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Dimpling Nutplates

rv8gibbo

Well Known Member
I worked out a cheap & easy way to dimple Nutplates today without buying or grinding down the edge of dimples. Simply take a piece of 1/4 steel about for inches square, drill a #40 hole close to the edge (so the countersink for the screw clears the edge) then machine countersink the hole so an AN426AD3 rivet sits just below the surface. Now simply use plate as female side of die. I used mine the the bottom on the DRT2 and it worked great, also I straightened the Nutplate out due to distortion of the dies by leaving the weight down on the handle and slightly stretching them down.
 
Dinpling Nuplates

Thanks for the great idea. I never thought of that. I'll be sure and try it out tonight. Seems like it's almost too easy!

I worked out a cheap & easy way to dimple Nutplates today without buying or grinding down the edge of dimples. Simply take a piece of 1/4 steel about for inches square, drill a #40 hole close to the edge (so the countersink for the screw clears the edge) then machine countersink the hole so an AN426AD3 rivet sits just below the surface. Now simply use plate as female side of die. I used mine the the bottom on the DRT2 and it worked great, also I straightened the Nutplate out due to distortion of the dies by leaving the weight down on the handle and slightly stretching them down.
 
At your own risk

Gents,

The DRDT-2 is fine tool but it was designed to dimple aluminum and not steel nutplates. The loads imposed dimpling nutplates may damage the DRDT-2 clamp.

When I dimple nutplates I use my hand squeeze which is designed to handle the higher loads.

If you own a DRDT-2 and are considering dimpling nutplates I would highly recommend against it.

Build on......................
 
Now you tell me! I dimpled a lot of nutplates using a steel adaptor plate similar to described above. As far as I can tell my DRDT-2 is still working okay.
 
The leverage arm on my DRDT-2 broke at the top of and under where the press fit black oxide pivot pin went through. I believe the reason was from the added pressure required to dimple the nut plates. I had to re-weld mine at that point and I reinforced that area with some extra passes of welding rod filler. I ground a side off of the male and female dies and also needed that set for dimpling some of the tight spots in the airframe.
 
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Ok maybe that's not such a good idea. What about pneumatic squeezers will they be ok to load up????
 
... used NAS 1097 rivets, makes it a lot easier...

Good advice. It's a well-known secret that Van's carries NAS1097 rivets in
three AD3 sizes now as well as the AD4's they tout as "oops" rivets.

Search at the Van's Aircraft webstore (be sure to check "The List") for NAS1097.

--
Joe
 
Avery 3/8" Diameter Dimple Die

I used a 3/8" diameter female dimple die from Avery Tools in my pneumatic squeezer. It works perfectly for dimpling nutplates:

DimpleDie.jpg


They're on sale now at Avery Tools:

http://www.averytools.com/prodinfo.asp?number=14870
 
Dimpling nut plates

I use the die shown in the previous post in a hand squeezer...works great. Not hard at all...
 
Help me understand. The NAS 1097 rivets have a smaller head but they are still flathead rivets. How can you use them without dimpling? Or are you saying the dimples were small enough that you could accept the nutplates being slightly proud?
 
The 1097 - 3 rivets have a very small head, countersinking even .025" thick skin will not open up the hole any more than what is necessary for the countersink. Nut plates only need to be held in place to keep them from rotating, the small counter sink is more than adequate for this.
 
good grief

just stick them in a hand sqeezer and dimple the things.

Do we have to make every simple thing an ordeal?
 
just stick them in a hand sqeezer and dimple the things.

Do we have to make every simple thing an ordeal?

Do we have to pick apart every post when someone asks a question? Maybe we should pick at spelling mistakes. Good grief is right.
 
1097s = very light countersink and work well

I don't see any big deal about this. Everyone has their own practice. So what? I don't like to dimple a base metal, then dimple the nutplate when all I have to do is do a slight countersink with a deburring cutter to the base metal and nothing to the nutplate. Spin spin spin and its done. I would always use 1097s 1st and dimple as a last resort with nutplates. But, thats just me. Besides, too much squeezing gave me tennis elbow. Lighten up everyone. Jees.
 
It may be a simple thing were discussing here, but isn't it the whole reason were apart of a great RV community..... I`m going to order some 1097`s tomorrow and run with them. Thank`s for reply`s guys.
 
