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Aileron Trim Spring Installation

TangoUniform

I'm New Here
I’m attempting to install the OP-38 Aileron Trim System and am struggling with getting the two bias springs connected to both the right aileron torque tube and the trim servo operating arm. I’ve double checked the dimensions between the spring attach tabs (6” either side of the center position) and they’re correct. It requires a seemingly unreasonable amount of force to extend the springs; I seriously wonder if I’ll rip the attach taps off the torque tube. And then good luck trying to connect the second spring to the actuator arm.

Has anyone else struggled with this? Have I overlooked something? Any tips on how to get the springs connected? Any suggestions or guidance would be much appreciated.

TU
 
Yep. Pull hard to engage the springs. With the wings on, On my back, I stuck a foot in one of the access holes to stabilize and pulled way harder than I thought reasonable.
 
I used a “spring puller tool” for a trampoline my kids had when younger. I knew it would come in handy some day. Worked pretty well.
 
safety wire...

use a piece of safety wire to stretch the springs together, install in bell crank, clip safety wire...
 
use a piece of safety wire to stretch the springs together, install in bell crank, clip safety wire...
I needed this information a couple months ago. Great idea. I will say that the springs should not be installed within two weeks prior to any hand modeling gigs, as the little nicks and scrapes all over your hands are probably unavoidable no matter how you stretch the springs.
 
BTW there is a bit of offset to the springs. If you mount them the wrong way they will rub against the pushrod.

My springs came with some of the loops being almost fully closed so getting them on the trim motor arm is not an option as is. I asked Van's my options on trimming and was told the red or yellow lines would be OK, this should make mounting a bit easier also.
 

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I was dreading the spring install from other folks stories. Here's what I came up with. I used an old shoe lace to pull the springs together. First stretch a spring out a bit so you can thread the lace/string/paracord through the coils of the spring a few loops back from the hook part. See picture. Then do the same to the opposite spring. Have a helper pull the string ends in opposite directions to pull the springs together.

Since the pulling is being done on the main spring the ends can easily be maneuvered into position on the trim arm.

I used a modified tab that's about 1/8th inch longer to ensure clearance on the springs from the pushrod

5 min job. Easy peasy.
 

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I used this same method except used a long cable tie instead of the shoelace.

I was dreading the spring install from other folks stories. Here's what I came up with. I used an old shoe lace to pull the springs together. First stretch a spring out a bit so you can thread the lace/string/paracord through the coils of the spring a few loops back from the hook part. See picture. Then do the same to the opposite spring. Have a helper pull the string ends in opposite directions to pull the springs together.

Since the pulling is being done on the main spring the ends can easily be maneuvered into position on the trim arm.

I used a modified tab that's about 1/8th inch longer to ensure clearance on the springs from the pushrod

5 min job. Easy peasy.
 
Aileron Trim Springs

Can you guys tell me where you bought these springs??

I've been looking for the proper springs forever and they are either too soft or too strong for my aileron trim system.

Is there a specific strenght or force required for an standard electric aileron trim??

Thanks

Bruno
 
Springs are VA-158 Aileron trim spring

search term is VA-158
 

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I used this same method except used a long cable tie instead of the shoelace.

That's what I did, too - used a zip tie to pull them together at the same time.

The first try, I used needlenose pliers and ended up bending one of the springs really badly. Don't do that.

I used the zip tie method on my replacement spring and that worked really well.
 
Spring Spreader

Old Indian trick......

Place quarters between spring sections. Spring will grow..
Attach springs, remove quarters...or just run trim motor quarters will fall out...

Joe in Arizona
 
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