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My first rivets... How do my shop heads look??

J

jmilton

Active Member
So I started to rivet the VS spar Saturday & today... perhaps I should have asked after the first one but I'm curious how the shop heads look. I know a couple are not perfectly flat but I think they turned out pretty good.

I would love to get the opinion of the trained eye here... note the angle makes them look not so flat when they are actually pretty flat.

Thanks All!

144966810145ac230bb2b39.jpg
 
Excellent! Thanks Paul.

I've moved onto the rest of the VS spar and they all look pretty much just the same. I'm starting on the flush rivets at the bottom of the spar tomorrow. Next experience with a little fear written on it is using the rivet gun on the skins when the time comes.

Either way I'm enjoying the ride. I look forward to the next 13,990 rivets! And I will see every one of them as I dont expect to have the means to go QB. :)

Cheers!
 
Get a shop head gauge and take all the guesswork out of the equation. After a few you won't need the gauges...but when you're just starting out it's a big help imho.
 
dan said:
Get a shop head gauge and take all the guesswork out of the equation........
Click to expand...
Sage advice. It is very difficult to tell from the photo but based upon what my eye perceives, I would suppose the rivets, while perfectly acceptable are near the maximum limit of "flatness." Even though I pounded rivets for a living, I may be all wet but why guess? :confused: You've got a lot of rivets to shoot. A rivet gauge is a simple and unambiguous reference tool to work with and will remove all doubt. Get the 3/32" and 1/8" variety and for the next 13990 rivets, strive to consistently maintain a middle ground between minimum and maximum shop head height.
 
Make a gauge

Make a rivet gauge from a piece of scrap aluminum. Drill a 9/64 hole for the 3/32 rivets and a 3/16" hole in the opposite end for the 1/8 rivets.

Regards,
 
Measuring rivets... old posts

I prefer the answer in this previous posting (not mine, but a link to my web site... :) ...)

The gauges only give the dimensions of a perfect rivet, and is a good thing to strive for, but a go/no go criteria should be used for each rivet.

A gauge won't answer Rick's question.... get a depth micrometer and tell us what the height of those rivets pictured actually is....

------------------------------

There is another, cheaper and simpler solution- throw away your rivet gauge.

The commonly available rivet gauges are not based on the true minimum size for an acceptable rivet, per the Mil-Spec on riveting. I suspect that thousands of perfectly acceptable rivets have been drilled out over the years, because they didn't pass according to the gauge.

This is something I demonstrate on every initial tech counselor visit that I do (just did it yesterday, in fact.) Use a dial caliper to accurately measure the height and diameter of the shop head, and compare it against the table in the Mil-Spec. Then compare that against the rivet gauge. The results will surprise you. Did you know that a 3/32 and 1/8 rivet can both have shop heads of the same height (.050") and be within acceptable limits?

http://home.earthlink.net/~gilalex/

__________________
Jeff Point
RV-6 flying
RV-8 tail kit
Milwaukee

---------------------

A read of this previous posting might also be useful when measuring of rivets is involved....

http://www.vansairforce.com/community/showthread.php?t=12446&page=3&pp=10&highlight=rivet+gauge

Let us know some actual dimensions for these particular rivets...

gil in Tucson
 
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Say What?

az_gila said:
I prefer the answer in this previous posting....the gauges only give the dimensions of a perfect rivet......A gauge won't answer Rick's question....There is another, cheaper and simpler solution- throw away your rivet gauge.....This is something I demonstrate on every initial tech counselor visit that I do.....
Click to expand...
Gill;

Wow. Where do I begin? "Throw away your rivet gauge?" A good rivet gauge is EXACTLY a go/no go gauge. The enclosed photo illustrates typical Boeing approved rivet gauges and I don't care if you have set a million rivets. When an inspector routinely checks your work and asks to use your gauges...you better have a set of these handy and as shown, are exactly the measure by which all solid rivets are judged. As you can see in the photo, the gauge is used as a go/no go tool, one side for measuring the minimum height and the other side for measuring the acceptability of diameter of the shop head. In actuality, there is a significant range in the acceptability of the height of the shop head. This tool quickly lets you know if it meets that standard. If there is simpler approved tool to quickly and precisely determine the acceptability of the shop head in a high quality production environment, I freely admit I am not aware of it's existence and perhaps you can enlighten me.

fueltanks10ki2.jpg
 
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Rick6a said:
Gill;

Wow. Where do I begin? "Throw away your rivet gauge?" A good rivet gauge is EXACTLY a go/no go gauge.
Click to expand...
OK, confession time. I use a rivet gauge and have since the day I drove the first rivet, although sometimes I can't get a rivet gauge onto my work (the bottom skin rivets come immediately to mind) so I've trained my finger to tell.

