Tank Z-Bracket Layout

Don't want to bring this up yet again, but doing my research on the Tank Z-Brackets, there is one little bit of info that I wasn't clear on.

Using the Hurlbut/D.C method. Does a person locate the initial 1/8" diameter hole dead center in that exposed top side of flange? or does a person measure center on the bottom side (Where the bracket face meets the spar) I see that some say that their socket clearance requires that it moved outward 1/16" off center.

It seems the process was better described a number of years ago but that information now seems to be getting tough to find.

What proved to be the best way of placing the initial hole.

Holes

I centered mine but I have a set of thin wall 1/4 drive sockets.

I followed Jason Beaver's build site (he used what used to be known as the "Checkoway" method before Dan corrected us). Here's a paragraph from by build log:

I started out by positioning the center bolt hole on one flange of each z-bracket. This hole on the most inboard bracket is located 1/16" AWAY from the flange centerline to allow a socket to be used to torque the bolts for final installation. The other 6 z-brackets have this hole located 1/16" TOWARD the flange, which has the effect of moving the rivet holes that much farther from the bracket web to allow more room for use of a rivet puller when attaching the tank baffles.

It worked great. If I ever build another set of tanks, I'll do it the same way.

I just finished my z brackets after heavy reading. Miles' site is great. I also referenced these two:

http://www.rv7-factory.com/?p=1333
http://rv-7construction.com/2010/09/11/started-fuel-tank-z-brackets-91110/

There are seven brackets on each wing. I numbered the bracket closest to the fuselage 1 and farthest from the fuselage 7. On bracket number 1 I drilled 4/16" from the bracket edge. On brackets 2 through 6 I drilled 5/16" from the edge. Everything looked great when I lined up the tank with leading edge and match drilled z brackets to baffles.

Fair warning - I haven't pop riveted the tanks in place yet, so the whole plan may fall apart.

Bob
2016 Dues Paid

Ahh ok. I'm getting it

The pieces are starting to fall together. So if I did follow the 1/16" offset way of doing things. You would find the exact center of the flange (as viewed from the aft of the bracket). This was the part that I was scratching my head over.

Like this then, correct??

Garet, your drawing shows exactly what I did: offset from the centerline as measured on the outside of the flange.

Thanks

Awesome!! Thanks for the input guys. It was throwing me off looking at the construction logs as some have drawn the center lines on different faces of the flange.

P.S. Go Broncos!

What to check for:

Most of the fasteners screw in from the bottom side, the most inboard Z bracket fastens from the top. There is a close tolerance when placing a socket on with the vertical side of the z bracket. You can check this tolerance by placing a socket where the fastener will be to ensure that the socket will fit. You can also use a washer of equivalent diameter to the socket to find the required clearance and hole center.

Great Diagram Aero!

I'm just getting ready to do this; you've cleared it up for me...