I think the point that I was making (apparantly not too well) is that this community seems to be suffering from more and more paralysis by analysis. I'm certainly happy to explore issues when they justify the analysis, but it seems that a lot of builders are over thinking every part of the build process.

i'm not advocating being uninformed, but a happy medium will lead the builder to actually spend their time building instead of thrashing forever on minutia.

I'm also equally sure that I will not changw ANY opinions on this among the worst offenders. :D
 
Help me understand. The NAS 1097 rivets have a smaller head but they are still flathead rivets. How can you use them without dimpling? Or are you saying the dimples were small enough that you could accept the nutplates being slightly proud?
I built two RV's and made everything removable with screws and nutplates. At no time did I ever feel a need to dimple any nutplate which in my mind is a kludgy way to do things. Production shops routinely use 1097's in aircraft production, why shouldn't you? An archive search will reveal much information on the subject. Here is one link with images that graphically demonstrates the possibilities using NAS1097AD3 rivets:
http://www.vansairforce.com/community/showthread.php?t=56010&highlight=1097+rivets
 
I built two RV's and made everything removable with screws and nutplates. At no time did I ever feel a need to dimple any nutplate which in my mind is a kludgy way to do things. Production shops routinely use 1097's in aircraft production, why shouldn't you? An archive search will reveal much information on the subject. Here is one link with images that graphically demonstrates the possibilities using NAS1097AD3 rivets:
http://www.vansairforce.com/community/showthread.php?t=56010&highlight=1097+rivets

Rick:

My RV-6 has been flying almost 15-years and has almost 2,600 hobbs hours on it. I, like you, did not waste my time or energy dimpling nutplates and I also used them everywhere something comes apart. Yes I agree that it is a kludgy way to do things by dimpling them.

I have not had any issue with any of the nutplates 15-years and 2,600 hours after installing them WITHOUT dimpling them.
 
I built two RV's and made everything removable with screws and nutplates. At no time did I ever feel a need to dimple any nutplate which in my mind is a kludgy way to do things. Production shops routinely use 1097's in aircraft production, why shouldn't you? An archive search will reveal much information on the subject. Here is one link with images that graphically demonstrates the possibilities using NAS1097AD3 rivets:
http://www.vansairforce.com/community/showthread.php?t=56010&highlight=1097+rivets

I hate plate nuts.

The manufacturing tolerances are not precise at all. They are too tight, especially for #6 and #8 screws. I open them with a tap to make them useful. There's nothing more frustrating than stripping out a screw head half way in and having to spend time getting it out and starting over again. Sometimes Bolub or a spot of oil works but not always as some are simply too tight.

It never occurred to me to dimple the two attach holes. It would provide for a more precise install but it won't fix the issue of being under cut.
 
Thanks Gary and Rick....

Rick:

My RV-6 has been flying almost 15-years and has almost 2,600 hobbs hours on it. I, like you, did not waste my time or energy dimpling nutplates and I also used them everywhere something comes apart. Yes I agree that it is a kludgy way to do things by dimpling them.

I have not had any issue with any of the nutplates 15-years and 2,600 hours after installing them WITHOUT dimpling them.

After having gone through the process of dimpling all my trim tab servo cover nut plates, and then seeing how easy it was to use the 1097 rivets on the servo mounting bracket, I too am now in the camp of using the 1097s and countersinking as opposed to dimpling the nut plates. I too will most likely make many of the floor panels and other parts removeable, which means a lot of nut plates in my future. I think that using the 1097s is easier than having to dimple each rivet hole in the nut plate, and yes, that is my preference. To each their own in a free country.

Gary, I appreciate your statement about no problems after your long period of use. It further solidifies my decision to continue to use the 1097s. Now if I would only have read Rick's posts before I did the trim cover plate!
 
Ok...I had never thought of dimpling a nut plate. While riveting the nut plates in place on my elevator trim attachment plate I noticed the nut plate did not mate perfectly with the end dimples in the material.

Since Vans instructions make no reference to countersinking or dimpling the nut plate....I just built on using the prescribed 426 rivets. the nut plates are completely serviceable and they are not "structural" in nature on this part but they do sit slightly proud on top of the 2 end dimples.

