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The plans say don't rivet the stabilator tip until the ruddervator is installed, since the hinge pin is bent at both ends. Certainly seems way easier to bend the one end, then slide it from the top without the stabilator in the way. That's all fine, but I'm going to want to remove the ruddervator later when I need to disassemble the aircraft for painting after my 40 hour fly-off.

It's not riveted on yet, but I'm curious if anyone else has an idea on how to approach this. Do I just drill the rivets out later on? Should I consider nutplates and screws?

I put my tips on with nutplates. I was going to use aluminum rivets on the left one, but I got lazy as I didn't feel like doing the bondo and paint yet. The right one has my pitot tube mount.

Bryan Cotton wrote:I put my tips on with nutplates. I was going to use aluminum rivets on the left one....

For what it's worth, I received guidance in email from Sonex that the ruddervator tips are structural and should be fixed with stainless rivets. The main wing wingtips are OK with aluminum rivets since non-structural. Your nutplates might be OK, but they specifically told me not to use aluminum rivets for tail tips.

I did rivet my tips after installing the pin, and would have to drill them out if I wanted to remove the ruddervator. If wanting to remove them later, might ask Sonex if alternative fasteners are acceptable (i.e. nutplates/screws.)

I'm contemplating this same issue now. Has anyone considered just inserting the piano hinge pin from the bottom? There's nothing to block it, and you could secure the pin by safety wiring it or using a tiny cotter pin like the aileron hinge pin.

I just put the pin in backwards and there's nothing in the way, and it seems like you could just replace the top two bolts on the tail post with drilled head bolts, then you'd have a perfect thing to safety wire the pin to.

Any reason not to do this? I can't imagine there's any risk of the pin coming out if it's properly safety wired, and that would make the ruddervators easily removable without messing with the stabilator tips.

Attached is a picture of what I'm talking about.

ALSO, I was looking at some pictures I took of the factory B-model at Airventure, and I noticed it looks like they have a cotter pin through the last link of their piano hinges. I haven't asked since it's the weekend, but I wonder if this issue is why they used those cotter pins.

Spaceman wrote:I'm contemplating this same issue now. Has anyone considered just inserting the piano hinge pin from the bottom? There's nothing to block it, and you could secure the pin by safety wiring it or using a tiny cotter pin like the aileron hinge pin.

I just put the pin in backwards and there's nothing in the way, and it seems like you could just replace the top two bolts on the tail post with drilled head bolts, then you'd have a perfect thing to safety wire the pin to.

Any reason not to do this? I can't imagine there's any risk of the pin coming out if it's properly safety wired, and that would make the ruddervators easily removable without messing with the stabilator tips.

Attached is a picture of what I'm talking about.

Sounds like a plan to me. Just last week I removed the tail, ailerons and flaps from my sonex to paint it, so its fresh in the memory. First time they'd been removed in 10 years.
If I were building again I'd be leaving a bent pit of pin on one end of each hinge like in you first photo. Cotter pins are simple but if you want to get the pin out it is pain with nothing to grip to get it moving. Much easier to remove hinge pins by pulling rather than making special tools to punch it out from a very tight space.

Sounds good, I think this will actually work pretty well. I talked to Kerry and he said to go for it as long as the pin is secured so it won't work its way out, and nothing obstructs the movement of anything. Here's a better picture of what I'm thinking. I ordered new bolts with a drilled head, and I think I'll bend the end of each pin more into a hook shape, then I think with some safety wire there's no way it'll go anywhere.