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Fixed Rudder Trim Tab

rvanstory

Well Known Member
8 hours into Phase 1 flight testing. It looks like I will need a trim tab to center the ball in flight. I am going to do a "fixed tab" on rudder trailing edge. (not looking for advice on electronic or spring actuated options).

Does anyone have pictures of their fixed rudder trim tab they can post for me? Looking to see how big you made it (dimensions) and how you attached it (rivets on trailing edge only, rivets on stringers, ProSeal, etc...)?
 
I used about 14" or less of the triangular shaped stock that is included for rudder/elevator trailing edge. Currently held on with Al tape until I paint it and affix it with silicone. I pretty much aligned the thick end with the rudder trailing edge and was sure I was high enough to be in un-disturbed air flow

A thicker wedge, with a greater angle would be shorter. I like this one because it blends in very well, even though it is long. The wedge on my 6 was affixed with silicone and is holding strong after 650 hours.

Larry
 
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Before you add a tab, recommend flying without wheel pants or gear leg fairings to make sure you are not inducing your trim issue. I found the rigging on the RV-10 to be very sensitive to these and a little off can put the ball half out.

Here is a simple tab if you just need a little. Easy to try without anything permanent done the rudder.

Carl
968-E98-B6-F9-F1-4883-985-B-2-D3-D98-A5-EB56.jpg
 
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Have you triple checked nose wheel break-out force?

An air-to-air picture showed me our nose gear was deflected in level flight which was the cause of my half-ball deflection.
 
Here is what mine looks like. I too purchased the one from Cleveland and it works really well. I attached it with proseal.
 

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I have always liked the trim tabs on Tomahawks. It is a piece of maybe 22 gauge about 5" tall and extending 2' past the rudder trailing edge (5"X 3" actual dimentions is my guess). It is rivited to the trailing edge (could be pro-sealed). You can then bend it to adjust trim. If something changes in your trim or flying, it is easy to re-adjust.
 
Major thread drift - but that is a really nice paint job!!!

Lol - thanks. Jonathan at Plane Schemer did the design with me and Lancaster Aero just completed my paint last week. It’s been turning heads for sure!
 
I like this idea of the wedge, but does this maintain trim from idle to full power?
only trims like this I have messed with are on 172s that are bent and they never seem to be helpful. I liked the adjustable type but I hate constant changes in rudder and would like to avoid if possible. Thanks
 
I like this idea of the wedge, but does this maintain trim from idle to full power?
only trims like this I have messed with are on 172s that are bent and they never seem to be helpful. I liked the adjustable type but I hate constant changes in rudder and would like to avoid if possible. Thanks

I have a wedge (Carl is right, I know the out of trim condx is due to my gear or gear leg fairings - the plane flew ball-centered before I put them on. But I can’t find the exact cause.). I do have to hold right rudder in a climb. But in cruise the ball stays centered over all the cruise speeds I use.
 
Is this a good time to ask which rudder trim option produces the least amount of drag per "unit" of rudder trim?
The internal option is the obvious winner, buy what's in second place, the fixed tab or the wedge?

Cheers, David
RV-6A KBTF
 
I have a wedge (Carl is right, I know the out of trim condx is due to my gear or gear leg fairings - the plane flew ball-centered before I put them on. But I can’t find the exact cause.). I do have to hold right rudder in a climb. But in cruise the ball stays centered over all the cruise speeds I use.

Thanks that does answer my question
 
Or Tweak the Rudder Pedal Springs

I've been known to shorten a rudder pedal return spring if the ball is not too far out of shape.
 
I like this idea of the wedge, but does this maintain trim from idle to full power? Thanks

No. A fixed trim tab is generally set to put the ball in the center at your "typical" cruise setting. All other conditions (climb, descent, slow flight, etc) will require some rudder input.
 
We had an early RV6 with floor mounted rudder pedals, it had return springs basically to stop the pedals from flopping toward the pilot/copilot. Not really an issue with overhead mounted pedals From memory shortening them would only be very limited help with centering the ball, as was said........ This has been on the 10 forum before, but we have good quality boating cord from the rear of right hand pilots pedal and the rear of left hand copilots pedal to the firewall, through a small pulley on each side and then back to easily reached Harken Micro Cam-Matic Cleats, one one each side of the tunnel. This setup serves two purposes. 1/ The rudder can easily be locked before you leave the pilots seat for refueling parking etc by centering the pedals then securing both cords in the left and right cleats, that saves the big 10 rudder crashing around unrestrained. 2/ Rudder trim can be initiated in flight by centering the ball and then applying retaining pressure on one side (usually the right pedal but not always). As soon as you put your feet on the pedals you know they are restrained so releasing them which is just a quick flick of the cord has never been an issue on the ground or in the air. Of course enough slack is left on both sides to allow full rudder travel when not engaged.
 
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