Flap/aileron trailing edges

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Meatball
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Flap/aileron trailing edges

Post by Meatball »

Anyone have any hints on the rivets here? I countersunk them but I have 2 or 3 that are sitting proud of the surface. I’m wondering if the structure underneath is keeping them from seating all the way...

Suggestions?

Thanks!
~Rob
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danerazz
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Re: Flap/aileron trailing edges

Post by danerazz »

Highlander or SS? I’m not familiar with the SS, but if it is like the Highlander, the folded trailing edge material is pretty tight. You have to keep the rivets toward the front of the folded part, and also stagger the side of the rib that the top and bottom rivets are on. This keeps the rivets from hitting the opposite side of the folded part (top to bottom), and staggered sides keeps the top rivet tails from hitting the bottom river tails.

Beyond that, always test fit your counter sinks before setting the rivets, and make sure you press straight and continuously while you squeeze, or the rivet can set high. Also, it is not uncommon to have the remaining stem break off proud, necessitating a dremel grinding of it.

Lastly, make sure you are using the correct countersink angle (120 degree for cherry pop rivets, 100 degree for solid aluminum rivets).
Dane

Paralysis by analysis
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Meatball
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Re: Flap/aileron trailing edges

Post by Meatball »

Highlander...

Thanks for the info! It's not intuitive for sure.

But how do I know if they are Cherry pop rivets or solid aluminum? Are you saying all the pop rivets in the kit are Cherry pop rivets and the ones you need to squeeze or use the bucking bar are the "solid" type?
~Rob
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danerazz
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Re: Flap/aileron trailing edges

Post by danerazz »

Yes. If they are “pop” rivets, they are cherry-type 120 degree flush (CCC-#). If they are literally a solid pice of aluminum that you buck or squeeze, they are 100 degree solid -A or -AD rivets. I believe everything in the kit is a cherry-type pulled rivet, either aluminum or stainless, and either flush or countersunk. I don’t believe (though can’t remember) there are any solid rivets in the kit. I used a bunch, but that was due to mods for my boot cowl and other areas.

FYI: Cherry is a line of rivets made by Avdel, but many places sell what amounts to a “cherry equivalent.” These “imitations” should be functionally identical as well as have the same strength as the Avdel rivets, but I have noticed some of them don’t break the mandrel as clean below the surface of the rivet, leaving a jagged little nub that needs to be filed off after pulling if you want a truly flush and clean surface.

Aircraft Spruce carries a ton of lengths and different material (aluminum, stainless, monel) in both flush and protruding heads, in a couple different diameters if you need a different length or more.

You can NEVER have enough CCP-42s, and make sure your metal stack that you are riveting falls within the grip range. Lots of good info on the ‘Spruce website about the rivets.

I bought a lot of different extras, used 3x more than I probably should have, and have a lot of left over rivets, but I use them for everything around the house and shop.

If you need “special” rivets (or any other of all size fastener), McMaster Carr is great, as long as you need 100 of them!

Hardware is great!
Dane

Paralysis by analysis
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Meatball
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Re: Flap/aileron trailing edges

Post by Meatball »

Perfect! Thanks Dane. Looks like I'll be shaving those rivets off and starting over...
~Rob
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FlyerChief
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Re: Flap/aileron trailing edges

Post by FlyerChief »

Make sure the holes you drill for the rivets are deep enough for the rivet to go all the way in, especially when they are into the Hysol on the trailing edge. Also make sure they are all the way in before starting the squeeze. If they are up in the slightest, the rivet grabs the Hysol and prevents you from being able to get the head to squeeze flush with the surface.
You may also find it very handy to make a tool like this to ensure the trailing edge is exactly the right distance from the 1" spars in the flaps and ailerons. Simply place it along side each rib as you rivet in the trailing edge aluminum. I just used a squeeze clamp to get the aluminum in tight enough to fit into the tool before riveting.
Aileron and Flap trailing edges.jpg
Regards,
Dan
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When everything seems to be going against you, remember that the airplane takes off against the wind, not with it. ~Henry Ford
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SheepdogRD
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Re: Flap/aileron trailing edges

Post by SheepdogRD »

