Dimpling platenuts

I was not very happy with look of the dimpled platenuts when I did the elevator trim access panel and am about to do the platenuts on the tank joint plate and the access panels on the wing skins. I notice some people advocate countersinking the skins rather than dimpling, any opinions? (or tricks to make the dimpled platenuts fit better)

Thanks

While my plane is a QB and I didn't have to do that task, would you be able to use oops rivets (NAS1097)? They can go into thinner skins because the countersink is a lot smaller.

How thick are the skins there? I believe the min thickness for countersinking NAS1097AD3 rivets is .025.

Use NAS1097AD3-x rivets w/nutplates

As Scott mentioned, NAS1097AD3-x rivets are ideal for installing nutplates in relatively thin material (i.e. .032" and thinner). Countersink the skin...but you don't have to go nearly as deep as you would for an AN426AD3-x rivet. Just a quick turn or two with the deburring bit or a 3/32" pilot countersink cutter, and your NAS1097 rivet will sit flush.

Van's sells these rivets. Just grab 1/8 or 1/4 pound of NAS1097AD3-3.5 and you should be good to go. May as well order some "OOPS" rivets while you're at it, such as NAS1097AD4-3.5 and/or -4. Never know when those might come in handy.

http://www.vansaircraft.com/public/parts.txt

NAS1097AD3-3 RIVETS (LB) $27.31
NAS1097AD3-3.5 RIVETS (LB) $29.45
NAS1097AD3-4 RIVETS (LB) $23.25
NAS1097AD3-6 RIVETS (LB) $26.95
NAS1097AD4-3.5 OOPS RIVETS (LB) $22.71
NAS1097AD4-4 OOPS RIVETS (LB) $17.00
NAS1097AD4-5 OOPS RIVETS (LB) $15.00
NAS1097AD4-6 OOPS RIVETS (LB) $18.62

)_( Dan
RV-7 N714D
http://www.rvproject.com

counter sink the platenuts.

I just used my deburing tool to countersink the platenuts. Use standard rivets and leave the skin alone. Remember that the rivets are only holding the platenut so that it doesn't fall off. The screw and platenut is where the strength comes from.

Kent

countersink the platenuts

If I understand this correctly you countersank the platenuts and dimpled the skin??

nope. Countersink the skin and leave the platenut flat.

I'm Confussed

I am very interested in this thread, but you guys contradict each other here:

kentb said:

I just used my deburing tool to countersink the platenuts. Use standard rivets and leave the skin alone. <snip>

Click to expand...

vs.

kevinh said:

nope. Countersink the skin and leave the platenut flat.

Click to expand...

C-sink the skin, use NAS1097, call it a day

Countersink the skin for NAS1097AD3 rivets, don't touch the nutplate call it a day.

I also think there's some terminology confusion here. "Dimpled nutplates" may mean two different things to two different people.

There's the question of whether the nutplate accommodates a FLUSH fastener (i.e. 100-degree head screw), such as the K1100 nutplates, or a protruding fastener (i.e. pan-head screw), such as the K1000 nutplates.

Then there's the question of whether the nutplate RIVET holes are dimpled to accommodate dimples in the skin for rivets.

When you say "Dimpled nutplates" to me I interpret that to mean the rivet holes are dimpled. Wicks does sell nutplates with dimpled rivet holes, I believe, but they're expensive. I instead recommend always using standard K1000 or K1100 nutplates (non-dimpled for rivets) and just using NAS1097AD3-x rivets, with the SKIN countersunk (slightly).

Does this clear it up?

)_( Dan
RV-7 N714D
http://www.rvproject.com

Countersink for rivets, dimple for screws

dan said:

I instead recommend always using standard K1000 or K1100 nutplates (non-dimpled for rivets) and just using NAS1097AD3-x rivets, with the SKIN countersunk (slightly).

Click to expand...

One more point of clarification. The skin is countersunk for the RIVETS. It would be dimpled for the SCREW, if the screw was supposed to be flush. Make sense?

)_( Dan
RV-7 N714D
http://www.rvproject.com[/QUOTE]

D.s.c.p.

Dimple the Skin and Counter sink the Platenuts.

Here is my reasoning.

Use standard rivet and dimpled skin. Normal strength (Maximum) here. Counter sink the platenuts. They are steel and the removal of material here will still leave good strength. I guess the maximun strength would be to dimple the platenuts, but I don't like the looks of that.

The bottom line is that I do what is the least trouble, as I said before the strength of the rivet connect is not that important because you just need to keep the platenut from falling off until the screw is in place.

Enjoy your nuts.

Kent

kentb said:

I guess the maximun strength would be to dimple the platenuts, but I don't like the looks of that.

Click to expand...

What is it that y'all don't like about the looks of dimpling the platenuts?

PJ

In my case the end result (for the elevator trim access panel) was that the skin was a little deformed when all the dimpling of the screw and rivet holes was done and the platenuts were installed which meant the access panel did not fit quite as flush as I would have liked. I was looking for a better method for the wings.
I like the sound of the approach with the different rivets and slight countersinking of the skin such that the platenuts sit flat on the skin.

I dimpled the platenuts with the c-frame and a 2lb hammer using a female dimple die that has a flat machined into it to provide clearance for the platenut. I have also used the pneumatic squeezer with good results. Worked great for me.

On the skin, I dimpled the screws holes first, then I dimpled the rivet holes using this same female die so I wouldn't deform the the dimple for the screws. Then rivet the platenuts on using AN426AD3-3.5.

The end result was IMHO nice and flush. There are several ways to acheive good results. I found this to be one of them. Not better than the methods mentioned above, just a diiferent method.

Bryon

Just one guy's experience but I had no problem with dimipling the platenuts - that is the rivet holes in the platenuts. Seems to work fine and the skin dimple fits in well. You may have to grind the female dimple a little on one edge to clear the protrusion for the main fastener on the nut plate, and it takes me a good whack on the C-arm mandrel to do it. Van's comments that doing the little grind doesn't affect the usefulness of the die for regular dimpling. Bill

Dimple platenuts

Well I tried the dimpling with a flat ground on the die and it worked out fine, thanks for the tips.

Glad it worked. Bill