other things to think about are what you use for control. if you use a pull pull system you may need to trim as the lines become stretched. If you seem to have to retrim all the time (besides small adjustments) check to make sure your controls don’t have a lot of slop in them or something has come lose or worn. Don’t use servo arms that have been drilled out for larger control rods and make sure all z bends are with 90% angles. Sometimes inexpensive servos will not center properly and will need to be constantly readjusted but should really be replaced