Meatball wrote:Looks like I'll be shaving those rivets off and starting over...
Well, wait a second. You've already installed them with epoxy, right? Drilling them out takes really careful technique so you don't make a hole too big. Reinstalling the rivets in an already-epoxied joint probably won't make the joints "better" unless the offending rivets are seriously wonky. If the only issue is a little of the rivet heads protruding, there's no strength problem. You might simply leave them in place and Dremel or file them off level with the trailing edge material. That area will all be covered with fabric, anyway.
Richard Holtz
Highlander N570L -- Ms. Tonka -- in gestation

If just enough is really good, then too much ought to be perfect.
Meatball
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Re: Flap/aileron trailing edges

Post by Meatball »

FlyerChief wrote:Make sure the holes you drill for the rivets are deep enough for the rivet to go all the way in, especially when they are into the Hysol on the trailing edge. Also make sure they are all the way in before starting the squeeze. If they are up in the slightest, the rivet grabs the Hysol and prevents you from being able to get the head to squeeze flush with the surface.
You may also find it very handy to make a tool like this to ensure the trailing edge is exactly the right distance from the 1" spars in the flaps and ailerons. Simply place it along side each rib as you rivet in the trailing edge aluminum. I just used a squeeze clamp to get the aluminum in tight enough to fit into the tool before riveting.
Aileron and Flap trailing edges.jpg
Regards,
Dan
Thanks, Dan! Good info there and I'll take a gander to be sure what exactly I'm looking at.
SheepdogRD wrote:
Meatball wrote:Looks like I'll be shaving those rivets off and starting over...
Well, wait a second. You've already installed them with epoxy, right? Drilling them out takes really careful technique so you don't make a hole too big. Reinstalling the rivets in an already-epoxied joint probably won't make the joints "better" unless the offending rivets are seriously wonky. If the only issue is a little of the rivet heads protruding, there's no strength problem. You might simply leave them in place and Dremel or file them off level with the trailing edge material. That area will all be covered with fabric, anyway.
As always, Mr. Sheepdog, thank you! That is question I had. If they've already been pulled and set in the epoxy, will it really make a difference at this point if I just grind the heads. I can't imagine any structural strength will be lost, but I'm not an engineer so I have no idea.
~Rob
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danerazz
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Re: Flap/aileron trailing edges

Post by danerazz »

Don’t overthink it. As long as the rivets are there, just shave the heads. If you start drilling them out you risk buggering out the holes and making the next set of rivets fit even worse, or loose, or both.

Just make sure the TE is attached, it’s not like they are holding the wings on.
Dane

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Tralika
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Re: Flap/aileron trailing edges

Post by Tralika »

danerazz wrote:Don’t overthink it. As long as the rivets are there, just shave the heads. If you start drilling them out you risk buggering out the holes and making the next set of rivets fit even worse, or loose, or both.

Just make sure the TE is attached, it’s not like they are holding the wings on.
I agree. Also keep in mind that the shrunk fabric will add the strength and rigidity of the structure.
John Nealon
Wasilla, Alaska
Highlander Extreme #191
mykitlog.com/jnealon
Meatball
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Re: Flap/aileron trailing edges

Post by Meatball »

You guys are awesome! Thanks so much!
~Rob
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BucF16
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Re: Flap/aileron trailing edges

Post by BucF16 »

The rivets are there only to the the TE in place till the HYSOL is dry. I had sone sit proud and shaved them off with the dermil.

Good Luck
Bruce Johnson Highlander # 393
"Because I fly, I envy no man on Earth"
Builder web site:
http://www.bruceshighlander.blogspot.com
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danerazz
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Re: Flap/aileron trailing edges

Post by danerazz »

BucF16 wrote: I had sone sit proud and shaved them off with the dermil.

Good Luck
You drinking’ tonight? :mrgreen:
Dane

Paralysis by analysis
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SheepdogRD
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Re: Flap/aileron trailing edges

Post by SheepdogRD »

danerazz wrote:You drinking’ tonight? :mrgreen:
Nope. The evil spellchecker is his worst enema.
Richard Holtz
Highlander N570L -- Ms. Tonka -- in gestation

If just enough is really good, then too much ought to be perfect.
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BucF16
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Re: Flap/aileron trailing edges

Post by BucF16 »

danerazz wrote:
BucF16 wrote: I had sone sit proud and shaved them off with the dermil.

Good Luck
You drinking’ tonight? :mrgreen:
No, I wasn't then. But I am now :twisted:

Dane, You know me, I never proofread my posts. 8)
Bruce Johnson Highlander # 393
"Because I fly, I envy no man on Earth"
Builder web site:
http://www.bruceshighlander.blogspot.com
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