HS & VS rigging adjust during Phase 1

[BruceW]

Got a few flights into my Phase 1. Need to adjust rigging of the HS and VS.
Want to make adjustments to the rigging via shims vs. tabs.

Horizontal stabilizer; in cruise, the elevator is up (counterweight end is approx 1/8? down). So need to trim the HS forward spar up. Question is, how much to shim? Some may say, "put a shim in and test fly it?. I ask for someone with experience to give me a good starting point based on the 1/8? elevator off neutral. My guess is a .035 to .050 shim. But looking for some past experience to start.

Vertical Stabilizer; in cruise the ball is about 1/3 off to right. So I need to shift the VS forward spar to the left. Planning on drilling a new VS to HS connector plate to re-rig the VS. Same question, how much shift to left? My guess is 3/32? but again, looking for better info as a starting point.

Again, looking for someone with experience with this, not just forum speculation.
Thanks in advance.

 

[pierre smith]

Negative Bruce....

....you're going the wrong way with the stab.

The stab leading edge needs to come DOWN...thats the same as "up" elevator.

Best,

 

[Kevin Horton]

Based on the ratio of elevator area to HS area, you need to change the HS incidence angle by about 40% of the amount of elevator deflection you currently have. E.g., if the elevator is deflected 1 degree in cruise, you need to change the HS angle about 0.4 degrees to end up with close to neutral elevator.

 

[[email protected]]

chasing hairs here...

the elevator to horizontal stabilizer relationship for steady state in flight will move a bit with CG loading and airspeed... chasing an 1/8" in one condition by drilling new attachment parts... yikes...

you can move the ball around a remarkable amount by tweaking a gear leg fairing at the root attachment just a touch... i found that i could push the ball significantly with as little as 1/32" change in clamping a gear leg fairing.

 

[BruceW]

pierce:
Oops, OK I get it. If the elevator is up in cruise the HS forward spar needs to go down. Got it. So, how much???

Others;
Good idea on adjusting VS with gear leg fairings. But would like to avoid reworking the intersection fairings and wheel pants. The HS/VS fairing was left unfinished anticipating some adjustments.

 

[pierre smith]

Fly with a passenger..

...and then look at the elevator. Put 100 lbs back there and I bet your elevator may be level, if not slightly down, because your CG shifts rearward with a passenger.

Take about a 5" piece of .025 aluminum, 2" wide, bend it about ten degrees down the middle of its length and duct tape it to the left side of the rudder and go fly. Keep tweaking it until the ball is centered. Two dabs of silicon rubber will attach it for the life of the airplane I used a 7" wedge of wood, cut to 10 degrees for my -10...just right.

Best,