DSX12 Instruction & Programming Manual - MacGregor Industries

83: Trim SystemThe Trim System function adjusts the sensitivity of the 12Xtrim levers and the Flap and Aux trimmers. The standard digitaltrims are adjustable from 0–10 with 10 being the coarsestadjustment and 0 being trim off. Adjusting the digital trimvalues has no effect on the total trim travel, however, it affectsthe resolution of each trim input. When the value is set to 10,each click of trim adjusts the servo output by 10ms and thereare only 10 trim increments from center to each end. When setto 5, the output is changed 5ms per trim step and there are 20trim increments from center to each end. When set to 1, eachclick of trim changes the servo output by 1ms and there are100 trim increments. When set to 0 the trim levers cease tofunction effectively, turning off the trim function. The Flap andAux Trimmers are adjustable from 0 to 200 and can be turnedon/off. When adjusted to above 100% the trimmer functions asa two- or three-position switch. Reducing the value increasesthe number of output positions. The trimmers can also be set tofunction as a momentary switch by selecting ON under Momentfor either or both trimmers. When adjusting the digital trims(AILE, ELEV, RUDD), the total trim travel does not change –only the number of increments (beeps) changes, which makesfor finer or coarser trim movements. When adjusting the analogthrottle trim, however, the total trim travel is actually reducedwhen set to less than 100%. Use a fairly coarse setting, such asthe factory default 4, when test flying a model for the first flightsin order to be able to trim it quickly; use a finer setting, such as3–1, for final precision trimming.When adjusting the digital trims (AILE, ELEV, RUDD), the totaltrim travel does not change – only the number of increments(beeps) changes, which makes for finer or coarser trimmovements. When adjusting the analog throttle trim, however,the total trim travel is actually reduced when set to less than100%.Use a fairly coarse setting, such as the factory default 4, whentest flying a model for the first flights in order to be able to trimit quickly; use a finer setting, such as 3–1, for final precisiontrimming.L.S.T. Trim (Limited Standard Trim)The L.S.T. trim feature has two options: L.S.T. and normal. Innormal, when making trim changes using the aileron, elevatoror rudder digital trims, the center as well as the endpoints isaffected by the trim values. The right trim causes the center,the right endpoint and the left endpoint to all shift to theright. When L.S.T. is activated, only the center position istrimmed. The center is shifted to the right but the endpointsare not affected. This is useful for aircraft that have a hard stopendpoint to prevent over-travel caused by trim or if it’s desiredto have trim changes not affect the total roll pitch or yaw rate.A-13