What's new
Van's Air Force

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

Aileron Bellcranks

Robert M

Robert M

Well Known Member
Hi gang!

I'm working on my spars. I have the Orndorff video for wing construction and it's for the RV-7/A. Other than a few minor points, the construction sequence should be about the same. Having said that, the video shows the assembly of the aileron bellcrank during the first stages of wing construction. The plans for the RV-9/A have you wait until right before you close the wings.

My question is, would it be prudent to go ahead and fabricate these parts or is it best to wait until later per the instructions?
 
Aileron Bellcrank

Having just finished the bellcranks in my 9, you could do it early in construction. I had to slightly enlarge the hole in the rear spar for the aileron pushrod due to the rivets on the end. Overall, it won't make a difference. You would have to modify the right wing bellcrank if installing a roll servo. The roll servo mounting bracket replaces one of the bellcrank brackets.
 
Aileron Pushrod Length Confirmation

I'm ready to fabricate my pushrods and wanted to confirm the lengths they are to be cut. I understand that the elevator pushrod plan specified length is questionable. Has anyone found a problem with the plan specified lengths for the big tube or the small tube?
 
Aileron Pushrod length

The big pushrod, cut as per the drawing.
The small aileron pushrod - I cut mine about 5/8". After installation, I think you can get by without cutting the small pushrod at all, or maybe 1/4" at most. Try it before cutting, and you will see what I mean.
 
Cut them per plan works fine. I also enlarged the aileron pushrod hole on rear wing spar to clear rivets on the small pushrod. After you assemble the aileron and the pushrod to the wing, make sure at all movement of the push rod, the pushrod will not catch the side of the hole. If rivets are not squeezed to the same length it is possible that at some position the pushrod may get stuck and some other position not. That was what happened to mine. Fortunately, I caught it during the assembly and not my first flight.

Ted
RV9A, #91048, O320D2A, FP, 127 hr since 8/16/2006
http://tc1234c.googlepages.com/
 
Grease?

Along the same lines, are we supposed to be greasing the tube/bellcrank, or running dry? Rick 90432 wings
 
hijakcking

Since the threads been jacked - I'll go with the flow.

The bolt in the brass tube for the bellcrank, according to the directions, gets a thin coat of your favorite grease type lubricant.
 
Sorry Robert

Robert M said:
Since the threads been jacked - I'll go with the flow.

The bolt in the brass tube for the bellcrank, according to the directions, gets a thin coat of your favorite grease type lubricant.
Click to expand...

My Bad :(

Ahem! Hey EVERYONE! The question is when is the best time to assemble the aileron bellcrank?

My -9 plans say to assemble the bellcrank and the pushrods right after completion of the flaps. It specifically says to wait until the ailerons and flaps are completed before doing so. I am at this stage right now. I have riveted the rod ends on the large tubes and will be welding the end rods on the small tubes this weekend. Then the plans have you install the aileron on the wing and align with the alignment piece you were to mark at the beginning of wing assembly.
 
smithhb said:
My Bad :(

Ahem! Hey EVERYONE! The question is when is the best time to assemble the aileron bellcrank?

My -9 plans say to assemble the bellcrank and the pushrods right after completion of the flaps. It specifically says to wait until the ailerons and flaps are completed before doing so. I am at this stage right now. I have riveted the rod ends on the large tubes and will be welding the end rods on the small tubes this weekend. Then the plans have you install the aileron on the wing and align with the alignment piece you were to mark at the beginning of wing assembly.
Click to expand...

smithhb, no problem. :) I hate I even said anything - I wasn't thinking. This forum is for the sharing of information and that's what we've been doing. My question got answered and MORE information surfaced - good information that I'm gonna need later. Nope, it was really my bad and I appreciate the input from everyone on this Forum.
 
cutting the big tube

I would wait on cutting them till you put the wings on, mine were too short per plans.. 3/8 would have felt better but I wanted my bearings screwed in
a little futher so I ordered new tubes and cones.. whats the rush to cut the
tubes ? I say wait till the wings are installed and you can get a really good
idea of how you want the bearings screwed in.. if your waiting for
the fuse kit then just do one end and wait on the other.. don't rush it..


Danny..
 
Too Short?

Danny,

I'm a little confused that your tubes were short. I have searched the archives of the RV List (s) as well as the Forum and found no mention that the plan lengths were short.... :eek:

I even called Vans and they confirmed the plans lengths were fine. However, they did say they were aware of some problems with the elevator pushrod length being too short.

Thanks for the heads up.
 
Lube What??

Robert M said:
Since the threads been jacked - I'll go with the flow.

The bolt in the brass tube for the bellcrank, according to the directions, gets a thin coat of your favorite grease type lubricant.
Click to expand...

Is the engineering for the bell crank different on the 9 than the 7? On the 7 the instructions indicate that you lube the OUTSIDE of the brass spacer, as the Bell Crank rotates on the Trapped brass bushing, that is: the bushing stays still (since it’s trapped/squeezed by the bolt) and the movement takes place between the outside of the bushing and the inside of the bell crank. Same as the Controll Stick
 
Last edited:
Some work OK and some are too short. There have been several posts advising to wait until the wings are trial fit before making the pushrods. I made the short ones twice because they were too short. Mine ended up about 1/2 inch longer than the plans and worked fine. There wasn't near enough thread engagement to suit me. One thing that confuses some is the the right bell-crank goes on the left wing and the left goes on the right. These are the same parts that fit the 7 but because of some differences in the wing construction it was necessary to reverse the two bell-cranks. That information came from Gus. You don't expect to assemble a part marked left on the right wing.
 
You must log in or register to reply here.
Back
Top