which servos for which airplanes

[N2ES]

I've flown many Lancair's (IV's and ES's) with TruTrak A/P, and have noticed that the some of the servos are not strong enough especially in roll. What servos are recommended for the IV (non turbine), and ES? Are there any downsides to installing the HB servos in all 3 axis? (other than weight of course). What is the cost of the HB servos compared to the others? If there is a chart that shows this that would be helpful for each type of airplane. Maybe you have it already and I missed it.

[TrutrakTech]

The Lancair IV piston uses our C servos in both axes. The ES uses our C servos as well. The IV turbine uses our HB servo for roll control. Technically, there is no downside to using the high torque servos in each position, other than the added cost. They cost $500 more than their standard servo counterparts. The weight difference in minimal, 1lb max.

We don't have a chart that shows what servos to use in each type of airplane because it's integrated into our ordering system. There's no way to separate it out.

For the planes that you have flown and observed a lack of torque, what were the symptoms? Did the users have the torque in the AP controller turned up to a sufficient level? Often times, I've noticed that users turn down the torque so that it is easier to override the AP. This handicaps the AP from being able to control the aircraft through it's full range of flight characteristics. I hope this helps!

[N2ES]

What I've seen is that they just won't hold a heading or track a nav signal very well. It starts to, then sort of wanders off. The most recent one was a Sorcerer in a IVP and yes the torque values were set to the max. The owner ended up having the higher torque servo and now it works fine. I don't know which servo was installed in the first place and I don't know which servo was the replacement. The owner had a shop do the work and he didn't know either. I know of at least two other IV's that replaced the servo for similar problems, but again I just don't know what was in there. This is one reason I asked the question because now I know at least the C models would be a baseline. I'm building a Turbo ES and have three servos installed. I have a B, C and D in the yaw damper, so looks like I will need to at least replace the B which is what I suspected. Is there a trade in policy for the servos? I'd like to trade them all for the clutch model HB. Thanks for the info.

[TrutrakTech]

It is possible that the other airplanes you mentioned needed to try moving the attachment point further in on the servo arm instead of using the outer hole.

There is a trade in policy, you simply pay the difference in price. We just need to know the voltage of the aircraft system as the HB servos are voltage specific.

PM me your contact info and I can get you an RMA# to return your servos for exchange, however the D servo will be more than enough for your rudder control. Thanks!