Part 5: Installing the "Upgrade Package" to our Zodiac CH 601 XL: Riveting the Spar Extrusion Angle

After having drilled out the rivets, we now cut out the original Top Spar Cap Angle (6W3-6) 1680 mm. from the inboard end to replace it with the 1/8-inch extruded angle 6-ZU-1-1, taking care not to cut into the rear upper spar cap (we leave the front upper spar doubler (cap 6W3-2) and the rear upper spar cap (6W3-2) intact):

We position and clamp the new Extrusion Angle (6-ZU-1-1) next to the original Rear Upper Spar Cap (6W3-4):

The video clip below shows more detail on this - we had to trim the top rear rib corners slightly to clear the new Extrusion Angles. Here, Roger back-drills the original spar cap angle to the new Extrusion Angle and then clecos it back into the wing assembly for riveting:

Next, we rivet the spar assembly back together with the new Extrusion Angle:

The riveted assembly: On the left is the new Extrusion Angle, with the original Spar Top Cap Angle on the right:

Here's the video clip showing the installation of the Extrusion Angle:

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Comment by Timothy R Mix on December 4, 2009 at 1:25am
Also I am getting ready to help a gentlemen out on his repair so if anyone needing help in the Northwest region (Northern Cali, Oregon, Washington, Idaho, Neveda) with doing this I will help you. I am an A&P IA and have been prcaticing sheetmetal for quite some time and have all the require tools and skills to do this. I will be jobless come the first of the year and will be willing to come to you or you can come to me. Just call me at 541.399.2731
Comment by Timothy R Mix on December 4, 2009 at 1:21am
Carlos, Yes I saw that too. That cap either should be entirely replaced or it needs a proper splice reapair. I would vote for entire replacement myself.
Comment by Carlos Sa on November 16, 2009 at 2:04pm
Sebastien, aren't we introducing a weak point at 1680?
There is a discontinuity between the Extrusion Angle and what remains from the original Spar Top Cap Angle...
Comment by Greg P Couttie on November 16, 2009 at 12:33pm
On my 2008 Xl kit the solid rivets are installed from the rear not on the front as in this older demo aircraft,it might
not be as easy to see where your drilling as the spar sap angle "LIP" is in the way,also I can see that you have removed 1 or 2 nose ribs to get access, again removing a rear rib to get drilling/riveting access is not as easy .
I think I will just remove the whole spar and do the job the easy way in a vertical drill stand,rather than fumbling
around leaning over the open nose skin .
Comment by Michael Rabe on November 14, 2009 at 5:02pm
Bucking solid rivets is not that difficult-even I can do it. If you have access to a pneumatic squeezer, it appears these could be squeezed with a 3" yoke but the rivets in the wing spar are too big for a hand squeezer though. I had never bucked any rivets when I built my spars last year. Just put together some practice pieces and buck a dozen or so until you have the hang of it. You don't want to try the first rivet on your spars but really, after a dozen practice pieces it is pretty straightforward. Measure the shop head with calipers and compare it to the rivet diameter for the first batch. The shop head (the part that gets deformed in the process) should be 1.5 times the rivet diameter. There is some tolerance though and that is spelled out in the Zenith building standards manual. I drove the rivets out of one of my spars this morning and let me tell you, they were in there good, I had to work to drive them out. But by supporting the spar with wood blocks on either side of the rivet they came out with NO damage to the spar. I really have to say that Zenith is REALLY doing a nice job on this upgrade information--This is a great company doing the right thing.
Comment by Dan Dempsey on November 14, 2009 at 3:46pm
I was glad to see rivets were an option. When I first saw the update plans I said "wow.. that's a lot of nuts and bolts!" I want to join the chorus of thanks for these blogs and videos.
Comment by Jake Reyna on November 14, 2009 at 2:04pm
For those of you that may not have the confidence to do solid rivets, if bolts aren't an option, unless you live out in the sticks, odds are there is somebody at your airport that can help. I've never met an RV builder that wouldn't take the time to help a fellow builder.

I chose to build the XL because I didn't want to buck thousands of rivets and I wanted to build without needing help. It's not as difficult as you may think and at this point there are no access issues. Most of what I've seen can be done by one person and some clamps. More importantly, you have videos to watch at your leisure :-) Get some ear plugs.
Comment by Larry Whitlow on November 14, 2009 at 12:36pm

I'm off to Harbor Freight for an Air Hammer and I may just pick up one of those Riveting Hammers when I'm there!!

As for the RV Maybe but I think I'm gonna do a 750 next for my Dad. The RV's Are really slick but I just like to Fun Fly!!!

But those RV's do look like fun!! Maybe if i hit the lottery and can spend my days building planes!!!!

Comment by Dave Roloff on November 14, 2009 at 11:52am
Thes ere becoming very helpful. Thanks. I have one wing to the point of ready to drill the solid rivets. It looks like the top leg of the new angle is longer than the old one. If this is the case, please make sure to address the wing baggage door hinges.

Comment by Jake Reyna on November 14, 2009 at 11:26am
I've been looking for a reason to buy another tool. I've purchased a number of tools at Harbor Freight, saved mucho dinero and have never been disappointed. They have a Riveting Hammer for $100. Think of it as experience if you ever decide to build an RV.

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