Rudder trim wheel

[SantaPaulaCTSW]

Hi. Noticed recently that when I trim the rudder all the way to the right with the rudder trim wheel, the trim indicator inside the plane does not go past neutral and seems to just be real loose beyond that point. I checked what was happening outside with the actual rudder when I roll the rudder trim wheel all the way to the right, and the actual rudder seems to stay in the neutral position as well. Then I rolled the rudder trim wheel all the way to the left, and the indicator moved all the way to the left inside the plane and the actual rudder also moves left. Hmmmmm. So it seems I have no right rudder trim to speak of. Hmmm. Any thoughts what is going on here?

 

Thanks,

Robin

[Roger Lee]

Hi Robin,

 

First the front wheel should be off the ground as this will affect that trim movement. Then you need to go back to the rudder and see if it has the proper left and right trim pressure. The rudder pedals here must be held firm in one position. Check to see if the rudder has approx. 21-24 lbs. of pressure left then right. Your cables could be loose or was never really adjusted correctly. (no matter how old the plane is) If the trim wheel moves all the way to the right and the indicator does not move it could be lose. The indicator is just screwed into a receptacle which holds it firmly around a cable. If it is lose then it may not move. Grab the indicator with a pair of needlenose pliers and see if it moves on its own without the wheel.

[SantaPaulaCTSW]

Hi Roger.  I can move the indicator to the right with my fingers, then it just sits there when I move the wheel to the left towards neutral.. 

 

Robin

[Roger Lee]

Hi Robin,

 

Then the chrome part sticking up needs to be tightened down. Move the wheel left and right and get an idea where center is. Then move the indicator center. You can reach into the indicator slot with a small set of needlenose pliers and hold the brass base then just tighten the chrome indicator part. Do not wrench down on this as you could cut the twine like cable it threads that thread through it. Just snug is good.

[FlyingMonkey]

Does the rudder trim actually work when flying?  If you make a big change to rudder trim can you swing the ball out with it?  If there is too much slack in the rudder cables, I could see where there might not be enough range in the trim system to make any real change to the rudder.

 

I had a problem with aileron trim a couple of years ago.  By accident I found the trim cable on one side had loosened and slipped off the pivot point, so the trim was not properly biasing the control system.  We slipped the cable back on the attach point and re-tightened everything and it was good to go.  

[Tom Baker]

Personally am not to worried about the trim indicator, like Roger said it can come loose. If the trim doesn't work correctly in flight you need to look back in the tunnel and make sure the rudder cables are routed over the pulleys on the trim mechanism. This area is a little hard to access, but remove the tray behind the throttle and follow the rudder cables back into the fuselage. You should see each cable go over a pulley. If both do not go over their respective pulleys the trim will not work correctly.

[Roger Lee]

To me the actual indicator means nothing. You are going to turn the wheel until it's trimmed right no matter where the indicator is. If it trims in flight who really cares where the indicator is. You don't fly the indicator you fly the actual trim.

[Runtoeat]

This has been discussed.  See the post and picture of the trim cable inside the tunnel:

http://ctflier.com/index.php?/topic/2623-checking-rudder-trim-movement/?p=41646

[SantaPaulaCTSW]

Thanks all.