SonexBuilders.net

Amazing how small things stall the project. The rudder springs are doing my head in. What length spring did people use for the standard rudder pedal position. How did you attach the spring to the bulkhead?
Thanks

I am building a Sonex, the rudder spring lengths and bend dimensions for each end are in the DWG's if I remember correctly. There should be a hole in the angles on each side of the firewall that the springs attach to. Although because of the angle of the springs from the firewall to the rudder pedals they are not capable of actually centering the rudder very well.

Terry

ajscott, (A.J.?)
For my rudder springs I used springs I bought at Lowes aircraft supply. The ones supplied in the kit were, in my opinion, too stiff and when cut and bent just didn't feel
correct. It took a lot of trial and error to get the right "feel". To measure the length I pushed the rudder pedal toward the firewall, measured that length, and subtracted a small amount to allow the spring to remain in slight
tension when that pedal is forward. Duplicated on the other side. They are mounted to the outer vertical firewall angles under one of the nuts that holds all the angles and
pieces in the lower corners of the firewall together. If I had it to do again, I would make a small bracket in the mounting area that would allow the springs to be changed
more easily if you decided the tension was not enough or too strong for tour liking.
One thing is to BE SURE the springs you choose do not "stack up" under the pedal when that pedal is full forward. The springs are there mainly to keep slight tension on
the rudder cables.
Keep a close eye on the plans AND the revision log. Don't hesitate to use Sonex (Kerry) and their tech line. (e-mail)
Careful building and safe flying! Can't wait for mine to fly. I turn 66 today and the clock is running.
Frank
ONEX090

Is there a "down side" to not using the springs? My Sonex that I recently sold hasn't had springs for about 6 years. As far as I can tell the only thing the springs do is keep slack out of the rudder cables when the pilot doesn't have his feet on the pedals. Me...I fly with my feet on the pedals. On the ground I'm not concerned with slack in the cables.

Hi ya'll,

Alas - I see the instructions on bending the springs etc... However, on the drawing I don't see a particular position on the angle to drill the little 1/8" hole for the spring to attach to. Does anyone have a record of where they drilled their hole?

The reason I ask is that I'm not planning on installing springs at this time. On my RV I didn't have springs and I gather they aren't really needed on the Sonex either. However, I figured I'd put the hole in now so that I don't have to try and drill around up there someday in the future if I wanna add springs after the plane is flying...

Kevin

kevinh wrote:Hi ya'll,
Alas - I see the instructions on bending the springs etc... However, on the drawing I don't see a particular position on the angle to drill the little 1/8" hole for the spring to attach to. Does anyone have a record of where they drilled their hole?
Kevin

SNX-F14-02 on the Sonex plans. 166.5mm down from the absolute top of part and 3.2mm from edge to centre of hole. Or if you like imperial 6-9/16" and 1/8" with 1/8" dia hole.

sonex892. wrote:

kevinh wrote:Hi ya'll,
Alas - I see the instructions on bending the springs etc... However, on the drawing I don't see a particular position on the angle to drill the little 1/8" hole for the spring to attach to. Does anyone have a record of where they drilled their hole?
Kevin

SNX-F14-02 on the Sonex plans. 166.5mm down from the absolute top of part and 3.2mm from edge to centre of hole. Or if you like imperial 6-9/16" and 1/8" with 1/8" dia hole.

Awesome - thank you so much! I must have missed that. Super cool!

FWIW: On my Onex, I used 5/8 x 3-1/4 x .072 Hillman Springs #543008 from Lowe's. They were the right length for my rudder pedals with minimum bending needed for the ends.

I installed the springs on my Sonex, then after 2 flights took them off to try it without them because there was just something I didn't care for with the feel of the springs.

3 years later and the springs are still sitting on my shelf never having been reinstalled. I haven't noticed any odd behaviors or tendencies without them.

Never installed them on mine. The plane flies perfectly fine without them. They only take up the rudder cable slack. As soon as you put your toes on the pedals it does the same thing.

Keith
#554