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How do these rivets look?

ColoradoSolar

Well Known Member
I am working on the first part of the practice kit and I would like to get some feedback on how my rivets look. I apologize that the depth of field is so shallow and some of the photos are a bit out of focus.
 

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I did check them with the rivet gauge and they all just barely fit or were just slightly too big to fit. The shop head on the 3/32 rivets were around 0.140 to 0.146 in diameter.
 
They look very unspectacular. In other words they look perfectly fine.

In addition to checking the diameter of the shop head you should also check the height. You want to make sure the rivet is not flattened out too much. The rivet gauge you have should have a way to check the height.
 
How do I check the height on a dimpled skin? My rivet gauge has one end that can be used to check the height but I am not sure how to use it when the parts are dimpled.
 
drill bit

An easy way to check the height of a shop head for a dimpled rivet, or any rivet really, is to hold the end of a drill bit of the right diameter e.g. 3/64" alongside the shop head.
Later on when you are riveting in confined spaces, like when closing up the wings, you will be able to check a shop head by feel.
 
On the second picture, there's a gap on between the two parts on the left hand side. This was likely caused by not enough clecos/clamps/whatever before riveting, so that instead of drawing the parts together, the rivet swells a little bit in between them.

On real airplane parts, you shouldn't be able to slide a .002" feeler gauge into that gap all the way to the rivet shank.

It seems like they might be a little over driven, but a gauge should tell you for sure.

I'd encourage you to read MIL-R-47196A and print off a copy to keep in your shop. All will be made clear. It's the mil-spec that deals with the kinds of questions your asking. I believe that Vans even links to it in the support section of their web site.
 
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How do I check the height on a dimpled skin? My rivet gauge has one end that can be used to check the height but I am not sure how to use it when the parts are dimpled.

Measure to the hole in the dimple. i.e. if it was a volcano, you're measuring the rim, not to the field below the mountain.
 
Rivets and dimples

They look fine to me.
As others mentioned; find the rivet spec table and print it.

I like to use a modified guage. I drill a hole for minimum diameter. If the shop head fits the minimum hole, it needs more. If it fits the ideal hole, it's perfect. That should be 1.5D. Thickness is tricky. You'll find a method that works for you. Easy to fab a home made thickness tool for a dimpled surface.

Friendly suggestion...
The flat piece appears to be under dimpled. Whichever tool you use, work on the set up.
Hold the part so a reflection of a straight line intersects the holes. Something like a door frame or a garage frame. The reflection line should be perfectly straight. No distortion. Now is the time to get the technique nailed down. I don't think under dimpled is a structural problem but it's very noticible on a wing or side skin.
 
The next skill to learn is rivet removal. The third skill to learn will be how to get rivets back in to holes that are now bigger from the original rivet or your drilling technique.

So once built take the practice kit appart.
 
The next skill to learn is rivet removal. The third skill to learn will be how to get rivets back in to holes that are now bigger from the original rivet or your drilling technique.

So once built take the practice kit appart.

Already been practicing some removal. My first riveting was actually my 6A's panel upgrade. I figured the panel was non-structural so couldn't hurt anything too bad :)
 
Friendly suggestion...
The flat piece appears to be under dimpled. Whichever tool you use, work on the set up.
Hold the part so a reflection of a straight line intersects the holes. Something like a door frame or a garage frame. The reflection line should be perfectly straight. No distortion. Now is the time to get the technique nailed down. I don't think under dimpled is a structural problem but it's very noticible on a wing or side skin.

I did look at the reflection before I riveted it together and I thought the reflection looked ok but I will dimple another piece and see what the reflection looks like.
 
@ColoradoSolar if those of are some of your first few rivets, you work is excellent. It will just continue to get better, faster and easier after you set a couple thousand of them. I wish every rivet on my plane looked as good as those.
 
That's acceptable, but near the bigger end of acceptable diameter. Conventional wisdom is you want between 1.3D and 1.5D. So on a 3/32 (.093") rivet you should be between .121" and .140".

You really should get a copy of "Standard Aircraft Handboook for Mechanics and Technicians", it has all this info in it. It lists the Minimum and maximum upset diameter as 1/8" (.125") and 5/32" (.156")

Naturally, you also need to maintain the minimum height. If your diameters are good but your height short, you need to start with a longer rivet. The rivet call outs in the plans are not always correct.

I did check them with the rivet gauge and they all just barely fit or were just slightly too big to fit. The shop head on the 3/32 rivets were around 0.140 to 0.146 in diameter.
 
How do I check the height on a dimpled skin? My rivet gauge has one end that can be used to check the height but I am not sure how to use it when the parts are dimpled.

It is tricky, I eventually used a process of elimination. If rivet length before driving is ok (much easier to measure), hole is not oversized, and the diameter after driving is ok, then the height will be fine.
 
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