Lightening hole size in ribs ?

[fairchild]

The big round holes in the middle of the ribs--- they are drawn in on the plan's rib sheet. The diameters on the plan--- are they the diameter before or after bending the
edges down ? ( I am guessing before--)

Am i correct the circle on the plans is the where you cut the aluminum rib blank (as opposed to the edge of the flange bend) ?
Seems a little vague there.....
Tim

[marcusofcotton]

Correct x2, enjoy!

[Chris In Milwaukee]

Indeed, before flanging. Either way, it doesn't matter much. If the measurements were post-flanging, then the ribs would weigh a fraction more because there's more metal in them. But that's just nit-picking. Have fun!

[fairchild]

Thanks-- those holes just look kind of scarey big on the drawing. like there wont be much rib left ! :-)
Seems like Bob's "flow" of information is suited to match the logical steps used to fabricate (so far---)
Im just trying to keep up here ... :-)

Thanks
Tim