Well, Saturday has come and gone again, but still making progress on the right wing skeleton. Not a lot to show as much of what I did today is repetive work.
You may recall last week I started adding the flapperon arms to the rear wing ribs, using the same template method I used for the slat supports on the nose ribs. Today I wanted to continue this process and finish the other three for the right wing.
It's at this point that I remember, the first one I did is the only one where the rib flanges face inboard - on the rest or the rear ribs they face outboard. My template for the first won't work on the other three.
No matter, I just used the same process with the template facing the other way. To make the A5 rivet hole layouts consistent, I used a scrap piece of 016 to make a hole template for spacing the rivets the same as the first:
The process works well and things go faster with each one made. The other three came out perfectly:
With everything right size hole drilled, time to take it all apart, debur and scuff with ScotchBrite (I need to get some more!):
Clean with lacquer thinner and prime. I always prime anywhere two metal surfaces are sandwiched together. The main spar ends of the ribs will also be done when final holes are drilled. The flap arms and slat brackets will be done in gray primer as they are outside the surface of the wing skins. Something else I need to get more of - grey primer!
All six rear ribs primed, four with flap arm attach points, two without. Five nose ribs, four with slat attach points, one (closest in picture) with tie down ring bracket attach point. The 6th nose rib will be primed before final assembly. The root ribs will be primed in grey are they can be seen from the cockpit.
Also getting green prime are the nose skin support Ls and lower skin support Ls.
That was today's work, I'm almost ready for wing skins. I have 6 sheets of 020 aluminum on order and expect to pick it up this week or next.
I need to call Zenith on Monday to order some A6 rivets (apparently they are Zenith specific) and call ACS for a A5 strap duplicator tool.
My blog entries are sorted automatically by the publishing software I use in reverse chronological order. This is great for regular readers who get to see my latest posts on the front page. One of my regular readers pointed out that new followers might be better served however by starting at the beginning of this journey. In order to make that easier, I've added a button at the top right of the page which takes the reader right there.
Thanks to those that have been following since the journey began and for those just or recently joining me, thanks to you too.
Back in the shop today, getting more done on the right wing.
I started the day by deciding what i wanted to do next. The inboard rear channel doubler needs to be riveted to the channel. To do this, I first needed to drill the aft rib flanges out to A5. I could get the top two holes done, but the rear channel needed to be lifted to get the bottom ones because the table was in the way of keeping the drill straight.
Unlike the lower holes of the nose ribs at the spar, I made the room by removing the ribs from the spar but leaving them attached to the rear channel. I moved everything back to the edge of the table:
With all the holes in the rear channel upsized to A5 where necessary, I took the ribs off to drill the pilot holes for the lower skins to A3 on the inboard and outboard rear channels:
All holes are deburred and the parts for the rear channel are rubbed down with ScotchBrite.....
.....cleaned then primed:
To keep things straight for re-assembly with clecos, I finger clamped the rear channel to the top of the main spar:
It might seem I'm overdoing it with clecos but this is by design. Not only does this keep everything tight, but by adding a cleco in every hole I don't want to rivet yet, it prevents me from accidently doing just that and further not having to drill a perfectly good rivet out (a lesson I've learned already). The top of the doubler will be pilot holes for the top wing skin and top of the trailing edge skin, so I won't be riveting those yet. Same with the holes for the main ribs.
Same goes with the inboard rear channel doubler plate. I can't rivet it yet until I fit the first main rib (remember it tucks between the rear channel and the doubler plate). As a reminder, I filled those affected holes with clecos:
I decided it was better the lie the rear channel flat on the table to do the rivets on the doubler. Same process as every other long line of rivets - alternating holes, rivet between the clecos, then remove the clecos and finish the rest:
The centre channel doubler will be clecoed and riveted when I add the rear strut pickup. That will happen when the spar and wing skeleton get elevated up on square tubing. That will allow the flapperon brackets to be added as well.
With the rear channels complete and awaiting final assembly to the main ribs and wing skins, it was time to tackle the flapperon arms. First up was drilling the tip of the first one to A3 size. I didn't get a picture of the other three, but I did the same thing as the slat attach brackets for the nose ribs. Start with the first one, stack the rest together with a clamp and use the first as a pilot hole for the other three.
Using the same idea as the slat brackets, I laid out a work space. The plans call for the pilot hole to be 48mm below the lateral line of the wing rib back from the spar, and 894mm rearward from the spar.
To accomplish this, I laid the rib out on some boards and used a block (the purple one in the picture) as my "spar". With the rib in position, I traced it out on the board with a marker:
The crosshairs marked and A3 hole drilled on the lower board below represents where the pilot hole of the flapperon arm is positioned relative to the wing ribs as per the measurements described above:
A cleco holds the flapperon arm in position via the A3 pilot hole:
Pivoting the flapperon arm upwards and under the rib until the top edge of the arm meets the top of the rib flange as shown in the plans:
Remove the rib and the flapperon arm is in the exact position it needs to be:
Extending the lines of the flapperon arm "head" with marker lines makes it easy to reposition if necessary.....
....and allows me to visualize where the flapperon arm is relative to the rib when laying out the rivet pattern for attaching them together, This saves having to flip everything over and drilling from the arm side. A3 pilot holes are first drilled through the rib using the layout shown in the plans:
With the A3 pilot holes drilled, the arm is added back again, lined up and the pilot holes are drilled through the arm and clecoed to the board to keep everything straight and correct:
All holes, except the lower 4 are brought up to final A5 size:
The whole assembly if flipped over and a "L" bracket is added to support the lower wing skin at the rib/arm joint. The L is back-drilled suing the A3 holes then upsized to A5:
The skin support L in position on the flapperon arm:
The arm seems to stick out a long way to the rear from the rib, but it's deceiving to look at - the trailing edge skin still needs to be added to the aft of the rear wing channel. This will close the gap between the wing and flapperons substantially.
