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Flap rod installation

tdk

Active Member
Is there any reason I should not reverse the bolts holding the upper flap rod bearing to the flap bar weldment?

The plans show the bolt head on the outboard side, but I don't have enough room to install the bolt through the bearing. If I unbolt the weldment and install the upper bearing, I am unable to align and insert the stud on the lower bearing into the flap.

Reversing the bolt allows much easier adjustment of the flap rod length, and there seems to be plenty of clearance to the fuselage side skin. I suppose the nut could more easily hang up on the rudder cable, but I plan to make a small bracket on the baggage cover to keep the two separate.
 
If I recall, mine is installed as you have requested with the nut outboard. I do also have a J bracket on the side panel to keep the rudder cable in place. Mine is a 6A.

When you make your J brackets, bend enough tension on the leg so it will definitely contact the side skin with a little pressure.
 
Bolt head inboard

I installed mine with the bolt heads inboard. I remove the bolts every conditional inspection and release the flaps to inspect the flap hinge and rear spar. Didn't see a good reason to jump through extra steps to remove the nylon blocks/bolts just to get the bolt out or untreading the rodend if the bolts were installed per plans.
 
There was one guy here that had his rudder cable snagged by this bolt, the nuts go inward, unless you capture the cable like mentioned above. yes, I too had to remove the weldment to install correctly :eek:
 
I installed mine with the nut inboard too. I want the record to show that I did it in protest. It seems to me if I have to do work on one flap I run the risk of doing more harm than good taking the entire weldment out.
 
Flap rod - a better solution

Gentlemen,

On my RV7A, Papa Mike, I looked at that and decided I had a better solution. On the upper rod end bearing I used a reverse thread. The bearing is the same price as the standard thread but now to adjust the flaps, I loosen the lock nuts on both ends and turn the rod, just like a turn buckle. May I suggest that you convert to that design.

Ruley
 
If it can it will?......with a RH thread on both ends and installed with enough thread in the rod ends, the unit will bottom out on one end preventing the assembly from coming apart, however, with one LH and one RH thread it could come apart IF both lock nuts came loose, highly unlikely but......:rolleyes:
 
...On the upper rod end bearing I used a reverse thread...

I do that in exactly one place on the HP-24 kit sailplane. Well, two places, one in each wing. Some notes and commentary:

* The place where I use the turnbuckle arrangement is to set the downlock travel of the airbrake drive arm; that's the only place in the whole glider where I need adjustment down to a couple thousandths of an inch. Everywhere else, a half-turn of a 1/4-28 thread (1/56" or 0.018") is plenty of resolution.

* As others point out, the turnbuckle arrangement can become completely disconnected if both jam nuts loosen. The possibility is pretty low, but it is a thing to be concerned about. Double-righties completely protects against that.

* Where I do use left-handed rod ends and nuts, I am careful to mark both as unique--we buy color-plated nuts, and turn a marking ring into the rod. Even so, I figure it is only a matter of time before someone strips one out trying to loosen it counterclockwise.

* Stocking the lefty nuts and rod ends has become an inventory hassle, and I can't blame Vans for having no truck with it. Even with the rods and nuts marked, we've had a couple other things in the shop ruined when someone tried to use the lefty parts or tools on them.

--Bob K.
 
The nuts are on the outside near the skin in my plane. I couldn't fit the bolt in from the outside. I was worried about the rudder cable getting snagged so I enclosed the cable in 1/2" cpvc pipe from in front of the spar, through the cabin and past the flaps section. I probably added 1/2 lb, but the cable can never get squished by the seat or on the flaps bolt. Worth it for me.
 
Thanks

Thanks for all the thoughts and suggestions. I put the nuts outboard, and added a guide to keep the rudder cable separated from the flap rod.

4qod29.jpg
 
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