Cable Cutting Through

[BRS]

I've been watching this right rudder cable slowly cut throught the skin. I've not yet decided how I want to deal with this. Have others had this issue?

I'm not the builder, just the fixer. The installation looks suspect but I've not yet tried to find the area in the plans. Do you see any obvious departures from how it should be?

Thank You!

[sonex892.]

I dont know what is causing the cable to saw away at the penetration but guess its possibly a misaligned slot or incorrect rear cable guide fairlead position.

I noticed in your photo there is some non standard stuff.
No springs at the rudder pedals. Its obviously by the way the cable is sagging allowing the cable to touch the bottom of the slot until tension is applied.
Nicopress, thimbles and straps instead of fork ends securing the cables to the rudder horn?. Maybe not an issue but not per plans.

Do you have a set of plans to refer to?
Steve

[Bryan Cotton]

Yikes! I did mine to the plans. On my Waiex my cable exits were good, but I had to open up the ruddervator pushrod slots. Any contact when it comes to controls is too much. We used to do safety and clearance checks at Sikorsky during the build of an experimental aircraft and I carried that mentality over.

[BRS]

Thanks Steve & Bryan for the reply.

Yes I do have a set of plans and now will dig them out. I know, should have done that first. I suspected pedal springs might be something that some folks do but really, that does not seem to be a safety of flight thing considering my feet don't (but might one day) leave the pedals. This cable alignment though needs to be remidied. Like I said "not the builder but the fixer" and I've got more fix'n to do. So it seems.

I appreciate being able to bounce things like this off the forum group.

-brs

[GordonTurner]

Hi Brock

As others have said, this installation is non-standard. I would encourage you to study the section of the plans, which isn’t always the easiest to understand. I would make a list of parts from the plans, and order all new components from Sonex. Flight controls really aren’t the place to screw around. That said, the home-brewed installation you have may in fact be satisfactory, but I would suggest needs a much more detailed review than we can provide on an Internet forum.

Hate to say it, but I also think a very thorough review of the rest of your flight control system would be advised, plans in hand.

Good luck, Gordon

[Area 51%]

My money is on the exit slot being in the wrong location. Page F26 shows the correct locations. The aft end of the right-hand slot should only be 9in from the rear of the fuselage. The left side slot is 15in from the back.
I'm guessing the original builder assumed the sides were symmetrical.

I've seen more than one Sonex with a mislocated slot with a patch over it.

[Bryan Cotton]

I also deleted my rudder return springs. Schweizer Aircraft also did not believe they were important.

Sounds like Randy has the cause figured out! I'd forgotten that detail.

[BRS]

My money is on the exit slot being in the wrong location. Page F26 shows the correct locations. The aft end of the right-hand slot should only be 9in from the rear of the fuselage. The left side slot is 15in from the back.
I'm guessing the original builder assumed the sides were symmetrical.....

This was my suspicion all along.

BTW - The entire control system has been carefully inspected. Not for conformity to experemental sonex plans but as a matter of good & reasonable practices. Good thing the cable is steel and the skin aluminum and not the other way around ;-)

[Murray Parr]

My Waiex B model has a similar issue, the pax side cable is so close to rubbing on the exit that I wrapped it in teflon tape and applied heat shink over that to make sure it doesn't start wearing through. I double checked all the dimentions for the mixer controls and fairleads and all were exactly as per plans. I never saw a dimension for each exit so I will investigate that possibilty for mine. The pilot side has plenty of clearance

[Bryan Cotton]

It's a lot safer to open up the slot.