Removeable floor

prkaye · #1 11-15-2007, 08:10 AM

I'm going to make all my floors removeable (mainly because this avoids the need for another "pre-cover inspection" as required by Canadian rules). Next week I'm going to be assembling the center fuselage, with all those floor ribs. Question, do I need to put all the nutplates on the floor ribs now, or can that be done later, after it's assembled and I'm ready to put the floors in?

LettersFromFlyoverCountry · #2 11-15-2007, 08:22 AM

You can. But why would you want to? I did it AFTER the ribs were installed and the one problem I had was getting at the underside of the rib to debur. Minor thing, yes, but still frustrating.

Rick6a · #3 11-15-2007, 09:15 AM

Quote:

Originally Posted by prkaye

I'm going to make all my floors removeable (mainly because this avoids the need for another "pre-cover inspection" as required by Canadian rules). Next week I'm going to be assembling the center fuselage, with all those floor ribs. Question, do I need to put all the nutplates on the floor ribs now, or can that be done later, after it's assembled and I'm ready to put the floors in?

Phil,

You can do it either way you want. I think you will find, however, that in the long run it will be a much easier and faster job to go ahead and install the nutplates on the individual ribs now while you are seated on a stool at the workbench as opposed to waiting until after the ribs are installed and then finding that access and installation convenience is significantly diminished by comparison.

chaskuss · #4 11-15-2007, 09:57 AM

Phil,
The fastest way is to IGNORE the instruction to rivet the floor ribs to the rear spar now. Leave everything clecoed. Once you have all your skins drilled and clecoed on, fit the floor skins with the fuselage upside down in the jig (or sawhorses). Once the floor skins are drilled and clecoed on, take EVERYTHING apart for deburring and dimpling.
Are you going to use #6 or #8 machine screws to hold down the floors??? The rest of my advice will vary depending on what size screws you use.
Regardless of screw size, you can drill and fit the nutplates to the floor ribs while the ribs are out and apart. After you drill, deburr, dimple, (Alodine if desired) & prime you floor ribs, you can install "most" of the nutplates before reassembly. This will take some head scratching prior to disassembly, because some of the nutplates must be left off for now. Premature installation will impede or prevent easy riveting of the ribs/skins during reassembly.
Charlie Kuss

prkaye · #5 11-15-2007, 10:02 AM

Quote:

Are you going to use #6 or #8 machine screws to hold down the floors???

Was thinking #6 to save weight, but maybe #8 would be easier to work with, and the weight difference would be negligable? Recommendations?

vlittle · #6 11-15-2007, 11:05 AM

Hey Phil. Why not just make a couple of access panels that are screwed down to the floor?

I put my strobe PSU underneath one, and the other is just for inspections. That way it's a few platenuts rather than dozens. Your MD-RA inspector can view your internal handiwork with an inspection mirror.

Platenuts and screws are unneeded weight if you never plan on removing the floor. A couple of well-designed panels will give you all of the access you need. When I added a flap limit switch, I drilled out some rib tooling holes for snap bushings using my right angle drill through one of the panels. No problem.

Vern

prkaye · #7 11-20-2007, 08:09 PM

For putting the nutplates on the floor ribs (to make the removeable floor)... there's one spot where the nutplate won't fit... one side of the nutplate overhangs the edge of the flange. What did you guys do about this?
Photo attached...

Kevin Horton · #8 11-20-2007, 08:31 PM

Quote:

Originally Posted by prkaye

For putting the nutplates on the floor ribs (to make the removeable floor)... there's one spot where the nutplate won't fit... one side of the nutplate overhangs the edge of the flange. What did you guys do about this?

Phil - I bought some one leg dimpled nutplates to solve that exact problem. I think I have a few left over if you need them. I'm on the road right now - I should be back on Thursday.

chaskuss · #9 11-21-2007, 03:50 AM

Quote:

Originally Posted by prkaye

For putting the nutplates on the floor ribs (to make the removeable floor)... there's one spot where the nutplate won't fit... one side of the nutplate overhangs the edge of the flange. What did you guys do about this?
Photo attached...

Phil
Use a "one leg" nutplate for these areas. I had to use several of them. Are you planning on pan head screws or flat head screws for retaining the floor skins?
Per your earlier question, I asked the same thing of my local RV guru, Jody Edwards. Jody said that his experience (25 + years as an A&P/IA) he found that #4 & #6 screws sometimes would break when you attempted to remove them. He said this didn't happen with #8 or larger screws. I used #8 flush screws on all my flooring. In retrospect, flush screws offer no advantage along the left and right outer edges of the floor skins. These areas will never have seat cushions on them and your feet will never be placed in those areas.
I can send you photos of my floor skins with the nutplates attached if you desire. What model RV are you building?
Charlie Kuss

Rick6a · #10 11-21-2007, 04:25 AM

Quote:

......there's one spot where the nutplate won't fit... one side of the nutplate overhangs the edge of the flange. What did you guys do about this?

Nutplates come in many, many variations. In this situation, use a single leg nutplate also known in some circles as a "one lug anchor nut."

http://www.aircraftspruce.com/catalo...anchornuts.php

I used #6 and #8 truss type screws because they are easier to install and service. Besides, when the rear seat is in place, the only exposed screws are around the perimeter of the floor anyway.