To countersink or not to countersink.....

[HighSchoolBuilders]

Hi everyone!

I am working on my RV-8 Fuse...

The instruction (Pg. 8-31, Para 4) wants me to Machine Countersink the F-802D-L-1 & R-1, to accept dimples #19 screw hole on the F-820L-1 & R-1 side skin. I find the F-802D-L-1/R-1 is too thin to be machine countersink for #19 dimple, but too thick to be dimpled. I can't countersink as per the instruction without enlarging the hole.

Hope someone can answer this...thanks!
Hank

[bird]

Cleco the 802s spacers and 802d box plates to weldments and bulkheads, then machine countersink the screw holes in 802d. The spacers behind it will keep the countersink centered and make a good countersink. Directions tell you to cleco them that way back on pg.8-17 4th paragraph down. I think it also says to machine counter sink with them installed on the airframe too but can't find it right now, it may be on the dwg itself. happy building!

bird

[HighSchoolBuilders]

Thanks Bird! I wasn't sure if I am suppose to countersink the hole bigger than the pilot hole, but if the manual says so, it's good to go, thanks!