That said, I admit, there are times when I've driven the rivet too much and gotten it slightly flatter than I should have.

And I left them in place.

I have to admit sometimes I use the gauge to tell me how far off I was more so than which rivets to drill out.

Oh, btw, I think those rivets look fabulous. I'd be proud to show 'em to anyone.
 
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Thanks for all the sage everyone. I will take a couple more pics and post them to show the rivet work on the rest of the spar so far.

I do have a set of rivet guages on order, I just couldn't wait for them to show up to begin. :) I'm hoping to see those show up today or tomorrow. In the meantime I may drill a piece of scrap for an interim device. Since I am using the "main squeeze" riveter I am still learning where to adjust it up for the right rivets, as well as trying to keep it straight with the piece while squeezing.

Cheers!
 
There are good gauges and poor gauges...

Rick6a said:
Gill;

Wow. Where do I begin? "Throw away your rivet gauge?" A good rivet gauge is EXACTLY a go/no go gauge. The enclosed photo illustrates typical Boeing approved rivet gauges and I don't care if you have set a million rivets. When an inspector routinely checks your work and asks to use your gauges...you better have a set of these handy and as shown, are exactly the measure by which all solid rivets are judged. As you can see in the photo, the gauge is used as a go/no go tool, one side for measuring the minimum height and the other side for measuring the acceptability of diameter of the shop head. In actuality, there is a significant range in the acceptability of the height of the shop head. This tool quickly lets you know if it meets that standard. If there is simpler approved tool to quickly and precisely determine the acceptability of the shop head in a high quality production environment, I freely admit I am not aware of it's existence and perhaps you can enlighten me.

fueltanks10ki2.jpg
Click to expand...


Rick... most builders do not have access to the gauges you show... they are not advertised in any of the usual builder's tool catalogs.

I was referring to these gauges originally made by Avery, and now sold by many folks.... These are definitely not go/no gauges, and are the rivet gauges that most non-professonal builders think of...

shopheadrivetgauges.jpg


If you read the link to my previous posting, I actually recommend folks make their own go/no go gauges...

The only one I have seen advertised is the Clear Tools one, and that does not meet the usual FAA requirements since it uses 1.5 D as a maximum shop head diameter.

More importantly, where can us non-Boeing types buy the gauges you show?

They are far better (and more useful) than any others I have seen... Note the crisp, sharp edges for the height measurement vs. the rounded edges of the Avery tool - which probably doesn't make a lot of difference, since the Avery tool is sized for a "perfect" (perhaps I should use the word "optimum"?) 1.5 W by 0.5 H shop head..... :)

gil in Tucson
 
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Guage Interpretation

Gil / Rick -

Given that the Avery guages are not "go/no go" quality, how do you recommend we interpret them when we have a rivet that meets the criteria of one end (diameter) but not the other end (height)?
 
Make a height gauge...

Gsuit said:
Gil / Rick -

Given that the Avery guages are not "go/no go" quality, how do you recommend we interpret them when we have a rivet that meets the criteria of one end (diameter) but not the other end (height)?
Click to expand...

UPDATED - numbers corrected - see later posts

Clayton,

Use a height gauge.... it can be as simple as a strip of metal that is the thickness of the minimum height of the shop head.

If your shop head is higher than the thickness of the end of the strip, it's good to go...

Heights are here...

http://home.earthlink.net/~gilalex/

....and are 0.038 for -3 rivets and 0.050 for -4 rivets. You'll have to file a strip down slightly if you want and accurate thickness gauge for the -3 rivets, but if you have a micrometer you can borrow it should be easy enough...

I nicely machined one like Rick's Boeing one would be nice though....

gil in Tucson
 
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az_gila said:
Clayton,
....and are 0.032 for -3 rivets and 0.042 for -4 rivets.
gil in Tucson
Click to expand...

