VAF Forums

VAF Forums (https://vansairforce.net/community/index.php)
-   RV General Discussion/News (https://vansairforce.net/community/forumdisplay.php?f=2)
-   -   K1100 Nut Plate Question (https://vansairforce.net/community/showthread.php?t=83084)

Capflyer 02-25-2012 08:16 AM

K1100 Nut Plate Question
 
On K1100 nut plates, in order to dimple all three holes there is a conflict because of the diameter of the dimple dies will flatten out the other dimpled holes. Curious if it is acceptable to over size the screw hole so the dimple from the piece being screwed in fits into that over sized hole? In the past I just dimpled away and hoped the screw would take care of the larger screw hole dimple.

Mike S 02-25-2012 08:24 AM

You can grind off a bit of the shoulder on the female die, to give clearance for the previously made dimple.

az_gila 02-25-2012 08:49 AM

Change rivets
 
Don't bother dimpling for the attach rivets - then the problem goes away...:)

Just use reduced head NAS 1097 rivets and countersink.

Tom Martin 02-25-2012 10:10 AM

I agree with Gil, use 1097 rivets. In the RV 10 Van called out for a lot of plate-nuts to be dimpled. This is a big waste of time when 1097 rivets work so well for this application.

WingsOnWheels 02-26-2012 12:39 AM

First dimple the screw hole and then use a ground-down 3/32 die for the rivet holes. There are plenty of other areas you will want the modified die, so it won't go to waste.

GAHco 02-26-2012 09:15 AM

Here ya go!
 
You can buy them 8-32 and up with dimples.

Read the tech info pages in this link

http://www.gen-aircraft-hardware.com.../nutplates.pdf

We go by MS numbers, you should be able to find what you are looking for by the pictures and charts.

DeltaTango 02-26-2012 09:20 AM

Small dia. 3/32 die
 
Cleveland tools sells a small dia 3/32 female die. Item Number : DIE4263S
for $18.00.
Dimple the center hole first then use the small die on the sides. Works the same as grinding off one side of a standard die except you do not need to make sure that the flat side is lined up correctly. I use my small dia. die most of the time. I rarely use the standard size. Mostly because the small one is already on the squeezer.

Bob Axsom 02-28-2012 02:43 AM

The Van's Class instruction
 
Do not dimple the platenut mounting holes - countersink them. The only function of the rivets is to hold the platenut in place when the mating screw has not been tightened and the rule of not countersinking metal less than 0.032" does not apply. You do have to be careful but that is the way to do it as taught to me by Van's elite instructors and I have since installed hundreds of them this way and it works perfectly. I use regular NAS426 3/32 dia rivets. This method allows the platenut to sit flush against the back of the part it is mounted on.

Bob Axsom

Capflyer 02-28-2012 03:41 AM

Some good best practices here...thank you all. I've certainly done my share of tool mods so grinding down the sides is a "duhhh" for me, not sure why it hadn't hit me before. I like the idea of the smaller diameter ones as well from Cleveland. My only concern with countersinking the mounting holes if if you go just a tad bit too far the rivet head will not hold but in general not a bad idea.

rockwoodrv9 02-28-2012 09:45 AM

why dimple or countersink them at all?
 
I am a new builder so I don't claim any knowledge, but what is the point of dimpling or countersinking any nut plate other than that is what it shows on the plan? I have a hard time seeing that a dimpled or countersink rivet would be any stronger than a regular rivet. In fact, I think you could make a good argument that because more metal is there with no countersink that it would be stronger left alone. All the rivet does is keep the bolt or screw from spinning. What the head of the rivet looks like does not matter.

Is it just one of the things required to meet the 51% rule like having to fabricate shims and other little pieces that could easily be included with the rest of the kit?

Mike S 02-28-2012 09:52 AM

Quote:

Originally Posted by rockwoodrv9 (Post 634027)
I am a new builder so I don't claim any knowledge, but what is the point of dimpling or countersinking any nut plate other than that is what it shows on the plan? I have a hard time seeing that a dimpled or countersink rivet would be any stronger than a regular rivet.

Has nothing to do with the strength of the rivet, it is all about having a flat surface on top of where you mounted the nutplate.

You do not want rivets sticking up and interfering with the part you are going to be attaching with a screw.

Bob Axsom 02-28-2012 10:05 AM

I see a little need for more exposure here
 
Quote:

Originally Posted by rockwoodrv9 (Post 634027)
I am a new builder so I don't claim any knowledge, but what is the point of dimpling or countersinking any nut plate other than that is what it shows on the plan? I have a hard time seeing that a dimpled or countersink rivet would be any stronger than a regular rivet. In fact, I think you could make a good argument that because more metal is there with no countersink that it would be stronger left alone. All the rivet does is keep the bolt or screw from spinning. What the head of the rivet looks like does not matter.

Is it just one of the things required to meet the 51% rule like having to fabricate shims and other little pieces that could easily be included with the rest of the kit?

Did Mike's absolutely correct answer clear things up for you? It is very important to understand the concept before you start installing platenuts in your airplane.

Bob Axsom

Bob Axsom 02-28-2012 10:13 AM

Well when that happens
 
Quote:

Originally Posted by Capflyer (Post 633942)
Some good best practices here...thank you all. I've certainly done my share of tool mods so grinding down the sides is a "duhhh" for me, not sure why it hadn't hit me before. I like the idea of the smaller diameter ones as well from Cleveland. My only concern with countersinking the mounting holes if if you go just a tad bit too far the rivet head will not hold but in general not a bad idea.

