Back in the shop today. Made some moderate progress on the right wing.
I pleased that some of the lessons learned on previous sections are being applied in later sections. Since the start of this adventure, I've learned so much that some problems just seem simple now compared to before. Very satisfying.
One of the first parts I made for my plane were the root nose rib blanks. I remember being so proud of these and I should be - this wasn't something I'd done before. One thing that has obviously improved over time is the quality of my work and my eye for quality work. These original parts although fine, seem like I made them in a rush - perhaps caught up the excitement.
My originals are on the right. The tooling holes are too big and somewhat out of round. The relief holes aren't as accurate as they should be and the curve of the nose are kind of un-smooth.
I made some new ones (it took me a quarter of the time of the originals) and I'm very happy how they turned out - much nicer and certainly more accurate. The form block (I thought I was done with form blocks) fit really well with the proper size tooling holes.
To make these blanks, I used Ron's 701 templates as the design is the exact same. Unfortunately, Ron's 701 template has the tooling holes in the wrong spot on the forms, so I had to drill two extra holes to make the blank match the form. Not a huge deal, the forms made the nose ribs perfectly.
Placed on the spar in the correct position, it looks quite odd and stubby. The wing root tapers to the cabin roof line as does the wing nose skin.
For some reason, this small nose rib requires two A6 rivets, where the rest of the nose ribs along the wing use A5. I confirmed with some other builders who are using the kit that the plans are correct. I heard that Zenith used to use two A5 AND a bolt here! The A6 seems like overkill, but I'd prefer that than trying to fit a bolt.
To add to the strength here, a doubler plate is added across the spar web to connect the rear and nose root ribs. A5 rivets here too.
I had to do some more thinking on how I was going to do the rest of the slat support brackets. While I thought on that, I made the first of 2 wing tie down brackets. The step drill worked to create the large loop where tie down ropes will attach when the plane is parked out in the open.
The assembly picture guides provided online by Zenith for builders are quite detailed. Designed for the kit builder primarily, they can be good for scratch builders to get a picture in their hed how the final assembly will look. Remember, most kit parts come pre-drilled. I'm doing all the drilling.
Here the tie-down bracket is mated to the number 5 nose rib, and it gets riveted to the back edge of the rib and will be tight against the spar.
Six A5 rivets will keep this together. I won't rivet this until I can cut the slots in the lower nose skin that allows this to protrude below the wing.
While I deburred the tie down and nose rib junction, I decided the best way to keep the slat brackets the same across the 4 different ribs was to use a wood template (just like I did for the support brackets on the slat ribs).
I started with the nose rib I did last week as my template. I laid it down on the wood and drilled through the front bracket holes then clecoed it down the wood. I then traced a rough outline of the nose rib and the slat bracket onto the wood.
Removing the original, I could now cleco a new slat bracket in the exact same position as the first.
The new rib is laid over the slat bracket in the exact position as the first. A measurement from the tip of the nose rib to the clecoed bracket holes proves it's exact like the other.
Flipping them both over, I can trace the outline of the slat bracket on the face of the rib. This allows the correct positioning of the skin support L. Drill through the L into the nose rib - these will be the holes for all three pieces.
Remove the support L and lay everything back on the template board and cleco the slat support. Back drill through the nose rib into the slat support, and cleco as you go.
I made quick work of the four slat support brackets and their support L. I re-added the support L to the assembly and drilled them all out to A4 (final size). The accuracy realized by this method is excellent.
Looking outboard from nose rib #1. I have #2 and #5 removed at this point for further fitting.
With the ribs, slat supports and tie down ring fit, I upsized the rib holes to A5 (final size), with the exception of the lowest holes. I'll need to wait until the wing skeleton gets elevated off the table or flipped over - I can't get the drill level because of the table.
Definitely a productive day in the shop.
I'm waiting to hear back from a supplier regarding some 020 aluminum sheets so I can start skinning the wings. It will be top skins first, followed by bottom skins, trailing edge skins and nose skins. Lots still to do, but progress none-the-less. I also need to order some A6 rivets (I better look to seem how many more I need!) and start thinking about fuel tanks and fuel line plumbing.
I happened to glance at the Zenith online parts catalogue today, looking for A6 rivets. Did you know ONE wing spar assembly is over $4000 USD if ordered as a complete assembly from the factory?!?! That's crazy! I have probably $400 CAD TOTAL of materials into both my spars. Sure, I've spent lots of hours of labour, but the lessons learned and fun had along the way - priceless!
Thanks for following along, stay tuned for more.
Husband, father and 911 dispatcher. Long time pilot with a licence that burns a hole in my pocket where my student loan money used to be. First time aircraft builder. Looking to fly my own airplane.