What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Aileron trim question.

bret

bret

Well Known Member
Looking to get a feel for who has or has not installed the trim, manual or electric. If so, do you use it, does it work, I will have AP so I don't know if it is even worth the effort? Thanks.
 
I have the manual roll trim in my -6. It has worked great for many years.
Initially you may need to tweak the tension of the springs and the tension on the bearing block to get everything just right.

I switch tanks every 5 gallons so I use it very little, but it is very handy.

Even with auto pilot you may need the trim. The A/P won't be on 100% of the time. And if you let the airplane get out of balance, the A/P may ask for trim anyway.
 
Last edited:
I have manual trim in my -8. I think it is useful at times and has no deleterious effect. One change I made was to open holes in the flooring large enough for a socket and extension. That way I can pull the cap plugs out and adjust tension on the block without removing the floor.

Don
 
cfiidon said:
One change I made was to open holes in the flooring large enough for a socket and extension. That way I can pull the cap plugs out and adjust tension on the block without removing the floor.
Click to expand...

Dang! That's a great idea (... why didn't I think of that?) Gonna do that during my annual in April.
 
Another thing to add:

I noticed that my auto pilot would wobble the wings trying to maintain a heading or track. I think it did this because it was wing heavy. Adding some trim took the wobble away.

Your mileage may vary...

Don
 
Funny thing.
I went through the same thoughts on Aileron trim.
I ended up putting in electric trim. When doing Phase one I thought the ailerons were tighter than other RV's. I went through the system to find the binding. I never did like the feel of the springs in tension so I didsconnected then for testing. I have not reconnected them and don't know if I will.
Don't miss the trim at all. If I want to fly hands off I will just engage the AP.
The pitch trim is a different story.
 
Looks like the AP may NEED the trim? gess I will put it in. Saw some one on here use RC linkage instead of the wire method. might look into that.
 
Aileron trim = must have.

Van's aileron trim is too simplistic in its design because one spring is always working against the other.

The Glasair III has a nice spring cartridge system for aileron trim, and I intend to duplicate this into an electric version for my rocket.
 
If I was doing it again, it would still be the servo operated trim tab, out on the aileron..........as Van's did in the past. No bias springs, which I never cared for. And I certainly believe in trim, since I like even forces, in order to keep the airplane level. I don't want an A/P motor in motion, to do what should be done in the first place. Note: My 6A aileron trim was due to passenger & fuel. Other than that, it was a well rigged airplane.
 
Ok, who has pics of the aileron trim tab? Just curious, is it similar to the elevator? On a different note, do you pre load, stretch, the springs so that there is no spring flopping around with opposite deflection?
 
MarkW said:
Bret,
I believe there are a couple of diffrent ways done in the past.
Either like the levator trim or a seperate tab hanging off the back.
http://www.vansairforce.com/community/showthread.php?t=64641
http://www.vansairforce.net/buildermods.htm
And yes the springs are pre-loaded per the instructions. It was this pre-load that I did not like the feel of. I need to reconnect mine but play with different tensions.
Click to expand...

The controls are so light on RVs that the preload on the springs can be adjusted so light that most people won't even notice it.
It is even less noticeable than autopilot servo loads.
 
MarkW said:
Bret,
I believe there are a couple of diffrent ways done in the past.
Either like the levator trim or a seperate tab hanging off the back.
http://www.vansairforce.com/community/showthread.php?t=64641

http://www.vansairforce.net/buildermods.htm

And yes the springs are pre-loaded per the instructions. It was this pre-load that I did not like the feel of. I need to reconnect mine but play with different tensions.
Click to expand...


OK, now the gears are turning, I like what Paul did. Has anyone else copied his trim tab-servo idea. I am not in the air yet but do folks need to be adjusting the aileron trim that much during flight to compensate for fuel burn ect?
 
Put me in the "aileron trim" not required catagory.

The controls are so light on the RV it's just not necessary IMO. I guess it would be nice if you like to fly around with one fuel tank empty and the other full but other than that it seems like more "stuff" that you reallty don't need. I originally installed the manual mechanism when I built the plane but wanted to do all the flight testing without it, 9 years later I've never felt the need to install it. No problem ever with the AP.
 
aileron trim

I installed mine per Vans plans. I use it often and it works well. It seems that I have to use it more at higher speeds because the left wing gets heavy. I never notice the wing heviness at anything below160 knots, but above that the left wing needs attention even if the fuel load is equal in both wings. I must be a little "out of rig".
 
Here's another possibility for you. Like Mike Seager, I put trim tabs on all three axis of my RV-6. I realize this isn't for everybody but I must say that I love this mod! Especially now that I have an auto-trim autopilot. I can look out on the left wing now and watch the autopilot slowly feed in trim as I burn fuel. When it gets a little too out of trail, it's time to switch tanks.

I designed my rudder and aileron trim on the same principle as Van's design for the elevator. Yes, it's a little more work, but if you enjoy this kind of detail it really is a lot of fun putting it together and having it work right!







Just for reference, with one tank full and one empty, it takes about 1/2 deflection of the trim tab to keep it trimmed.
 
You must log in or register to reply here.
Back
Top