FORCE REDUCTION WITH A VISCOUS FLUID TIMER
Viscous fluid timers go by many names. Silly Putty, Badge, Button, etc. All provide a relatively lightweight way to DT a small plane. Such timers are quite sensitive to the ambient air temperature and one must make adjustments during a day of flying as temperatures change. These timers are also very susceptible to changes in timing due to pull on the line. For very small planes like gliders, such pull is quite low, and the timer works fine. When use is attempted on larger planes such as gas models, the force needed to hold the stabilizer down is fairly high, and such line tension can not be allowed on the timer. There are various ways to deal with this. The below method has been used successfully by many people and there are numerous variations of it. This sort of technique could be well used with the Texas Timers Micro I pinchoff.
Thanks to Tandy Walker for sending this to me.
When the timer rotates as a result of the tension line, the red
string is released at the desired time, allowing
the long wire to lift up and the line to the stab is released, and DT happens.
You may want to use some
thread and epoxy to secure the aluminum tube to the plate. A small spring made
from tiny music wire such
such .008/ .010 dia. would provide a more dependable and consistent force. The
guide shown is used to
retain the spilt ring for the next flight and is for convenience only.