📡 Trim
A small adjustment to a channel's center/neutral point — used to fix a car that pulls slightly or a plane that isn't quite level in cruise.
What it actually does
Trim shifts the neutral point of a channel in small steps, so a model that pulls to one side while you are holding straight can be corrected without touching the mechanics. It is the first adjustment anybody learns and the one most often used to hide a real problem.
In practice
Trim is adjusted with buttons or levers next to the sticks. On steering, the correct method is to first get the linkage mechanically close — turnbuckles adjusted so the wheels sit straight with the servo centred — and use trim only for the last small amount.
Worth knowing
Large amounts of trim mean the linkage is wrong, and you are paying for it with unequal steering lock in each direction. Fix the mechanics and reset trim to centre.