As mentioned in this post, this is an acceptable practice but I'd like to hear more opinions. I am not looking to debate 1097 rivets vs 426 but I'd like to know if dimpling or countersinking nut plates is required.
 
Ok...I had never thought of dimpling a nut plate. While riveting the nut plates in place on my elevator trim attachment plate I noticed the nut plate did not mate perfectly with the end dimples in the material.

Since Vans instructions make no reference to countersinking or dimpling the nut plate....I just built on using the prescribed 426 rivets. the nut plates are completely serviceable and they are not "structural" in nature on this part but they do sit slightly proud on top of the 2 end dimples.

As mentioned in this post, this is an acceptable practice but I'd like to hear more opinions. I am not looking to debate 1097 rivets vs 426 but I'd like to know if dimpling or countersinking nut plates is required.

This is what I was taught in the Sportair class I took last year. When it came time to rivet a nutplate, I specifically asked the instructor (Ed McGowin, who to my knowledge has quite a few builds under his belt) how to dimple or countersink the nutplate. He told me neither was necessary.

Now I'm pretty curious to hear if this was bad advice.
 
Nutplates need to sit flush on the surface, just riveting them to dimpled holes is unacceptable. If the material is thick enough, lightly countersinking and using the 1097 rivets is fine, if the material is very thin then I would dimple both.
 
YES!

So glad I found this old thread. I was looking for a way, ANY WAY, out of dimpling any more nutplates, EVER! Lol. I have a Main Squeeze, which is freaking awesome, but I do not have a yoke that will accept the other half of the die set and I do not have a reduced diameter female die. I got through the 18 nutplates on my RV-12 VS by grinding off the front of my vise-grip dimpler female die and using that. However, it takes a huge amount of force and the vice-grips could not be released by hand so I had to use a channel lock pliers on the vice-grip release after every squeeze. And the nutplates get slightly bent in the process so then had to straighten them out - one of them snapped in half doing this. So yes, I agree dimpling nutplates is for the birds and I will not be spending ~$150 on a yoke and die to let me do it in the Main Squeeze. I also tried machine countersinking the nutplate, but I wasn't too thrilled about that either. Thanks to the VAF community I have ordered the "OOPS HOLE SAVER RIVET KIT" from Aircraft Spruce and hopefully will never look back!
 
I hate plate nuts.

The manufacturing tolerances are not precise at all. They are too tight, especially for #6 and #8 screws. I open them with a tap to make them useful. There's nothing more frustrating than stripping out a screw head half way in and having to spend time getting it out and starting over again. Sometimes Bolub or a spot of oil works but not always as some are simply too tight.

It never occurred to me to dimple the two attach holes. It would provide for a more precise install but it won't fix the issue of being under cut.

They are not undercut or necessarily out of tolerance. They are, by design, deformed to provide a vibration proof attachment, much like a nyloc nut.

That said, yes, some are just too tight. Running a tap through them will allow easy installation and removal but eliminates the locking ability...

Another thing to consider is if you are using a drill/driver to install or remove the screws. Try removing a screw with a drill then see how hot the screw is...it may surprise you...
 
So glad I found this old thread. I was looking for a way, ANY WAY, out of dimpling any more nutplates, EVER! Lol. I have a Main Squeeze, which is freaking awesome, but I do not have a yoke that will accept the other half of the die set and I do not have a reduced diameter female die.

I'm confused. Do you only have no-hole yokes? A male/female dimple die set should fit into any standard yoke.
Regarding the reduced diameter female die, just grind one side of the die down to clear the center of the nutplate. I did just that 25 years ago and still use that die for all 3/32 dimples and nutplates.
 
Dimple nut plates

I'm confused. Do you only have no-hole yokes? A male/female dimple die set should fit into any standard yoke.
Regarding the reduced diameter female die, just grind one side of the die down to clear the center of the nutplate. I did just that 25 years ago and still use that die for all 3/32 dimples and nutplates.

