Cherry Max Rivets in Gear Towers

Hello Everyone,

I was reading an old post that had a link to Jim Daniel's builder's log. He wrote that Van's had advised against putting 1/8" Cherry Max rivets through the longerons at the top of the gear towers. My technical counselor and I were putting in rivets there recently and had a h*** of a time bucking solid rivets along the longeron inside the gear tower. I ended up installing Cherry Max rivets in that spot, but I'm a little worried after reading the earlier post.

Have any of you with flying RV-8s installed Cherry Max rivets there and had any problems? I haven't read about anyone's 8 falling apart yet for that particular reason.

As always, your input is appreciated.

I used a couple in that area and didn't have any problems with them.

http://blog.bowenaero.com/?p=43

not flying yet, but not worried

I used about 6 or 8 cherry-max on each side across the gear towers and at the corner (motor mount prevented bucking solid rivet at corner).

I'm perfectly comfortable with the outcome. They are likely stronger than a 3/32 solid rivet, and there is plenty of edge clearance.

Cheri-max

I have mine set-up to do this when I get there. I have a buddy who did this on his 8 and I have read where many have. They are structural and I personally am not worried (that doesn't mean it's all okay either). Look on the airliners and they have all kinds of cherry-max rivets on structural fixes where they couldn't buck the fix. Good enough for them......good enough for me.

Another vote for the Cheri's in this location - almost 1000 hours of flying on my -8, and no apparent problems. Cheri's are legal substitutes for just about any solid rivet in a location, and as long as you don't do somehthng silly like build an entire airplane out of pop rivets, you should be ok....Oh wait a minute, there is that pesky RV-12....

Paul

Cherry Vs Solid!

It was this group that got me into making some smaller packages of Cherry max. Specifically the CR3214 Reduced head countersunk version.

They have been accepted very well and purchased by many listers.

Properly prepped and installed, these should work well.

They still need a nice clean hole and countersink of the correct dimensions, but at this point in the project if you cant create that condition you probably shouldn't fly or drive.

They do need to be inspected head and tail to verify that the procedure went correctly.

They will not withstand an extreme overload, but neither will the solid rivets.

BTW, we now have over 100 more Cherry part#'s in small packages, Doug and Listers thanks for the launch on that idea.

Start Here and then select your size and style.
http://www.gen-aircraft-hardware.com/store.asp?alternate=CR3214-4-02+PKG%2F10

For tech page http://www.gen-aircraft-hardware.com/images/pdf/cherry.pdf

Have Fun!

Thanks Everyone.

I'll inspect the shop head side and relax. I'm getting ready to move the fuselage out to the paint shop this week, then on to the hangar. Hope to be flying by the end of the year!

What length did everyone use in that area? -3 or -4?

I think the rivets I used were CR3212-4-4.

A Cherry Max rivet is an approved substatue for solid AN426 and AN470 rivets according to the FAA. Just make sure that when they are pulled the locking collar has set correctly and you are good to go.

During your condition inspections, if the heads of the rivets are visable, just do a quick recon to make sure the locking collar has not somehow come loose and the stem is still installed. A Cherry Max will loose its strentgh if the stem is not in the rivet.