M

MarkSchmitz

Member
I know a number of builders have opted for nutplates in place of pulled rivets to make the floors (F-830PP, F-831PP, F-834PP) in the fuselage removable. I need input on whether to go with #6 or #8 plates/screws and whether or not to make them flush.

Thanks,

Mark
RV-8 Fuselage
 
I opted to split the forward section of the rear floors and make them removable. If you search the archives you can find a picture i posted. I also used #8 screws (pan head, not the ones suppled in the kit) in every other prepunched rivet hole. Did not counter sink because plan to use carpet on the floors. Also, if you turn the fulelage on its side, you can sit on a stool and install platenuts with out having to lean over the rail and bruse your armpits! If you can't find the picture, e-mail me and i'll send them to you directly.

[email protected]
 
I used #8 pan heads and used every hole. (I ended up making 7 removable floor panels, including the footwells.
Doing it again, I would use every other hole and use #6 pan head screws, but the #8's are fine and look great.
Flat head screws would be cool, but a lot more work.
 
#6 vs #8, pan head vs flush

I opted for #8 pan head screws when I did my -8 floors.

I wouldn't feel comfortable with #6 screws. You can snap a #6 screw a lot easier than a #8 if it gets bound up in the nutplate.

Dimpling the skins and then countersinking the ribs will add a lot more work.

Some of the areas are difficult to work in, espcially the corners & longeron area. Keep that in mind for countersinking.

Your call if you want to countersink, but I would stay away from using #6 screws on the floor.

Good luck.

-Mike Draper
RV-8 finish
 
Thank you for the replies! Based on the input and shared experiences, I'll be going with #8's, non-flush. I might try washer head screws (AN525) if they're lower profile than the pan head. I'll definitely take advantage of Tom's approach to making the floors easier to get in and out; my first fitting was a bit of a challenge...

Thanks again,

Mark
RV-8, Fuselage
 
MarkSchmitz said:
I know a number of builders have opted for nutplates in place of pulled rivets to make the floors (F-830PP, F-831PP, F-834PP) in the fuselage removable. I need input on whether to go with #6 or #8 plates/screws and whether or not to make them flush.

Thanks,

Mark
RV-8 Fuselage
Click to expand...

Mark,
Flush screws work best along the bulkhead and inner rib areas. Otherwise, the pan head screws will damage the bottom surfaces of your seat cushions and catch on your shoes. The outer rib areas can use standard pan head screws. Stick with #8 screws. #4 & #6 screws often break off in the nutplates. Using #8 screws will cut future maintenance Way down.
To eliminate having to remove the flap cross bar (Wd-806) or any flap rigging, I sheared the F-830 and F-831 skins into two pieces. This allows you to remove the rest of the flooring without removing any flap hardware.
On the bench, cleco these two skins together. Measure 7.5" forward from the aft edge of the skins. Draw a line across the skins at this point.
You will later cut the skins on this line. The aft end gets riveted down, the rest installed with screws and nut plates. Next I made a doubler plate to splice the F-830 and F-831 back together. Make it wide enough for two rows
of AN426AD3 rivets to attach it to the rear sections of the floor skins, and MS21049-08K nut plates to secure the bulkhead areas of the forward sections. Use K1100-08 (aka MS21049-L08) for the inner floor rib areas. Use K1000-08 for the outer rib areas.
Lay out and drill the rivet and nut plate screw holes into the F-830 & F-831. Clamp the doubler under the two skins while they are clecoed together. Transfer drill all the rivet & screw holes. This will ensure that the new, two piece floor skins will still "line up" after you shear them along the line drawn earlier.
I've got photos of my floors if you'd like to see them. You will be able to get you hands into the area under the rear, riveted section of the flooring for
any future needs.
Charlie Kuss
 
Hi MIke,
Definately do not use #6 screws for ANYTHING with a platenut that you might want to remove one day. They break and strip.

On my 8 I used #8 nutplates for all the floors and use hex screws so a 1/4" socket on a cordless gun gets them out. FOr those pesky areas against the wall, I have a 1/4" flexible drill bit extention from home depot and a 1/4" driver insert for it. CHEAP!
Flexi%20Ext.gif

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Since I have carpet I have not had an issue with either stepping on it, nor have I seen the heads tear up the seat bottoms. I only have 300 hours on the plane though.

I did split my seat floors for easy removal. No particular order or location. Just makes it easy to get em out.

The KEY to all this is the socket head screws. NAS 1096 screws. Ill bet I have 200 of these all over my plane. You cant beat em. It makes it a snap to get em out with a cordless drill, or a ratchet, or whatever. These are the same screws you hear folks talk about on their tank access plates. I have them everywhere. After 2000 flying hours of rv maintanence, I can tell you that these are the only way to go for all your #8 nutplate needs, as well as other places. ACS catelogue page here

If you pull up this hi res image of my rear heat installation you will see several of the screws in use.

