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Spring Aileron Trim and Stick Pressure

C

Clouddancer

Well Known Member
I wondered if there is anybody who has flown his RV with and without the Vans spring aileron trim system? Is there any difference in stick pressure in flight with the added springs? I can imagine that the the feel might not be so light any more.

I'm building an RV-4 without autopilot. Is an aileron trim recommended or is it only a nice-to-have?

You may have noticed that I'm struggling to decide if I should incorporate a an aileron trim or not. It would be a spring based system, as I have no trim tab on the aileron.
 
On my 8A

I have flown without my aileron trim hooked up during flight testing. I had a heavy wing so I disconnected the trim during the fix to make sure I was just fixing the heavy wing problem without any interference from the trim system, seems like a good idea to me. In reguards to flying without aileron trim, that would not be for me. Fuel burn is going to affect roll trim, I like to keep my plane in trim as much as I can. Maybe it is just the way I fly but I am constantly playing with my trim after changes in power settings, wouldn't like flying without it.

Randy
8A
 
I didn't install the aileron trim before the first flights. I guess my thought was to see how the plane flew without it. (ie: heavy wing) During phase 1, I installed it, because I knew I was going to be flying long cross countries and the trim would help with the fuel imbalance. Van was right, it does.
 
I liked the spring aileron trim and did not notice any change in stick force to use it. One mistake I made when I originally installed it was to stretch the springs out and I had a lot of tension on them. Later before I finished construction on the plane, I added safety wire loops to the springs to relieve the tension. I set the system up so there was very little tension on the springs when in neutral and the sticks were barely held vertical when in neutral. Changing the position of the lever would induce enough force on the sticks to move them and trim the plane. Not much force is needed to trim.

Roberta
 
I installed one in my RV-4. It is very useful for cross country to account for fuel burn. I flew for about 10 hours before installing it. There is a SLIGHT difference in control feel from the springs, mostly in roll, but also a bit in pitch.
 
I never connect the springs during initial flight testing. I want to see how she flies and make sure the springs are not part of a possible heavy wing indication.

Pat
 
I didn't install any aileron trim, don't miss it, and don't find fuel balance to be an issue.
 
I've disconnected my system for first flight and, frankly, I'm wondering why I installed it in the first place. Given the very minute stick force necessary to effect change and assuming proper fuel tank management, is it necessary? I guess I'll find out.
 
DanH said:
I didn't install any aileron trim, don't miss it, and don't find fuel balance to be an issue.
Click to expand...

I'm with Dan on this one, installed the mechanism during the build but removed the springs for flight test, never felt the need to re-install.
 
For my 6, I installed the servo operated trim tab method. I do not like bias springs.... period. Even though required pressure to keep level is light, I really enjoy keeping the 6 in perfect trim with just a touch on the hat switch button.

L.Adamson
 
spring trim

L.Adamson said:
For my 6, I installed the servo operated trim tab method. I do not like bias springs.... period. Even though required pressure to keep level is light, I really enjoy keeping the 6 in perfect trim with just a touch on the hat switch button.

L.Adamson
Click to expand...

Why don't you like the spring trim system?? Courious...
 
NickAir said:
Why don't you like the spring trim system?? Courious...
Click to expand...

I don't mind rivets on trim tabs on airplanes. My mind is more of the WWII fighter era. I prefer airloads on flight surfaces balancing themselves, instead of spring tension. Two "spring" builder owners, really do like the feel and operation of the servo operated tabs on my plane.

I love the system myself. I have a hat switch on the stick for both elevator and aileron (not WWII:)). I'd never trade it for manual or bias spring operation. I'd never use a spring system for rudder trim, as I prefer the tab, and trimmable tab even more..........but that's just me.

L.Adamson
 
Trim

OK, thanks for the clear explanation on RV trim. I am also on the same page as your explanations.
 
I installed it

I installed it tested it and it works fine. I don't notice it being there and since I now have an autopilot I never even think of it being there except when I have to remove the lever to remove the seat pans. I guess it still serves a centering function against gusts, etc. When flying for a year before the autopilot I occasionally used it for fuel burn offset and it performed as advertised with no adverse effects that I could sense. However, recently I have read of experiences where builders thought that clecoe pliers were hard to operate so experiences do differ.

Bob Axsom
 
However, recently I have read of experiences where builders thought that clecoe pliers were hard to operate so experiences do differ.
Click to expand...

Now THAT'S funny!! I needed a good belly laugh, thanks Bob!! :)
 
Thanks for all the responses. As it looks, experiences and preferences do really differ. A good point I have not yet thought of, is to disconnect it for flight testing, as several of you mentioned.

So, I do hesitate now whether to install one and leave it disconnected if I don't like it or to install one after flight testing if I feel the need for it:confused:
 
It is very easy to install later. You just need to be sure if you make a stick boot to leave enough room for the mechanism and lever.
 
DanH said:
I didn't install any aileron trim, don't miss it, and don't find fuel balance to be an issue.
Click to expand...

Second this, though I didn't build. I burn 30 mins a side. There is a slight imbalance noticeable sometimes, not enough to make me consider adding a trim system
 
RV-8 aileron trim in RV-4

I thought of installing the electrical spring aileron trim as it can be bought from Vans for the RV-8. I saw one of them installed in a rocket. I already have a hat buttom on the stick for the electrical elevator trim that I could use for the aileron as well. It's a bit more complicated than the original RV-4 system with the lever on the stick. But it somehow looks more appealing. :rolleyes:
 
walkman said:
Second this, though I didn't build. I burn 30 mins a side. There is a slight imbalance noticeable sometimes, not enough to make me consider adding a trim system
Click to expand...

On the otherhand..............if you already had it installed, I bet you'd use it all the time. I'd do 30 mins a side also. But I always have this habit of having perfect trim, since the means to do so, is readily available.

L.Adamson --- RV6A/electric trim for both roll & pitch/on the stick hat switch
 
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