[JimMac]

The RV-12 instructions for assembing the roll bar states to machine counter-sink the top roll bar rivet holes for CS4-4 rivets. No mention is made about this counter-sink being 100 deg or 120 deg. Should I ALWAYS use 120 deg for CS-4 rivets? I remember some places in the wing construction where it DID specify 120 deg for the counter-sink for some CS4 rivets.
Thanks in advance for any help.
JimMac

 

[JanRV6UK]

flush pop rivets .. like the CS4-4 are 120deg ...

 

[bhassel]

I made a mistake in the emp where I used 100 degree versus the 120 degree for the CS-4s. I got a little worried and contacted the factory. They stated 'CS-4s always need a 120 degree countersink'.

In my case, at that point, for what I was doing, (any more prepositions I can fit in there?) it was mostly a cosmetic concern. I bought a full countersink set to use on the remainder.

Bob

 

[DaveWelch]

120 degree C-sink

The RV-12 instructions for assembing the roll bar states to machine counter-sink the top roll bar rivet holes for CS4-4 rivets. No mention is made about this counter-sink being 100 deg or 120 deg. Should I ALWAYS use 120 deg for CS-4 rivets? I remember some places in the wing construction where it DID specify 120 deg for the counter-sink for some CS4 rivets.
Thanks in advance for any help.
JimMac

Jim, I've got one you can borrow while waiting for yours. Send me a PM if interested. Good excuse to meet up at last!
Dave