Fuel Tank page 37-02

page 37-02 step 7, machine countersink the lower row of #30 holes. The plans call for AK-42H rivits. Do these holes get a 120 deg. countersink?

Mark, did you get this resolved? I'm soon starting this section and I'd like to know for sure what to do with these holes.

Yes, evidently all or most all countersunk pop rivets are 120 deg.

RV-12, pages 37-02 and 37-03

I am current researching the countersink for the AK-42H and CR3212-4-4 rivets. These rivets are used in the FWD Tank Bracket T-1205. See pages 37-02 and 37-03.

A goggle search found:
The CR3213-4-4 rivets are 100 degrees
The AK-42H both 100 and 120 degrees were specified depending on the web site

Measuring the rivet drawing in chapter 5, indicated that both are 100 degrees. The only pulled rivet shown in chapter 5 with 120 degrees is CS4-4.

Anybody know the teal answer?

Thanks, Dave

I emailed Van's about this a long time ago, and sent in a picture of what I thought the CS specs should be.



I CS'd 100 degrees for the 7 cherries and 120 for the others. This should be the real answer and that's what I did, but I don't think the plans were changed. Perhaps in actual practice it doesn't matter?

Thanks Tony,

I went out to the hanger and measured the rivets.

What I found agrees with you.

CR-3212 measured 100 degrees

AK-42H measured 120 degrees

Additionally
AACQ-4-4 measured 120 degrees
Cs4-4 measured 120 degrees (to check measuring technique)

-Dave