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Rudder Trim RV-10

D

djc527

Member
I am hoping someone on this thread can give me some useful information reguarding my RV10

I am in phase I testing of my RV10. I need to depress the right rudder pedal about 1 inch to center the ball in cruise flight. It is the same with or without the gear leg fairings and wheel pants. This is a quick build kit. I can correct the problem with a "large" rudder trim tab (10 inch piece of 3/4 angle aluminum duct taped like a tent parallel the the trailing edge of the lower rudder). I spoke with Ken at Vans who felt like this was quite a bit of rudder trim tab. Can anyone give me ideas of what I might need to check. I am in southern California. Can anyone recommend someone knowledgable who is in my area?

When I have the autopilot engaged on a straight and level heading at cruise without rudder trim tab the ball is to the right and the airplane is slightly banked to the right (crosscontrolled). Depressing the right rudder to center the ball levels the wings.

Thanks
 
Check the alignment of your wheel pants and gear leg fairings. Have somebody fly behind you to confirm the nose gear isn't cocked over to one side. I've seen that more than once...
 
Rudder trim

I have an RV 10 with the same problem. My tab is quite large because it requires a big foot to center without the tab. Probably a whole ball off.
I had a 7A that needed virtually no trim tab at all. I think it is the nature of the 10. As far as I can tell, I am pretty evenly trimmed out, though I have not had someone watch me in flight.
 
Seen this in another -10 as well. Maybe those with lots of hours in them should sound off and let us know if this is present in all examples? Do we need to change fin offset a bit maybe?
 
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rv 10 rudder trim tab

I saw the same right rudder requirement in mine...I installed a rudder trim tab
Son
RV10 70 hrs
 
Hmmmm

Just to provide another data point, my 10 flies with the ball in the middle. As you probably already know, many RV's require a trim tab on the trailing edge of the rudder, I agree that the one you describe sounds on the large side. I liked what Dan said about your nose wheel/fairing possibly being cocked but I think you stated that that the condition is the same with OR without the pants and fairings??
 
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Response to HMMM

Thanks everyone for your input. I hate to resort to a trim tab if there is something fixable.
 
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I had the same problem with the 9A rudder. I cured my problem by massaging the trailing edge by hand. Start at the top and with thumbs and fingers gently try bending the trailing edge to the left, all the way down. It's stiffer and tougher than it looks, and takes more pressure than one would think to actually put a slight offset in it, but it is very effective. Might need several passes down the trailing edge to get what is needed. The end result can't be seen, but worked well for me. (I removed a 6" wedge tab afterwards).
 
Rudder trim tab

I've flown mine now about 45 hours and I'm experiencing the same problem. I tried to attach a trim tab I bought and it helped a little, about half a ball. I plan on attacking this as soon as it gets back from the paint shop. I think Tim O told me he had the same problem and ended up making a trim tab to correct it.

I have the same results when I center the ball with right rudder, it raises the right wing back up to level. :rolleyes:

Wayne Edgerton N602WT

In the paint shop
 
I have 140 hours on my RV-10. The plane required right rudder to center the ball. After attaching an A/S rudder trim block (used double sided auto molding tape) placed about the middle of the rudder the ball went out to the left. I'm now triming the block down in stages and the ball is slowly but surely moving to the center.

Mark
RV-10/N410MR
 
Mine required the right trim as well, as do most of them. I vaguely remember hearing that when Van's was experimenting with the smaller engine, they centered the vertical fin, and then it never got moved back once the larger engine was decided upon. Hence the need for the right trim. That's why I built a new rudder and added electric trim---- the ball is now centered at all speeds and altitudes. :)

There's a lot of stuff that can affect the need for rudder trim, too. Don't hesitate to adjust L&R flap settings and adjusting the trailing edges of the ailerons by squeezing them, which usually helps in offsetting a heavy wing as well.

vic
 
Rudder Trim RV 10

I've just ordered the Tail for the RV 10. I want electric rudder trim, do I need to purchase this and install as I build the rudder? Once built is it to late to add?

Dave
 
Murfonline said:
I've just ordered the Tail for the RV 10. I want electric rudder trim, do I need to purchase this and install as I build the rudder? Once built is it to late to add?

Dave
Click to expand...

As you can read on Tim's site (http://myrv10.com/N104CD/upgrades/20071104/index.html) he can be added at any time. However, adding it when you are assembling your rudder is much easier.

Since you're new to the RV-10 world, I would highly recommend that you register on Tim's site as a RV-10 builder. You'll find many things of interest common to RV-10 builders on the site.
 
Murfonline said:
Do I need to purchase this and install as I build the rudder?

Dave
Click to expand...

Dave,

Currently there isn't a "kit' or commercially available rudder trim. Vic's is explained on Tim's site and some of us are working on an alternative trim system. One thing for sure as Bob pointed out, it's way easier to do during assembly, then on the other hand if you are new to metal work you may find it tougher to do at this point of your build unless your comfortable cutting out access panels and laying up access hole reinforcement and nutplates from scratch. Not hard but seemed like a piece of cake after building the majority of the rest of the airframe.
 
Modified L Brackets

I'm adding rudder trim to mine and very closely following Vic's design.