Best,
 
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Kahuna said:
Hi MIke,
snipped
On my 8 I used #8 nut-plates for all the floors and use hex screws so a 1/4" socket on a cordless gun gets them out. For those pesky areas against the wall, I have a 1/4" flexible drill bit extension from home depot and a 1/4" driver insert for it. CHEAP!
snipped
The KEY to all this is the socket head screws. NAS 1096 screws. Ill bet I have 200 of these all over my plane. You cant beat em. It makes it a snap to get em out with a cordless drill, or a ratchet, or whatever. These are the same screws you hear folks talk about on their tank access plates. I have them everywhere. After 2000 flying hours of rv maintenance, I can tell you that these are the only way to go for all your #8 nutplate needs, as well as other places. ACS catelogue page here
snipped
Best,
Click to expand...

I used flush head screws everywhere. However, if I had it to do over again, I would have used pan head or better yet, button head screws like Mike suggests above, in areas where the heads won't likely snag on anything, such as the outer side edges of the floor skins. Using them [pan or button head screws] under the seats is a personal choice. I chose not to.
For the RV-8A the NAS1096 screws Mike mentions work great on the forward vertical attach points of both the left side throttle console and the right side switch console. The flanges of the F-802 bulkheads interfere with getting a screw driver onto the Phillips head of the AN hardware Vans supplies. The NAS1096 screws can be easily accessed with the flex extension Mike mentions above, or a 1/4" ratchet set with a 5/16" universal socket and extension. I have a Snap On nut driver handle which has a flexible shaft. It holds 1/4" drive sockets. It's great for getting into those tight places. I really like the NAS1096 screws to! :D
Charlie Kuss
 
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Watch the Corners

I spit the two floor pieces into six smaller parts and put joiner plates under the joints. All the interior screws are countersunk #8's and round heads for the screws near the exterior skins. I used standard platenuts throughout except for the corners. I found that the one lug platenuts (PN k2000 and MK2000) from ACS were much easier to fit into the corners. Would do it the same the next time.

Charlie Becker
N464CB 8A
Finishing Kit
 
Mark,

You might consider this..... It will take considerable effort to replace all the pull rivets with nut-plates and #8 screws. This will also add weight. What will you actually accomplish?

Drilling the heads off soft aluminum pull rivets is very easy. The only delay is removing the heads off the drill bit. Replacing the rivets takes less time than screwing in a #8 screw. I removed the floors from the Doll when I installed the Tru Track roll servo. It took only a few minutes to do. Removing the standard #8 screws from the front floor panel under the pilot's seat took longer than drilling out all of the floor rivets. I recommend that you consider just riveting in your floors as per plan, and simply drilling out the soft rivets whenever you want to remove them. You will save time, effort, money, and weight.

I'd guess that after a few years, at least one or more of the #8 screws that you put in to replace the rivets will strip out, and you will end up drilling out the steel screw instead of the soft aluminum rivet. Think about it!

Others might say that the holes will be messed up drilling out the rivets. I did not have a problem with that, and with care neither will you.
 
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Danny is right

Mark,

Listen to Danny, It does not take much time to dril out the floors, IF you ever need to. I put a couple of water pipe 3/4" under the floors in case I want to add a wire later?
 
Danny & Jay,
My concern with pulled rivets is that after a number of removals, the holes will become enlarged. If you held your centerlines for the drilled holes to the center of the floor rib flanges, you can install 5/32" pulled rivets when this happens. (You will still have edge distance) Often when you drill out pulled rivets, the rivet "spins" in the hole, which enlarges the hole. I don't feel like dealing with installing 3/16" pulled rivets 10 years down the road. But hey, that's just me. As a professional mechanic, I believe in Murphy's Law! :-(
I plan to remove my floors during every annual inspection. I want to check for corrosion, loose hardware and to clean out the inevitable debris (coins, pens, dirt, etc) which will end up down there. I've installed a fair amount of electrical equipment under the floors, so access is important to me.
For a builder with a firewall mounted battery and no equipment under the floors, this won't be an issue.
Installing the nutplates is not that much extra work IF you don't rivet the floor ribs to the F-806 while jigging the fuselage. The other trick to cutting down the effort, is to fit the floor skins while the fuselage is still upside down in the jig. This means that you have ALL the rivet/screw holes drilled in the floor ribs. Remember to drill the belly skins before removing the floor ribs. That way, those ribs can be removed ONE time to do ALL the debur/nutplate fitting/dimpling, while those ribs are on the work bench. This is MUCH easier than standing on your head, trying to fit nutplates in an upright fuselage. ;)
Charlie Kuss
 
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