There seems to be quite a bit of discussion over the last few days whether the carb. return spring should be disconnected or not. It was a slow day here today with Obama in town (can't go fly until he leaves the area) so I thought I'd dig out a few servos and carbs, jig up a test fixture and actually measure how much current is required to hold a throttle at full on position when the spring is in place. Also, I tried to come up with a few comparisons as a measure of how much power is required. Keep in mind this is at full throttle and though I didn't make a column for half throttle, the current draw was considerably less at partial open positions.

This is a purely unscientific test but the numbers don't lie. The servo current required to overcome the spring tension is very low by any comparison. In fact so low that if you can hear your digital servos buzzing they might be drawing more current than if they were connected to a spring in place. I'm sure that just sitting on the ground, if you have large control surfaces, those servos are probably drawing more current than the throttle servo with a spring in place.

I don't expect much comment about this as charts and facts rarely produce much of a discussion in the forums and I'll leave it at that.

Edit: PDF upload finally successful!