[TShort]

Couple of questions as I get back into the floor of the QB fuse:

1. I laid out and drilled the holes through the F-445 flap blocks, everything looked great and in position, but I am just barely off on the edge distance for the right side hole through F-815C:

Thoughts? Anyone had a similar problem? Gonna email Vans on this one.

2. The QB fuse floors are not level. There is about 3/16" difference between the F-815C and the other subfloor structures (sorry the image is rotated):

This leads to bending of the F-830PP floor when installed and the flap blocks are tightened. Not sure if I should make spacers, or ... ? Anyone experienced this?

Thanks in advance.

 

[nzrv8]

I had the same issue with the flap bearing block holes into the F-815 support, Van's told me that it was ok as the nut plate underneath/floor panel above provides the strength so edge distance was less of a concern.

I can't recall having the other issue regarding floor heights, sorry.

Hugh

 

[scsmith]

floor level and edge distance

I built the older non-match-drilled fuselage, so not directly comparable, but I don't think you should have the floor mounting surfaces out of plane like that.

But here is a chance to fix two problems at once (kill two birds with one shot).

I made my floors removable, like many do. I put a nut plate on every-other hole for the floor mounts, no need to do every one. But two areas need special treatment, and this is one of them. You want to be able to remove the floor without removing the flap drive tube and mounting blocks, so you need a "shelf" around the blocks to support the floor skin. In your case, you can make a shim that sits on top of the longeron, adds some thickness for the height mis-match, adds an effective doubler for the marginal edge clearance on that hole, and make it wider in the area around the block so that it will support the floor skin in that area where you notch the floor skin to fit around the block.

If you make it 5/8" wider than the longeron for the last 4 inches or so, it will provide the shelf.

However, it may also be worth getting to the botom of the mystery of why that longeron is so low compared to the seat rib.

 

[rwagner24]

I'd like to know how you fixed the floor issue. I have the exact same issue. If I tighten my flap blocks the floor bows and touches the underside of the flap tube.

 

[TShort]

Unfortunately, I've been working on other projects in the shop and haven't been working on the -8.

I need to contact Van's about this, but have not had time to do so. If I find something out I'll relay it here - let me know if you find a fix.

Thanks
Thomas

 

[aviationone]

floor level and edge distance

If you modify the Flap Bearing Block (F-445) Per DWG 77 then when you install them on the Flap Torque tube gently pull them Outboard before drilling and you should be able to get just enough ED.

Below is L/H side.

Below is R/H side.

 

[Blain]

I worked on mine this weekend. What I see is the longeron is attached to the skin (or vice-versa) where it begins the roll to the bottom or another way of describing is that the sides are not parallel that low on the fuse. So the top of the longerons have the same angle up as the sides go in.

I considered trying to massage the last 8 or 10" to get level. Would correct what might be a bind in the flap weldment and puting the bow in the floor.

 

[RV8Squaz]

Steve has the right idea. I also made my floors removable and cut out a rectangle in the floor panel to clear the flap block. You could easily shim the longeron. I wish I would have gone one step further and cut the floors all the way across just forward of the torque tube. Even with the floors removable, it is difficult to wedge the panels under the torque tube.

If you decide to make your floors removable, I would make it so that the individual panels don't overlap each other . Make them so they butt each other with a little shelf and nut plates attached to one edge. That way you can remove one panel only without having to remove them all.

Jerry Esquenazi
RV-8 N84JE

I built the older non-match-drilled fuselage, so not directly comparable, but I don't think you should have the floor mounting surfaces out of plane like that.

But here is a chance to fix two problems at once (kill two birds with one shot).

I made my floors removable, like many do. I put a nut plate on every-other hole for the floor mounts, no need to do every one. But two areas need special treatment, and this is one of them. You want to be able to remove the floor without removing the flap drive tube and mounting blocks, so you need a "shelf" around the blocks to support the floor skin. In your case, you can make a shim that sits on top of the longeron, adds some thickness for the height mis-match, adds an effective doubler for the marginal edge clearance on that hole, and make it wider in the area around the block so that it will support the floor skin in that area where you notch the floor skin to fit around the block.

If you make it 5/8" wider than the longeron for the last 4 inches or so, it will provide the shelf.

However, it may also be worth getting to the botom of the mystery of why that longeron is so low compared to the seat rib.

 

[SHIPCHIEF]

I would like to present the other thought process:
Make the lightest minimum repair and pop rivet your floors down according to the plans.
Later, if you need to get under the floors, it's no big deal to lift the flap bellcrank and drill out pop rivets. Those LP4-3 rivets are cheap and effective.
Now that I'm flying, I wish I had made that first flight sooner.
I would advise reducing the mods right now. Git-er Done! you can add mods during condition inspections in the coming years on an as needed basis.
I talked to Andy Karmy last week, he's a local repeat offender who is posting his progress on this forum. He defines success in building, and is going simple and minimal on his RV-8.