Elevator trim tab deflection

I have just visited a mates build and noticed that although he has an electric elevator trim, he has elected to use the manual trim configuration on the Trim Tab Horn and not the electric trim tab horn configuration as depicted on the plans.

I rushed home to try my configuration with the servo inserted and the pushrod/linkage attached to the trim tab horn (electric configuration of course).

What amount of trim tab deflection SHOULD I expect (up and down) from this configuration?

Wayne

HEY folks, surely someone out there has electric trim on their elevator. All I need is a measurement of the full deflection angles of the trim tab!

I'd have to measure at the hangar tonight. It's on the order of 15 to 20 degrees in both directions, full deflection with the servo.
In practice I only ever use about 5 degrees down deflection and maybe a couple of degrees up in flight.

It's very sensitive, and the shortest burst of up/down on the servo goes from almost right to not good enough. I can trim well enough to make the autopilot happy.

Thanks chip

Where it matters is on landing. On my -9A, full flaps and single pilot, I need a full down tab deflection. I suspect the electric servo has a much different throw than the manual cable, thus the difference in the shape of the horn. I'd be careful in not following the plans. There is a difference for a reason.

...thus the difference in the shape of the horn.

Thanks Mike, but I am confused by what I see on the plans! Confirm you used the pre drilled hole on the control horn closest to the skin of the trim tab?

I believe, according to my understanding of the plans, the hole furtherest away from the tab skin gets trimmed away- this is if you want to install an electric trim .