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Trying to get my head wrapped around the upcoming installation of the tailpost assembly. As those of you who have completed your tailcones already know, there seems to be a nightmare of components that all need to come together at the same time. I've got most everything placed, aligned, and drilled. I've stared at the channel and Y-fitting cluster long enough to need the next size stronger glasses. Is there no way to install the bolted together parts after the channel is riveted to the skins to eliminate the hastle of interference of the doubler/rivets? My wife has small hands and it "looks" like it should be possible.
Can't find it now, but I thought I saw an EAA chapter build that used solid rivets to hold the channel on, which would mean a bucking bar or squeezer must have been used and no Y-fitting could have been in place. I'm not inclined to "bend" the flanges to make room for a rivet if I don't have to, and removing enough material from the doubler to clear a rivet seems counter-productive. Anybody have any insight?
Thanks from Dazed and Confused @ Area 51%

Randy,
I was having trouble setting rivets through the skin into the channel until somebody pointed out the part on the plans that call for the skins to be flared out. That does work.

Fritz over in Chapter 555 had posted that they used solid rivets to fasten the channel then bolted up the thick stuff. Ryan had to replace his Y fitting and he did it after riveting. He is 6'3" and managed to unbolt the assembly. It can be done apparently.

I was happy with bolting it up first, bending the skins, and riveting after. Bolting while assembled seemed hard to me.

Yes, it's possible to bolt the doublers after riveting the rudder hinge, however as Bryan said, you'll need to bend outwards the skin a bit. When you do this, you'll realize that the rudder stop plate will keep you from bending the skin at the bottom of the post, but the rivets there don't interfere with the doubler (it doesn't go down that far.) yes, this means you'll have a slight "twist" in the rudder piano hinge (flared out on the top 2/3, straight on the bottom 1/3), but it's not a problem (wasn't for me at least) and this is what Sonex says to do.

As proof of concept, I actually had to remove and replace my entire tail post/doubler stack later in my build. it is indeed possible to access all of the bolts even after the aft fuse is all riveted up (minus the floor), it's just a PITA.

One more note that I didn't catch until later... the piano hinge for the rudder is a different material than the rest of the control surfaces, it's the "closed loop" type. Double-check the material part number on the plans.

Hi Area51 Guy,

Before you do anything radical concerning riveting in your tail post, let me tell you I had absolutly no problem riveting mine in. The mistake I made was to bolt the Y in with the bolt heads on the inside pointing aft. The nuts and washers are easier to install this way, but don't do it. The threaded end protrudes farther out than the bolt heads, and interfere with rudder movement. So I had to take them out and reinstall them with the threads pointing forward. Nuts and washers are so much harder to install, but you must do it this way. I would include photo of my tail post if I knew how to post one. If you're interested I can email photos to you. My email address is robieal2011@att.net

AL Roberts

To keep things in perspective as you cuss your way through finishing up the tail cone, observe a moment of silence for those of us who had just finished up closing up the tail when the Service Bulletin came out to install the doublers. There's still a lot of my DNA in the tail from that. But it can be done if you have hands the size of a toddler.

fastj22 wrote:a moment of silence for those of us who had just finished up closing up the tail when the Service Bulletin came out to install the doublers.

..... observed. I was swearing up a storm for/during having to replace my tail post, but what you guys faced was even worse with the floor already in place.

I had to retro fit the doubler on mine. I had my daughter give me a "little" hand getting the washers and nut on the bolts. I haven't riveted the aft floor in place yet so that helped also as previously noted. I did bevel the doubler sides a bit to match the taper of the tail and squeezed the rivet tails with a pair of vise grips which also helped provide more clearance. By doing those mods I didn't have to bend the skins/channel outward at all

Rynoth wrote:One more note that I didn't catch until later... the piano hinge for the rudder is a different material than the rest of the control surfaces, it's the "closed loop" type. Double-check the material part number on the plans.

Uh oh...

Yea.. my hinges are still the open loops. I'm going to monitor how they wear and replace on condition. Won't be any more difficult to replace later than it is now. I imagine they are subject to more forces than the other flight controls due to the tailwheel/ground contact. Also the rudder cables alays pulling on the rudder.

Rynoth wrote:One more note that I didn't catch until later... the piano hinge for the rudder is a different material than the rest of the control surfaces, it's the "closed loop" type. Double-check the material part number on the plans.

After reading this I checked my plans and the sonex site for revisions. The Sonex plans spec MS20257P3 open loop for the rudder hinge. There are no drawing revisions for this.

Using the extruded hinge on the rudder must be a Waiex specific thing.

Steve
Sonex 892
VH-ZSX 195hrs