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Drilling out a CherryMax rivet

SabreFlyr

Well Known Member
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Drilled out a rivet in the rear spar and flap gap seal. The tail fractured when I squeezed it. Because of the restricted access, decided to replace it with a CR3212-4-2 (I know, that hole wasn't supposed to be dimpled/countersunk but I got carried away :rolleyes:). Unfortunately, I had trouble with this one, as well, and I need to remove it, too. I suspect it will spin on me when I try to drill it out, particularly considering that the shank hasn't been fully expanded. Somewhere, I've seen a tool for drilling out pulled rivets that holds the head of the rivet from spinning while it's being drilled. Can anyone tell me where I can find one?
 

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I think there are some videos on the CherryMax removal.

I used this on several with success.

The reason for my skill expansion was this - when pulling the CMax with a standard puller (I have a marson) I learned not to fully open the tool and only pull the first 1/3 or so of the stroke, then open it fully and pull steadily to success. The stroke was typically just short of the happy snap then when resetting the tool the pull shaft failed in the wrong place. "pre-setting" the rivet then making the full pull was much more successful.

Good luck. Practice where it is easy or not important

Why not install a solid rivet?
 
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Why not install a solid rivet?

When I get this one out, I may try a solid rivet again. I felt that the squeezer had slipped on the tail of the previous rivet because of the awkward access between the rib and the aileron hinge bracket doubler. However, I didn’t have any trouble with the corresponding rivet on the other wing.
 
I think there are some videos on the CherryMax removal.

Ahh, the first video’s technique won’t work in this case because it’s a flush head (wasn’t supposed to be but, as I said, I got carried away with the countersinking). None of them address the issue of the rivet spinning in the hole while trying to drill it out.
 
I have a special tool for removing pulled rivets - I think it came from ATS. It sorta works in some situations, works well in others, and failed in others. One to have in the box, but not a 100% answer.

Check their site if you want to see it.

Paul
 
Dremel and a small ( less than 1/8" ) corse carbide bur will make short work of it. Don't get greedy and mess up the hole, grind on it a little and wiggle it with needle nose pliers , repeat as needed. A little " Tap Magic " brand tapping fluid will help greatly to keep the bur from loading up , slow speed to keep the heat down or the aluminum melt to the bur.
 
Make sure you tap out the mandrel before you try to drill it, or the drill will wander off the center into the soft aluminum. The tool you describe is marginal at best in my opinion. I think it’s designed to help you center the hole more than holding the rivet from spinning. You only need to drill off the head, and it should pop out the back. If it’s still spinning, try to hold the back with a small vice grip, and drill the head in increments (after knocking out the mandrel. As for setting a solid 426 rivet, you could use a bucking bar on the flush head, and a “back rivet set” on the shop head.
 
I have a special tool for removing pulled rivets - I think it came from ATS. It sorta works in some situations, works well in others, and failed in others. One to have in the box, but not a 100% answer.

Check their site if you want to see it.

Paul

Thanks, Paul! Finally found it: https://aircraft-tool.com/shop/detail.aspx?id=1341S-BLUE

Looks to be the same as my other rivet removal tool with different nose pieces. I’ll have to see if I can just buy those.

BTW, LOVED the book, particularly the early instructional chapters that I didn’t anticipate and thoroughly enjoyed. Also, enjoyed and completely agree with your treatise on leadership vs management. Too much of the latter and not enough of the former around today!
 
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