Gray Beard said:

"If the outer tube isn't glued in tight all along it's length about every 6 or 8 inches it will allow the rod to shift and it will change the trim "

Is that an in flight issue, because my trim changes are occurring on the ground prior to the flight when my Sig is sitting in the sun.

When I get my Sig home and inside the garage(out of the sun), the rudder and elevator go back to center.

Here is the paragraph from the Sig 4 Star 60 building manual:

Before flying, check and adjust all the pushrod linkages so that the control surfaces are in neutral position when the transmitter sticks and trim levers are centered. When you get to the field, don't be surprised if the elevator and rudder are slightly misaligned. Temperature and humidity changes can cause the nylon pushrod tubes to expand or contract slightly. Use the trim levers on the transmitter to return the control surfaces to neutral, and do the final trimming in the air.