Joining of centre bottom skins

[Jonnyb]

Afternoon all,

Am working through the Seat Rib Assembly (DWG65) and am just wondering when people joined the centre bottom skins? (F-826-1 and F-827-1)

The instructions say this:
"Dimple Countersink all #40 holes in the F-826-1 Right Center Bottom Skin and the F-827-1 Left Center Bottom Skin, which are common with holes in the Seat Rib Assembly. NOTE: Do not dimple countersink the fwd and aft most rows of holes that are not common with holes in any of the seat ribs (See “F-826-1 & F-827- 1 Center Bottom Skins”, DWG 65)." (My Bold)

The row of rivets that join the 2 skins aren't in common with the seat rid assembly in that they don't join to any seat ribs. So according to those instructions they should be left untouched. But I can't see, looking forward in the plans, where these 2 skins are joined.

It's the row of rivets circled in red on the attached plan. (DWG65)

Can someone point me in the direction of when this is done? or is it done now?

 

[Mikeyb]

I think it refers to the two rows of holes that attach the bulkhead and aft bottom skin that you dimple when those parts are added.

 

[Jonnyb]

I think it refers to the two rows of holes that attach the bulkhead and aft bottom skin that you dimple when those parts are added.

Thanks Mikey,
can I ask when you joined your skins? was that at this point when assembling the seat ribs?

 

[Mikeyb]

It’s probably been too long for me to be useful. I remember being puzzled by this but can’t remember the details.

 

[PhatRV]

This was the extend that I riveted this aft floor section before assembling the fuselage canoe section. I dimpled the center section but left the last three hole unriveted. I didn't have trouble with the assembly of the fuselage canoe with this.

 

[N804RV]

most of the rivets you circled in red in your picture, its safe to go ahead and dimple. If you don't do it before you start riveting skins to seat ribs, it'll be harder to do it later.

I just started clecoing parts together and reading that section over and over till it made sense. I marked each hole on the skin by what length rivet it got. The holes without a mark didn't get riveted.

There's specific one that don't get riveted till later because other parts are joined there. If you cleco it all together and start adding bulkheads, it'll make more sense.

Here's some pictures of my bottome center section with seat ribs. Hope this helps.

 

[Jonnyb]

Cheers guys, that helps.