This is a picture of the wing leading edge and the W-423 joint plate.  The joint plate is fabricated out of strip of aluminum labeled as AS3-032x1.5x36.5. 

On the leading edge side, Van's has you draw a line 1/2" from the edge of the joint plate to align with the rivet holes on the leading edge side.  As you can see in the picture below, my sharpie marker line looks to be centered in the leading edge rivet holes.  This arrangement should then leave 11/16" from the edge of the W-408R rib so that the fuel tank can be attached via plate nuts later.

My alignment here looks pretty good.  The trick, however, is to get the joint plate properly lined.  It took me around a half dozen tries to get it to a point where I was happy with it.  I did try to pre-form the aluminum strip by bending it around the end rib and that helped.   Ensure that you have adequate hole clearance on the aluminum strip at the aft side of the rib on both the top and bottom. 

As you try to position the joint plate between the rib and the leading edge skin, it becomes very hard to move and align as it is a very tight fit.  I did have to lightly tap with a soft faced mallet in order to get everything positioned.  This is just a trial and error effort to get everything straight the way you want it.

FABRICATING FUEL TANK Z-BRACKETS

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Disclaimer-  I tried Van's method and didn't like my results.  This log entry and my next log entry detail my experience with this task.  The method I tried the second time around worked great for me, however, I can foresee if not done carefully and correctly, you will have a hard time riveting the fuel tank rear baffle / ribs to the Z-Brackets.   If misdrilled by a little bit, you won't have adequate clearance between the Z-Bracket flange and web to rivet everything together (the same goes for Van's method to).  I am not endorsing one method or another.  I am just detailing how I got through trying to get all these pieces to line up correctly.  Read at your own risk!

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Okay, the rest of this page is all about what I did the first time I tried fabricating the fuel tank Z-Brackets.  In my opinion, Van's instructions are not the best for this task.  I started by following Van's instructions and now I am ordering a new set of Z-Brackets for the left wing.  No biggie, I checked the price on their web site.  Van's gets a whopping $1.60 for another set.  I am more disappointed in how much time I ended up wasting.  I guess I am too picky.

Anyway, Van's has you draw centerlines on the flanges for the Z-Bracket and mark the exact center of those lines.

• The flange that will be bolted to the main spar is drilled to size #12.
• The flange that will be connected to the T-702 tank baffle is drilled to 1/8".

OKAY, HERE IS WHERE VAN'S INSTRUCTIONS START BECOME A PROBLEM.  Do not drill the 1/8" hole on the flange (where the red "x" is located) on any of the Z-Bracket flanges.

Let's focus on this log entry why their instructions don't work that well for me.  When I was trying to figure this assembly was going to fit together, I had a hard time picturing the end result for some reason.

If you are not careful where you put your hand while drilling>>>  Be prepared to invent new 4-letter words (multiple words).  Your hand is not a good substitute for a vice clamp, cleco clamp, or a scrap AN3-4A bolt. My hand could not get out of the way of the drill fast enough.  It should be noted that the hole in the Z-Bracket looked great.  To bad I was going down the wrong path and would have to rework the Z-Brackets the next day. 

Aahhaa, trying to out-smart the Z-Bracket, I used some large jaw vice grip clamps, I was able to better stabilize the Z-Bracket so that I could drill the remaining #12 holes.  This actually worked a lot better than my hand.

Just an picture of the clamping arrangement on the aft side of the spar.

After I drilled and bolted the Z-Brackets to the main spar, it became so clear why Van's instructions didn't work very well.  Van's has you drill the 1/8" hole in the Z-Bracket which theoretically is where you will cleco the tank baffle to the Z-Bracket and final drill the remaining rib / baffle / bracket holes to #30.

Well, as soon as I tried to line up the holes between the tank baffle and the Z-Brackets is the moment I realized I just spent a couple of hours on getting nowhere.  I had read other builders state that Van's instructions where not very good here and discounted that information.  I always try to give Van's the benefit of the doubt.  Most of the time they are right.  OOPS, didn't pay off this time!!!

The problem, was that without having access to precision milling equipment, I could not drill my holes to the exacting tolerances Van's does with their pre-punching's.  When I tried to line up the Z-Bracket to tank baffle holes, I could only get one or two holes to line up at a time.  Not to mention that when those holes would line up, there was as much as 1/8" to 1/16" left or right movement in the tank baffle to get that alignment.  Van's instructions tell you to elongate the holes in the baffle as necessary to allow the baffle holes align with the T-701 (tank skin) when the T-701 is clecoed to the spar.  (I did not like the elongate holes idea).  Again, I am to picky...  For my efforts, I was going to have to elongate 7 holes on the tank baffle to get proper alignment with respect to the tank baffle, spar, and leading edge.

• Red Arrow(s)-  Approximate illustration of where the Z-Bracket and the rows of tank baffle plate holes are.
• Yellow Arrow-  Illustrating that using Van's instructions, you may have to move the tank baffle or elongate the holes in the tank baffle to get ANY of the 1/8" holes to line up.

Okay, time to call it a day and come up with a better strategy.  I will work on this tomorrow.