Gil,
I think you gave here the heights for the manufactured head (Table II). The one we mostly care about is the driven head (Table III), and sizes are respectively 0.038 and 0.050

Just my ?0.02 :)
 
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Oops....

FlyingArcher said:
Gil,
I think you gave here the heights for the manufactured head (Table II). The one we mostly care about is the driven head (Table III), and sizes are respectively 0.038 and 0.050

Just my ?0.02 :)
Click to expand...

Daniel... you are correct with whatever units of currency your 0.02 are in...
Sorry to all for the mistake... and I wasn't even typing after midnight... :)
At least I did call it the shop head... :)

I'll correct the above post.

thanks gil A
 
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Rivet Tolerances

I was told by Van's years ago that the actual mil specs of the rivets can be as much as 50% more tolerance than what is considered "acceptable". i.e. 1 1/2 diameter could be as little as 1 1/4 or as great as 1 3/4.
Buy the guage, get your eye and finger calibrated, and keep pounding away. Get good at drillling out the bad ones and leave a few if you think more harm than good can come of redoing them. There has never been a structural failure of a Vans aircraft that I am aware of due to bad riveting and thousand of amatures have built these things. They are designed to be built by amatures and they are not space ships or airliners. Have fun.
 
Real numbers...

JonJay said:
I was told by Van's years ago that the actual mil specs of the rivets can be as much as 50% more tolerance than what is considered "acceptable". i.e. 1 1/2 diameter could be as little as 1 1/4 or as great as 1 3/4.
......
Click to expand...

Or you could read the actual numbers here....

http://home.earthlink.net/~gilalex

gil in Tucson
 
I agree with Rick and Gil's "aim for precision" whenever possible, but here's more fuel for the "don't drill them out unless they're really bad" argument...

Don't forget what you read in Section 5 of your builder's manual. Van's occasionally uses smaller than ideal rivets that (to paraphrase from memory) are more than adequate for the job. Not sure if they're talking about smaller than the standard rule of thumb shop head or smaller than mil-spec, but Van's has engineered into the design smaller shop heads in places where going to the next larger rivet would probably make them just slightly too long to buck consistently well. One place I've noticed this the most is on the wing skins. I called Van's about the rivets seemingly to be a little too short to get good shop head height or width--unless you hit the rivets EXACTLY perfect. They indicated that if I used the rivets called for on the plans, they would be more than strong enough, even if not within spec. Sure, you could cut down all 2500-or-so rivets on the wing skins, but it's probably not real practical.
 
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Sizes...

alpinelakespilot2000 said:
I agree with Rick and Gil's "aim for precision" whenever possible, but here's more fuel for the "don't drill them out unless they're really bad" argument...

Don't forget what you read in Section 5 of your builder's manual. Van's occasionally uses smaller than ideal rivets that (to paraphrase from memory) are more than adequate for the job. Not sure if they're talking about smaller than the standard rule of thumb shop head or smaller than mil-spec, but Van's has engineered into the design smaller shop heads in places where going to the next larger rivet would probably make them just slightly too long to buck consistently well. One place I've noticed this the most is on the wing skins. I called Van's about the rivets seemingly to be a little too short to get good shop head height or width--unless you hit the rivets EXACTLY perfect. They indicated that if I used the rivets called for on the plans, they would be more than strong enough, even if not within spec. Sure, you could cut down all 2500-or-so rivets on the wing skins, but it's probably not real practical.
Click to expand...

Steve... I'm sure that this would be referring to double dimpled parts... excuse the poor drawing, but it shows the shape of the hole we are filling....

cs_rivet.gif


Since the dimple leaves a sort of tapered back side (can I say that... :) ...) to the hole, some of the shop head is sort of hidden.

In this case, I would go for the width being within limits, rather than the height....

But personally, I mostly used rivets a 1/2 length longer than called for (old RV-6 plans) and had little trouble.... The 1.5 D "exposed before driving" rule is really for clean, parallel holes, not the funny holes created by our double dimples, as shown in the picture above...

gil in Tucson
 
When I reinstalled my bottom skin after replacing the rear spar doubler last week, I "upgraded" all the rivets by .5 to get the "proper" height/width.

But there are plenty of spots where Van's calls out rivets that have no hope of yielding the perfect rivet. One I can think of offhand is the two spacer bars on the 7 center section. They're just to be held in place until the wing spar is installed.