A good productive day. Next up will be the other three flapperon arms. With those complete, I can raise everything up on steel beams on the bench and start prepping the wing skins.
Even the little steps are getting me closer. Thanks for following along.
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.
Yet another delayed update on my blog. December was real busy with work (back on temporary assignment in the tech side, Monday to Friday) and the Christmas season. I didn't get the chance to post any updates - but things are coming along nicely.
I clecoed the main wing ribs to the spar, in preparation for mounting the rear wing channel.
Finger clamped the rear channel into place - very pleased with how it fits on the ribs. The ribs do have slight upward taper towards the rear, so I propped up the rear channel on shims and made sure everything was perfectly level and square.
I didn't get a bunch of pictures of the rear channel root doubler. It's made from 0.125 aluminum plate and sits inside the rear channel at the wing root end. The root rib (on the right) actually attaches to the channel slightly outboard from the inboard end of the channel and on top of the doubler. I had a real hard time getting the rear channel to line up perpendicular with the main wing spar and ribs working outboard to the tip. Turns out the rear flange of the first full rib (shown on the left) mounts to the rear channel between the doubler and channel. It doesn't sound like much, but makes a huge difference the further outboard you go. The angled root rib allows for the difference in thickness of the doubler.
Brenda invested in a CriCut Maker machine for herself for Christmas. The machine is a plotter/cutter for home crafters/makers. It's really cool; it prints, it cuts, it can emboss. Check it out here:
I got my first lesson in how to use it. Essentially you upload .SVG (simple vector graphics) to the proprietary software, modify as you wish and let the Maker machine create your items. It's real simple.
I chose some public domain SVG files of some logos for Ron's airplane and used the Maker to cut them out of basic construction paper. I was amazed at how well it cut them out. It can cut adhesive backed vinyl too among many other materials. This will be AMAZING for doing custom graphics and registration letters for our airplanes! I already have some ideas about other uses to, including cockpit panel overlays - carbon fibre vinyl anyone? So cool :)
Sometimes, I'm like a kid in a candy store. Anyhow, back to the build (focus Jason... focus)...
I noticed a discrepancy in my plans. The overall picture of the wing skin rivets show A5 rivets along the rear channel from root to tip (top of red arrows), but the side view shows A4 in the rear channel (bottom of red arrows). A head scratcher....
Here is where the internet is handy. I posted the question to the Zenith Builders Group on Facebook and with a few minutes had a better idea what should be happening here (thanks Skip Rudy for the picture below). I further clarified this with Roger at Zenith, he advised me A5 to station 2040, then A4 out to the tip, or just A5 all the way out.
With the rear channel and rib attachment points pilot drilled to A3 hole size, I took the rear channel back off the wing assembly and drilled the top holes along the length. I was so pleased with my progress.... until....
....I remembered that I should have left the top holes at A3. In my mind I had the answer, these are supposed to be A5.... eventually :( This will make drilling the holes in the skin more time consuming, but not a huge deal. At least I know they are correct.
Next task is to start adding the nose ribs to the spar. This is done by back drilling from the rear of the spar into the nose rib using the pilot holes drilled for the main ribs. When brought up to A5 size, these holes will be the connection between the nose rib and main rib, with the spar web in between.
All the nose ribs in position on the spar, perfectly level with the top and bottom spar caps.
Had to make some small adjustments on nose rib number 5 in order to be clear from the forward facing spar web doubler flange. This doesn't affect any structure, but make the nose rib fit proper (picture just after the cut was made to the flange, prior to debur):
Nose rib 5 now fits where it should:
With the nose ribs in place on the pilot holes, it's time to make the slat attachment skin support angles. It starts with a piece of standard L. Five points are measured out according to the build instructions, then drilled out to A5 size:
Notches are cut to the edges of the holes with snips, then everything is deburred with sandpaper and small round files. This angle can now be bent to form a rounded support for the nose skin.
Slat attach brackets are next. I scribed some Sharpie lines 10mm from the edges. Where they intersect is the attach holes where the slats will attach.
I stacked all four needed for the right wing, clamped them together and pilot dilled them to A3. Final holes will be drilled when the slats are attached to the wings.
I didn't capture in pictures how I got the slat attach bracket and skin support angle positioned on the first nose rib, but I used the same thinking as I did with the slats, seen on a previous blog post here
It turned out very well. This should go a long way to making the slats equal, straight and easy to install when the time comes.
Attachment in place, waiting on others to be completed (I'll likely use this one as the template for the rest). Will need to come off for debur and prime before final rivets. I might leave the rivets until the nose skins are cut and fit.
It's really starting to look like a wing with each passing shop session.
I've placed an order for more 020 aluminum as I am just about ready to skin this wing. Also need to order some Tefzel wire for the nav/strobe/landing lights and some plumbing pieces for the fuel system. So much to think of!
When a build like this all seems overwhelming (and it sometimes does - trust me), it pays to stop and admire the work being done. I sat on a stool for a quick drink of water and couldn't help notice the symmetry of the lightning holes in the nose ribs when looking in from the tip to the root. I can't believe it was over 3 years ago that I cut these rear and nose ribs out and debured the blanks. Unreal!
Thanks for continuing to follow along on my journey. Your support means a lot to me.
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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.