice for vibration isolation.
Switches require the least amount of vibration isolation because they are usually potted inside the switch
cover. This means that they are filled with silicone or some kind of resin to capture the wire connections. High
frequency vibration will vibrate the wires at the connection point and cause a solder joint failure if the switch is
not potted. Remember this if you decide to build your own switch harness. NEVER use single conductor wire in
our hobby (except for landing gear and pushrods). Use only stranded wire. The more strands there are and the
more flexible it is, the better the wire is for us. Single conductor wire or wire with only 5 or 6 strands will not
hold up to the vibration. High frequency vibration is also the reason you should never use toggle switches for
radio switches. Toggle switches depend on spring pressure to maintain closure. Cheaper switches even when
they are new and good switches after they get older allow the vibration to cause the switch contacts to bounce
open and close effectively turning your radio on and off several hundred times a minute. This is hard on the
radio equipment. Toggle switches do not usually last long in our high frequency vibration environment. I know
there are heavy-duty toggle switches out there and you will get by for a while, but as the saying goes, "You may
win a battle or two, but you won't win the war." Do yourself (and your equipment) a favor; use switches that are
designed for our hobby.
There are many things in our hobby that seem to be working against our success. They are vibration,
dirt, gravity, fate, lack of funds, inexperience, etc., etc., just to name a few. The better understanding we have of
each, the more likely we are to succeed. The only way I know of to eliminate vibration to the radio gear is to
either not start the engine or start flying gliders. The more you do to reduce the vibration that gets to your radio
equipment, the longer it will last and the better it will perform.
I know there are soft mounts for the engine but I have no experience with them. Pilots I know who have
tried them have mixed reviews. Some say they are great, some say they rob power, some say they can't tell any
difference. I don't know. If anyone has experience with soft mounts, preferably more than one, it would make a
great article for later. That's it for now.
*** See you at the field ***