Well, when that happens like a sitiation where you have to drill out the mounting rivets to replace a fixed platenut with a floating platenut you get to practice Maretial Review Board salvage. My MRB action was to enlarge the mounting holes to #30 (yes those in the platenut as well) and use 1/8" dia flathead rivets in place of the 3/32" dia rivets It doesn't change the form, fit or function of the assembly.

Bob Axsom

WenEng 02-28-2012 10:41 AM

Try countersinking a tad too far on scrap....
 
(For nut plates)... you can see that the rivet will "backfill" somewhat and often make an acceptable squeeze. If you countersink for nas1097 rivets and you went too deep, keep going for a normal 426ad3 rivet. I often got the required depth just using the hand deburring tool with the countersink bit. You sure dont need much for those tiny heads. You quickly learn the right looking depth.

rockwoodrv9 02-28-2012 10:43 AM

nutplates
 
Quote:

Originally Posted by Bob Axsom (Post 634035)
Did Mike's absolutely correct answer clear things up for you? It is very important to understand the concept before you start installing platenuts in your airplane.

Bob Axsom

Like I said, Im a new builder. I only know what I have had to work with so far. The only nutplates I have installed are on the spar of the rudder, which also has a backing plate. There is no dimpled skin or anything that would cause the nutplate to not have perfect contact with the backing plate. There is nothing that could ever come in contact with the 1/8" rounded head of the rivet holding the nutplate. Of course, it the skin or metal under the nutplate was dimpled so it interfered with the nutplate keeping it from sitting flat, it would have to be countersunk, but that would be on the underside of the nutplate. Im only on the tail kit and I am sure I will come to a point where it could be necessary to countersink the underside of the nutplate and if that happens, I will do it. My point was so far I haven't seen a place where using a flush or standard rivet to hold the nutplate down made any difference. If there is a reason to use a flush rivet on the nutplates on the rudder, please let me know. I admit I do not have the experience everyone else here has and always open to learn something new - especially when it helps me build a better - safer plane.

krw5927 02-28-2012 10:49 AM

Quote:

Originally Posted by Bob Axsom (Post 634038)
Well, when that happens like a sitiation where you have to drill out the mounting rivets to replace a fixed platenut with a floating platenut you get to practice Maretial Review Board salvage. My MRB action was to enlarge the mounting holes to #30 (yes those in the platenut as well) and use 1/8" dia flathead rivets in place of the 3/32" dia rivets It doesn't change the form, fit or function of the assembly.

Bob Axsom

Common MRB practice on the big certified boys as well.

Mike S 02-28-2012 10:53 AM

Quote:

Originally Posted by rockwoodrv9 (Post 634052)
The only nutplates I have installed are on the spar of the rudder, which also has a backing plate.

Now I understand what is causing you a bit of confusion.

The nutplates you have are for the rod ends that are used as pivot bearings for the rudder. They are probably i/4" or 5/16" thread size. There is not an issue with clearance there.

Later, you will be installing a lot of #6. and #8 size nut plates, which will be used to fasten a part flat on the part the nutplate is mounted to, like inspection covers, or the fairing at the tail. In this case, the surface on top of where the nutplate is mounted must be flat, thus the dimple/countersink for the rivet.

gasman 02-28-2012 11:03 AM

If you happen to have a Knipex 8603-180 7 inch wrench, just use 426A (soft) rivets for most all of your edge nut plates.

rockwoodrv9 02-28-2012 11:07 AM

got it!
 
Quote:

Originally Posted by Mike S (Post 634062)
Now I understand what is causing you a bit of confusion.

The nutplates you have are for the rod ends that are used as pivot bearings for the rudder. They are probably i/4" or 5/16" thread size. There is not an issue with clearance there.

Later, you will be installing a lot of #6. and #8 size nut plates, which will be used to fasten a part flat on the part the nutplate is mounted to, like inspection covers, or the fairing at the tail. In this case, the surface on top of where the nutplate is mounted must be flat, thus the dimple/countersink for the rivet.

Thanks for the info. Got it now. I read and reread the nutplate instructions and can see where you are talking about. Since I hadn't gotten anything other than those on the rudder spar, I couldn't see that it made a difference on what type of rivet I used. I will look ahead at the plans and see what places I will need to use dimpled or countersinking and make sure I have it figured out first. Thanks.

Mike, now would be a good time to be in Cameron Park. We got 12" of snow so far last night and it is still coming down like crazy. My satellite dish is covered and we are not getting TV! ugg!

Mike S 02-28-2012 11:32 AM

Quote:

Originally Posted by rockwoodrv9 (Post 634074)
Mike, now would be a good time to be in Cameron Park. We got 12" of snow so far last night and it is still coming down like crazy. My satellite dish is covered and we are not getting TV! ugg!

Oh well, at least your internet hookup is still working:D

Mike S 02-28-2012 11:44 AM

Take a good look at the setup next to the multimeter box, bottom of the vert row, you can see the flush rivets and the countersunk nutplate, and the cover piece with the countersink all in relation to each other.

When a flat head screw is inserted here, the cover will be flat on the bulkhead frame, and the outer surface of the cover will be smooth.

Not the greatest photo, but best I could find on short notice.

Hope this makes it a bit clearer :confused:



All times are GMT -6. The time now is 09:07 AM.