Rudder stops and rudder deflection

[Foghorn]

Originally Posted by wirejock

I installed the Flyboy rudder stop. No external stops. I haven't fine tuned them but the swing looks pretty close.

Larry,

I installed mine the week after OSH. Nice out of the way installation. They?re very hard to file down so I used a small dremel taking a little at a time.

Jeff

[JurgenRoeland]

Thanks everybody for the tips. It's clear that my measuring method was wrong. I'll give it a try with the floor method and the centerline with clecoes method as mentioned above.

I asked the question also to Vans support and got the following typical funny answer :

"The acceptable range is 30-35 degrees (ref section 15).
However - forget all that. The best way to measure it is to keep the gap between the elevators and rudder skin to >1". That is much easier to measure. No one will care about the "correct" travel if they have a hole punched in the rudder skin...."

[RV7A Flyer]

Internal stops here, work great, and proper distance from elevator per plans.

[rightrudder]

Originally Posted by JurgenRoeland

Thanks everybody for the tips. It's clear that my measuring method was wrong. I'll give it a try with the floor method and the centerline with clecoes method as mentioned above.

I asked the question also to Vans support and got the following typical funny answer :

"The acceptable range is 30-35 degrees (ref section 15).
However - forget all that. The best way to measure it is to keep the gap between the elevators and rudder skin to >1". That is much easier to measure. No one will care about the "correct" travel if they have a hole punched in the rudder skin...."

So true. I swung the rudder to within an inch of the elevator half, clamped it in place and made a cardboard template for the angle. Repeat for the other side. Cleco your stops in place and make sure you truly still have an inch of clearance; then rivet. Too easy to overthink this!

[pilotkms]

An RV14A at OSH this year with internal rudder stops got wind damaged - rudder swung into the elevator on the right side, at least.

[RV7A Flyer]

Originally Posted by pilotkms

An RV14A at OSH this year with internal rudder stops got wind damaged - rudder swung into the elevator on the right side, at least.

Did this happen a) while parked and tied down, b) prior to that but with nobody in the cockpit (e.g., while pushing back or pulling out of parking space), or c) while taxiing?

[pilotkms]

It was parked at HBC, Tied down, Tail was facing west. Friday nite?s storm blew heavily from the west. Thought the owner would see this and post the details.
I was parked nearby, facing same direction and no damage. I have externals on my 7A.

[RV7A Flyer]

Originally Posted by pilotkms

It was parked at HBC, Tied down, Tail was facing west. Friday nite?s storm blew heavily from the west. Thought the owner would see this and post the details.
I was parked nearby, facing same direction and no damage. I have externals on my 7A.

So the rudder gust lock failed.

[amaris]

I ended up fabricating my own, mainly because I botched the flyboy one and didn't want to spend another $35 for a piece of plastic. I used a nice 1/2" cutting board that came out of my grill side that I never used. Very dense and same HDPE plastic. The thicker piece allowed me to plane it down and fit it perfectly between the hinge bracket so no additional spacers were required. Since I had so much material left over, I fabricated an extra to keep as a spare in case something breaks or wears on the old one.

They're not that hard to make your own if you are also trying to save money.

[FinnFlyer]

For my RV-4 I 3-D printed internal rudder stops.

https://drive.google.com/open?id=1w_...lPHl-EwKv6ssgg

After looking for a long time to find "the plans" on the Internet, I designed my own in Fusion360.

I designed them to fit between the brackets (makes it slightly more difficult to drill the two mounting holes in the brackets).

I used Van's vert stab and rudder plans, but also measured the actual distance from vert stab to pivot point and from pivot point to rudder.
You want a 1" diameter hole around the pivot point to make room for the Heim bearing. Of course I messed up and measured the 35* angle at the pivot point instead off offsetting it out to the rudder and had to redo it.

Even so I had to trim it a bit.

If anyone wants to so this, my suggestion is to 3-D print the first couple of layers, stop and then see how it fits. Then adjust and reprint.

To measure deflection I used fuselage center line on floor, plumb bob through bracket holes. Then, with rudder mounted, plumb bob at tip of rudder. Either use a protractor or calculate distance from center line out to each side: distance-from-pivot-point-to-plumb-bob x sin(35). In my case about 11.5". Unfortunately the maximum deflection to the right seems to be limited by contact with elevators. Thus it appears you must design it for your airplane.

Finn