I did run into an issue with the bottom of the clevis running into the L-brackets when fully extented. The only options were to build narrower brakets, remove some material from the bottom of the clevis, or offset the hole closer to the edge of the bracket. None of these options made me very excited.

So I woke up yesterday morning with a modified design of the brackets in my head. This allows for a greater angle of rotation, keeps good clearance on the hole, and doesn't require removal of clevis material.

I built these out of .040. Thought you might like to see them, if you're considering the addition of rudder trim.

Phil


DSC_2826.jpg


DSC_2827.jpg
 
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Phil said:
I'm adding rudder trim to mine and very closely following Vic's design.

I did run into an issue with the bottom of the clevis running into the L-brackets when fully extented. The only options were to build narrower brakets, remove some material from the bottom of the clevis, or offset the hole closer to the edge of the bracket. None of these options made me very excited.

So I woke up yesterday morning with a modified design of the brackets in my head. This allows for a greater angle of rotation, keeps good clearance on the hole, and doesn't require removal of clevis material.

I built these out of .040. Thought you might like to see them, if you're considering the addition of rudder trim.

Phil
Click to expand...

Phil, I like your design. I think I'll re-make mine and copy your design.
 
Rick S. said:
Dave,

Currently there isn't a "kit' or commercially available rudder trim. Vic's is explained on Tim's site and some of us are working on an alternative trim system. One thing for sure as Bob pointed out, it's way easier to do during assembly, then on the other hand if you are new to metal work you may find it tougher to do at this point of your build unless your comfortable cutting out access panels and laying up access hole reinforcement and nutplates from scratch. Not hard but seemed like a piece of cake after building the majority of the rest of the airframe.
Click to expand...

I will admit this was a little daunting for me as a newbie too. I bugged Vic, Tim, and a couple others before I actually cut into the rudder skin. The issues that I was experiencing was the none of the various sets of measurements yielded to what I thought was an appropriate location. I think Tim did a great job describing this in his write up. It doesn't really matter, just get it centered between the ribs.

The other interesting observation is to look how folks mounted the fairing covering the hole that the arm passes through. I made mine so that it is aligned in a fashion that is more parallel to the ground. I was concerned that if it's angled upward, it would server as a rain funnel.

I don't have any good pictures of this on my site, but could take some if interested.
 
So, are you guys using the VA-195C, and D parts for the servo mounts??

Has anyone used the electric trim kit Vans sells as part EE-KIT/servo?? It is designed for the elevator in later kits, appears to be very adaptable to the 10 rudder.

By the way, a friend and I have put a rudder trim in his 10, mounts in the tunnel between the rear seats, using springs to bias the cables------still some bugs to work out, so far it is pretty ineffective.

I will post details if/when it all gets sorted out, no sense in putting it up here until I am sure it will work.
 
Mike S said:
So, are you guys using the VA-195C, and D parts for the servo mounts??
Click to expand...
When I did mine, I didn't know about the VA-195C and D. I SURE WISH I HAD KNOWN ABOUT IT BEFORE I CUT MY SKIN. I did an OK job but not up to what I expect my quality to be. I would advise anyone doing the Vic rudder trim to get these 2 parts and use them for the cover and the nut plate mount/backing. It will look so much more professional.
 
Rudder Trim

Working on a spring bias system attached to the rudder pedals..........can be mechanical or use a servo. Can apply left or right rudder trim without messing up the rudder with a fixed TAB or ugly hinge....... plus no added weight/electrical.

Also recently extended the T handle 2 1/4 inches on the seat adjuster. Much easy to reach and adjust seat versus stock handle. No more trying to get your hand down between the seat and sidewall fishing for the T handle. Will try to post a pic when I get the right seat done too.

Dean 805HL
 
I wasn't planning on using it, but I had a similar design in my head. I just hadn't put it on metal yet.

When I get back to the house tonight, I'll take a little closer look and see if I can work work it into the trim instead.

I'll try and get some photos to share.

For the record, I'm working very slowly right now. I really want it to look nice when it's done and avoid any nasty cosmetic mistakes. So don't expect too much too soon, but I'll post them up.

Phil
 
ddddsp said:
Working on a spring bias system attached to the rudder pedals..........can be mechanical or use a servo. Can apply left or right rudder trim without messing up the rudder with a fixed TAB or ugly hinge....... plus no added weight/electrical.

Also recently extended the T handle 2 1/4 inches on the seat adjuster. Much easy to reach and adjust seat versus stock handle. No more trying to get your hand down between the seat and sidewall fishing for the T handle. Will try to post a pic when I get the right seat done too.

Dean 805HL
Click to expand...

The spring bias thing sounded really neat at first, but the more I think about it, and the more we play with it, the less I feel it is going to be the way to go. Problem IMHO is that unlike the ailerons, there is no opposing force input into the system. The rudder aerodynamic load must be overcome with the springs only. By the time there is enough spring tension, the pedal feel may be more than folks want to deal with.

I am glad, however that others are going down the same path, maybe one of us will trip over the solution.

As to the seat slide "T" handle, there was a post a long time ago from someone making a unit that brought the handle around to the front of the seat, like in your car. IIRC, looked nice, but kinda high $$$.

Your idea of just extending it vertically sounds interesting.

Keep on with the ideas.
 
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