Acceptable pulled rivets

[Murray Parr]

I have just completed the rudder drive horn assembly on my Waiex B and noticed the cherry rivets have pulled nicely but the mandrels are all cut off deep inside the rivets. I thought the mandrels are meant to be close to flush. The mandrel is also rattling around loose inside the pulled side of some of the rivets. Can anyone tell me if this is normal? or how I can change this? I have a Taylor pneumatic rivet puller from Cleveland tools

Thanks

Murray

[NWade]

Murray -

What you've described sounds perfectly normal; no need to fret! :-)

Here's generally what you're looking for after you pull a rivet:

• The head is nice and flush and tight against the material
• All of your materials are tightly sandwiched together, with no gaps between them.
• The tail of the rivet has swollen to a larger diameter than the hole size
• The swollen tail is swollen all the way up against the material you are riveting (i.e. the rivet didn't stop pulling early)
• The mandrel broke off somewhere below the level of the rivet head, and didn't leave a big spike of stem sticking out (as this may indicate the rivet pulled all the way through the material and broke only when the mandrel hit the back side of the head).

Hope this helps, and good luck with your build!

--Noel
Sonex #1339, Center-stick, TD, Acro-ailerons, Turbo AeroVee
Wings & Empennage complete, fuselage done through F09

[n982sx]

In addition to what Noel said, yes the mandrels can be loose inside. When I built my first flap and shook it, it sounded like a giant maraca!

Cherry Max rivets and some others indicate the rivet is properly pulled when the stem breaks flush. Those rivets also capture the mandrel tightly. The Sonex rivets are different.

[Murray Parr]

Thanks Noel and Bob

[kmacht]

To add a little more to the last post the sonex uses Avex rivets not cherry max.

Keith
#554