giovanniluigi
New member
I suspect there may be a systematic error in Evolution (and possibly even earlier versions') software radio calculations. Specifically, when an input has scaling applied, then the output seems to have an unwanted dependence on a non-zero expo value.
For example, using a stock Extra 300L in high rates, consider a rudder “Output Channel 4”, with Input being “Input Channel 4 (Left Stick, X Axis)” ranging from -100% to +100%. Set the input scaling Percent (%) = 80 and the Output should range +/-80%. It does so, if “Expo During High Rates (%)” is set to 0, but when this expo is set for anything different than 0%, e.g. 40%, then the output ranges less than +/-80% (the specific amount being dependent on the expo percentage), in this case +/- 63.9%.
In my experience with real radios, such as Futaba, PowerBox, etc., any amount of Expo results in the travel endpoints being unchanged from those with a 0% expo (i.e. the linear curve). In other words, the expo % is not equivalent to "scaling", but to "shaping" the output according with an exponential curve, where the expo % only relates to how much the curve deviates (normally lower) from linear around the center, to desensitize the input from small movements of the stick, leaving the endpoints unchanged. The rate value (e.g. high rate, low rates, etc.) is the one that can affect the travel endpoints, not the expo value.
Am I missing something?
For example, using a stock Extra 300L in high rates, consider a rudder “Output Channel 4”, with Input being “Input Channel 4 (Left Stick, X Axis)” ranging from -100% to +100%. Set the input scaling Percent (%) = 80 and the Output should range +/-80%. It does so, if “Expo During High Rates (%)” is set to 0, but when this expo is set for anything different than 0%, e.g. 40%, then the output ranges less than +/-80% (the specific amount being dependent on the expo percentage), in this case +/- 63.9%.
In my experience with real radios, such as Futaba, PowerBox, etc., any amount of Expo results in the travel endpoints being unchanged from those with a 0% expo (i.e. the linear curve). In other words, the expo % is not equivalent to "scaling", but to "shaping" the output according with an exponential curve, where the expo % only relates to how much the curve deviates (normally lower) from linear around the center, to desensitize the input from small movements of the stick, leaving the endpoints unchanged. The rate value (e.g. high rate, low rates, etc.) is the one that can affect the travel endpoints, not the expo value.
Am I missing something?