Same here. I process in batches. Check grip with a tap lubed with Boelube. Usually 2 turns leaves them perfect with enough grip to hold yet not so tight the screw galls.
Diimple the ears with the c-frame
Wash with lacquer thinner
Prime with NAPA 7220. I have a board with 40 nails. Makes it quick.
Yes, I know, not needed and total overkill, but I've found bad ones so tight the screw wouldn't go in or out and it was after they were installed. Now I just grab a pimed one and I know it's good.
 
Pre-dimpled nutplates

I've bought dimpled nutplates, in the same sizes that Van's use in many applications. It gives me a choice, and if my memory serves me correctly it's the same part number with a "K" at the end.
 
Dimpled nutplates

The glaring question I have to ask is
why not just get dimpled nutplates?
 
Nut plate

I am really not sure why this is even an issue; it takes like five seconds to dimple the mounting ears on a nut plate with a hand squeezer.
 
Agree . . .

I am really not sure why this is even an issue; it takes like five seconds to dimple the mounting ears on a nut plate with a hand squeezer.

Or just use NAS rivets. A flush head can install a nut plate in .025 material just fine. And much less time investment in the entire process.
 
I've bought dimpled nutplates, in the same sizes that Van's use in many applications. It gives me a choice, and if my memory serves me correctly it's the same part number with a "K" at the end.

IIRC the part number with the K suffix is manufactured to accept a dimple nested into the center hole - the threaded one - for use with flat head screws. The discussion here concerns dimpled ?ears?, the ones usually riveted on.
 
There are dimpled nutplates available from Van?s, they are supplied in the RV-12 kits. They have a ?D? suffix (i.e. K1000-08D). Not sure what additional sizes are available, as others have said, pretty quick to just dimple standard nutplates or use NAS rivets.
 
IIRC the part number with the K suffix is manufactured to accept a dimple nested into the center hole - the threaded one - for use with flat head screws. The discussion here concerns dimpled ?ears?, the ones usually riveted on.

The part number for some of the ones I bought were MS21047L06K, and these certainly had the dimpled ears for countersunk rivets. The part description is "6-32 THREAD, SELF-LOCKING NUTPLATE, TWO LUG, LOW HEIGHT, CADMIUM PLATED CARBON STEEL, 450 DEG F, WITH DRY-FILM LUBE, COUNTERSUNK RIVET HOLES

ALT. PART NUMBER: NAS680A06K"
 
Or just use NAS rivets. A flush head can install a nut plate in .025 material just fine. And much less time investment in the entire process.

A seasoned builder saw a dimpled nutplate on my project and asked why in the world I would do that. Told me about NAS1097 rivets. I started using them and never looked back.
 
Or just use NAS rivets. A flush head can install a nut plate in .025 material just fine. And much less time investment in the entire process.
Dang, looks like the RV-12 skin is only ~0.018, at least the piece I measured, which was the rudder. Steps away... Ok, got about 0.023 on the VS where the 18 nutplates were, not sure if that is 0.025 nominal?
 
Dang, looks like the RV-12 skin is only ~0.018, at least the piece I measured, which was the rudder. Steps away... Ok, got about 0.023 on the VS where the 18 nutplates were, not sure if that is 0.025 nominal?

Yes .025 as stamped on the sheets. It may work for thinner, you should try it before committing to its use.

I like the NAS as you can just countersink with the deburring tool. I do 7 rounds and it is done. YMMV as always.
 
I first tried using the Cleaveland tools “Tight-Fit dimpling Mixture” and it was very scary and tough to do. I carefully used the ram for the C-Frame tool and then drove the male end into the female mounted dye. It worked Ok but the nut plates were not sitting as flush as I wanted. I tried to hit them again harder but it was not effective enough to proceed with the flush rivets Called out in the plans.

So I decided to grind down my female dye after looking at the small amount required to make it fit and be able to use my hand squeezer. I marked the edge so I could line up the nut plate.

With the mechanical advantage of the squeezer these nut plates came out great and they stayed flat. Really pleased with the results so I thought I would share.

Allen
RV-14A (Elevators step 2 Page 09-12)
 

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Hmm I've always just dimpled them with a squeezer, seem to get good results.

I open them with a tap to make them useful.

I've used a ton of different kinds of nutplates and never had to tap one; Boelube alone has always done the trick. Maybe it's necessary some times but it shouldn't be done as a matter of course. There are good reasons not to compromise the self-locking feature.
 
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