Some nutplates, it seems to me aren't that dependent on the perfect rivet since they're just intended, I guess, to hold the nutplate until a screw makes it way into one.

And I've had Van's look at some work and some rivet callouts that clearly would not yield the proper size buck and say "there's so many rivets (or other structural components) around that spot that it doesn't matter." I think the last time I was told this was on the fuel tank which -- I'll bet -- few people are measuring the rivet heads through all that pro seal goop.

One of these days, I should bring a gauge to OSH and see what average percentage of rivets are perfectly set.
 
every one

i have put a gague on every rivet i ever set. that said it doesnt mean they passed. i just cant go forward without checking. this is ancient technology :rolleyes: put the rivet in, smash it, and move on. will probally be fine but since we have specs try to go by them. if its over or under its not the end of the world. now a whole row and i ask myself would i bet my life on that row. if i hesitate at all i redo them.. on a side note none are under several are over. :eek: :eek: :rolleyes: :cool: on my next one i will have many half sizes availiable. i really like Little tuna can shop heads :)
 
If you have not Read this "Rivet Strenght test" yet, go do it...

http://www.kilohotel.com/rv8/rvlinks/marvelrivets.html

6 rivets easily held up the MID empty/gross weight of the typical RV 2 seater i.e + 1500 lbs, except grossly unders squeezed rivets.

I also used to check every single rivet, after reading this I relaxed a bit on the gauge, and rather slightly over than under.

Regards
Rudi
 
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No dimensions

Bill Marvel did some good tests, but never qualifies what dimensions "over" and "grossly over" are.

Without these numbers, it is hard to gauge the effectiveness of the tests, which is a pity.

Bill never went from the Mil-Spec tolerances... which probably (my guess only...) would put his visual "over" and "under" within the acceptable tolerances... unfortunately, we will never know.... :(

This is the error of not using go/no go gauges that Rick mentioned in his previous post.... 1.5 x 0.5 is the mid-range of the tolerances, not the only number for "perfect" .. it probably should be called "optimum" or "mid-range"... :)

gil in Tucson
 
Rivet direction

Rivets look good to me, but a comment. Watch installation direction. On the RV-10 VS, the rudder hinge rivets have the mfg'ed head on the hinge side. RV-9? Sometimes it matters, sometimes not.
 
Incredible......

Wow! Incredible rivet test! Thanks, Mr. Marvel.

As we speak though, my Air Tractor(.com) is at the dealer's in Ft. Pierce, Fl. getting another set of wings. The FAA mandated a life of 8000 hours and mine has near 7900 since new, not nearly enough for my usual 325-375 hour summer season.

This rivet test causes me to ask, "What is the guesstimated life expectancy of an RV6,7,8 and-4 that does occasional aerobatics to 3-4 g's and flight in rough air". The speeds which we fly at make the lumpy air harder than it would a Skuzzhawk. Is there even a life? Who might have the highest time RV of any model? :cool: I'm very impressed with Van's engineering and so are a couple of aeronautical engineers who've built RV's and I've transitioned.

Just thoughts.....
 
Thanks again for all the great input from the list. It was all really appreciated and needed as positive reinforcement. I got my rivet guage in the mail and spent some time checking each one.. And now I feel gooood. :D It appears that in my first attempt at rivet squeezing that I hit the money spot on! How true that you need to make sure your eye is calibrated.

Now I am moving onto my first attempts at using the rivet gun this weekend. This I expect will be interesting, though I feel pretty good about what I am striving towards. I should have taken a builder class, but the dates didn't align too well with when I would be available. As such Im taking my years of car/motorcycle mechanic skills coupled with the enormous amount of model planes I built and flew growing up, to make this happen.

If theres anyone in the Seattle area thats riveting this weekend and wants to give me a short demo I would be incredibly grateful! If not, all good. I think with the sites out there and this list I can pull it off.

Thanks again!!

Cheers,
Josh
 
riveting

Way to go Joshua! :>) Every now and then a topic comes up that stirs up the hornet's nest and this appears to be one of those topics.

When this many people reply, you get to view all kinds of opinions and facts and theories. It is absolutely wonderful.

As for your rivets - I LIKE 'EM - but I'm not a Tech Rep. The Tech Rep is the one that will have to be happy with your work.

If you don't know one - find one. His experience will be invaluable now and later.
 
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