Install rudder rod end bearings before riveting on the skin?

Hey all, I am getting pretty close to riveting up the control surfaces on my tail kit. Tonight, I was riveting on the rudder skins in preparation for final riveting, and I was contemplating if I should go ahead and install the rod end bearings that is used to mount the rudder and elevators to the stabilizers.

After looking over the plans, I noticed this:



Take a look where the red circle is. The plans give the dimensions from the inside flat of the spar, to the center of the hole on the rod end bearing as 51/64". Now, if I rivet on the skins, I won't be able to accurately measure this distance.

Do I need to go ahead and screw in the rod end bearings before I cleco on the skin so I can get that exact measurement? Or, is is safe to leave those bearings out until I get ready to hang the control surfaces later on in the build? If thats the case, how do you get the right distance that they need to be threaded at that point?

My thoughts

I thought about doing this myself. But after i got done, I realize it was best to follow the build manual. I set my dimensions by subtracting the thickness of the plate from the dimension I measure.

The plans tells us to install the rod end bearings in the elevators at some point, but I don't see anything that tells us to install the rod end bearings in the rudder.

I wonder if I go ahead and install them with the skin off, will they get in the way when the time comes to roll that leading edge?

On the 8, the plans state that dimension is from the forward face of the spar web. I would check that 'note 1'

Leave them out for now if you haven't rolled the leading edge yet. You will need to get a piece of pipe up there and be able to grab it with vice grip pliers in the gaps where the bearings go. The rod end bearings will be in the way.
Tom.

Wunderon said:

On the 8, the plans state that dimension is from the forward face of the spar web. I would check that 'note 1'

Click to expand...

On the 7 I think that's right for the rudder. The elevator however is from the outer web doubler (which is a lot easier to measure). I just did the math on the rudder to account for the thickness of 2 doublets and the web and measured from the outside.

As mentioned wait until after you roll. And making a pvc tool to screw them in per some of the build logs is the way to go IMHO.

Read SB 14-02-05

There have been some cracks found - you can find better pictures on VAF. There is some "discussion" about the exact mechanism, and whether a loose jam nut is the root cause.

Regardless if you do this SB or not (now), it has some measurements from the outside of the spar to the center of the eyes. You may want to source a rod to fit in the holes to align and serve as a measuring point for your dial caliper.

Keep in mind that you can only adjust the position by 1/2 the tread pitch increments anyway, i.e. 1/2 turn. And YES make a tool. I used an old socket and slotted with a dremel. That huge nut plate is pretty tight.

Happy Building

It is very likely you will have to adjust one or two of the bearings when you are installing the rudder onto the VS. The dimensions given are a starting point that will get you very close. Not difficult to install the bearings after the rudder assembly is complete.

Service Bulletin

BillL said:

Regardless if you do this SB or not (now), it has some measurements from the outside of the spar to the center of the eyes. You may want to source a rod to fit in the holes to align and serve as a measuring point for your dial caliper.

Click to expand...

Interesting, didn't even know this SB existed. My plans (emp kit shipped 7/16) has the SB doublers in the build. I bet that's why the plans show measurements from the outer elevator doubler (revision), while the rudder shows from inside. Would make sense that elevator was redrawn with new dimensions while rudder is original. Wondered why when I was building- that cleared it up thx!