Setting Trim Calibration D-180

[Piper J3]

I’ve been reading Van’s instructions and Dynon Install and User manuals to find out how to set calibration for D-180 elevator trim indicator. It says to set limits for full down and full up and then set a bug for takeoff position.

When flying the RV-12 the amount of trim used for normal flight is only a small percentage of the total range available from the electric servo. Wouldn’t it be better to tailor the scale of the trim indicator to fit the usable range of the trim tab as described by normal flight? This would make the trim indicator more sensitive and give a better graphic depiction of actual amount of trim being used.

Any advice appreciated…

Piper J3

’46 Cub owned for 23 years - sold in partial trade for flying RV-12 with 50TT

 

[BigJohn]

When flying the RV-12 the amount of trim used for normal flight is only a small percentage of the total range available from the electric servo. Wouldn?t it be better to tailor the scale of the trim indicator to fit the usable range of the trim tab as described by normal flight? This would make the trim indicator more sensitive and give a better graphic depiction of actual amount of trim being used.

If you set the indicator to show only the middle range of travel how will you know if the trim has been run all the way to one extreme or the other? If you want more sensitivity to the trim switch why dont you just adjust the servo to run faster?

 

[JBPILOT]

Just did this for someone else - -

Run it to both ends like the screen directs you to do. Find out what trim position you like best for takeoff. If you have a long enough runway, just land without adjusting further and get back into trim screen and set that for takeoff. I didn't try it, but guessing you could leave that screen up, and set it for takeoff and see what number it displays. Once on the ground, set it to that as takeoff position.

I have found I like the takeoff position for landing also. When you are ready to takeoff next time, it is already set.

 

[Piper J3]

Your point is well taken. I will set it for full scale.

Thanks for enlightenment...

 

[rvbuilder2002]

In addition to what John and John said.....

The only time you will look at the indicator is when setting for takeoff, and even that is an approximation to get it close. When in flight you adjust to get the force you want, not the indication on the screen. This is really no different from any airplane (even a cub).