Finally

[geraldmorrissey]

Installed the final rib attach angle on the left rear spar this morning. The spar fab portion of this project is complete. Time to break it down and paint it while the humidity here in Seattle is still low. I can't believe its finally done. I'm glad I did it, but I'll never do it again. The final assembly should be fun. My scrap pile is huge. Pics to follow.
Gerry
Patrol Patrom #30

[AZBearhawk272]

Congratulations! The spars are a big milestone. When they are done they are impressively significant.

Kevin D
#272

[Bcone1381]

I have one (two part) question for you Garold. When you break down the spars to paint, you will have numerous spacer bars and rib attach angles. Did you fabricate them so they are all identical and interchangeable or were they match drilled individually at there respective locations making each one special? And if each one is special, how will you keep track of where each goes after they are painted?

[geraldmorrissey]

On the fwd spar, I had a professional machined all the spacer bars at the same time to the same length. On the rear spar I made the spacer bars individually but hand filed them to 3.875 + .002/-.000. All the rib attach angles for both fwd and rear spars were made individually. All the spacer bars and rib attach angles for the front and rear spars at each rib station were drilled individually (however the forward and aft spacer bars at each rib station were drilled as matched pairs before installation on the spar webs) so in theory, no two spacer bar pairs or attach angle pairs at different rib stations are interchangeable though many probably are. All are very close, as I laid the holes out and drilled as close as my eyes and equipment would allow (with help from a lot of light and an array of magnifiers and cheater glasses). As far as detail part ID, that was a tricky one. I put alot of thought into it and here is what I came up with. I bought a box of paper tags with attach strings from Office Depot. On spacer bars I ran the tag string through the upper attach hole with the printing on the same side of the tag as the non fay surface of the spacer bar. I ID'd with " #1LR UPR NF". First spacer bar, left rear spar, upper attach hole, non fay surface (the surface that does not come in contact with the spar web). On rib attach angles I ID'd with " #1LF UPR FFO". First angle, left front spar, upper attach hole, fay flange outboard (or inboard). The fay flange is the flange that contacts the capstrips and the spacer bars. The fay flange points either inboard or outboard. Finally I covered the paper tags with clear packing tape as the primer obscures the printing. So I think I accounted for clocking of all the parts. I start priming the last spar this weekend, then assembly. We'll see if my system works to locate the scores of detail parts.
Gerry
Patrol Tandem #30

[geraldmorrissey]

One ID item I forgot was that I also added which side of the spar the spacer bar or attach angle attaches to. So for spacer bars "#1LRA UPR NF". Rib locatuon #1, left rear spar, aft side of the web, upper attach hole, non fay surface. Same thing for attach angles.
Gerry
Patrol Tandem #30

[davzLSA]

Congratulations Gerald, I consider the scrap pile the education pile and the cost of learning. Great accomplishment, you will have fun doing the final assembly.