Author Archives: Michael

Time: 7 Hours

Today started with a couple of hours of deburring and edge finishing on all the fuel tank z brackets. I then hit them all with a scotch-brite pad and cleaned them with some denatured alcohol. I relabeled them with a sharpie and covered the flange that will go up against the fuel tank baffle with blue tape. This is the only surface that I don’t want to prime so that it can be ProSealed. Then they went to the paint table to get primed.

As the brackets were drying I started work on the 3 nutplates that get riveted to the main spar for the inboard most z bracket. The nutplates go on the aft side of the spar and need countersinks on the forward side of the spar so the rivets sit flush. I set up the countersink cage with my #40 bit and drilled them after I reamed the holes.

The only way I could rivet the nutplates was with my gun and bucking bar, and it was tight with the spar doubler plate.

Next up was to fabricate the fuel tank stiffeners that go on the bottom of the inside of the tanks. Van’s sends them in a long piece with notches in them to guide you on their shape.

I rough cut them with the snips and bandsaw.

I then shaped all the corners and debured all the edges and organized them. The brackets were also dry and so I organized them as well.

A pretty good day in the Hangar! Tomorrow I will get to match drilling the stiffeners and skins.

Time: 3 Hours

I had a long day trip to our home base in Omaha, NE today. That meant I would have access to our mechanics great workshop. So I loaded up some tools and all my z brackets for the tanks before I left this morning. First up was to drill each bracket for the 3 nutplates that they needed. I used a K1000-3 nutplate as a templet for drilling by threading an AN3-4 bolt with 5 washers on it so it just grabbed the threads. That centered the nutplate over the bolt hole and allowed me to fine tune the wings of the nutplate so that they were parallel with bracket web. To help hold it while drilling I used a wide mouth vise grip pliers.

I just worked one nutplate at a time and then moved to the next two. Once that was done I loaded up my #40 countersink in the drill and took the brackets over to the bench vise and countersunk the bottoms of the brackets for the AD426 rivets.

Not a bad day of work especially since I was out of town and was at work! Next up will be to treat all the edges if the brackets and clean them up for priming minus the edge that gets riveted to the baffle as that will have ProSeal on then I will rivet the nut plates to them.

Time: 2 Hours

Got home from a day trip to AR tonight and decided to get a little work done in the Hangar. I needed to repeat the whole process I did on the left wing to the right wing. I didn’t take a lot of photos tonight as it would have been just like the left wing photos. Here were a couple I did take.

I did allow my cats out in the hangar this weekend and they loved it so now they keep me company when I’m home alone and drilling away!

It is amazing how much faster I can work on the second wing after I have learned the steps on the first one. It was definitely worth building both at the same time! Next up will be all the nut plates that I have to attach to the z brackets. There are 6 per wing for a total of 12, each getting three nut plates. Do the math and that’s 36 and each gets two holes drilled for a total of 72! Should be a fun project!

Time: 5 Hours

Today I set out to get at least one fuel tank attach points done. There are seven z shaped brackets that hold the fuel tank to the main spar. It seems like a general consensus that there is a better way to attach all the parts than what Van’s describes in the plans. The method was known as the “Checkoway” method after a builder that documented it. He has recently come out and asked that the credit be given to the builder that he learned it from and developed it, Steve Hurlbut. I started out by marking seven left and right brackets.

I then marked the center on one flange of each bracket. Van’s wants you to mark the hole dead center of the flange both length and width. Six of the brackets will have nut plates attached to them for the bolts to come up through the main spar web and attach to them. One bracket, the inboard one, will have the bolts go through them down through the main spar web to nut plates that are attached to the main spar. I followed other builders that shifted the center line on the inboard bracket away from the bracket web by 1/16″. This allows the head of the bolt to move away from the bracket web and allow a socket to go over the bolt. The other six brackets have the centerline moved towards the bracket web. These ones don’t have the need for a socket since the bolt comes up through the main spar and into a nut plate. This shift of the center line allows for a little more room on the opposite flange where these brackets will be blind riveted to the fuel tank baffle. Builders usually have to grind down the head of a blind rivet puller tool, this shift reduces the amount of grinding needed. After making all the marks on the flanges I set up the drill press and hit the inboard brackets for the left and right.

I then adjusted the drill for the different holes, here you can see the two different centers.

Hitting all the center holes didn’t take too long once I had the drill press setup.

The next step is to bolt the brackets to the main spar and square them up. You need to make sure you have the orientation correct for all seven brackets per the plans.

With all the brackets bolted and square to the main spar you can drill the other holes by match drilling up through the spar web and attach bolts to those holes.

Now all the brackets are bolted and square you can place the tank back on the spar. Once you have the tank in place you need to make all the seams tight between the leading edge and the tank and the tank skin and the top skin. I used two ratchet straps with a couple rags to get the fit nice and tight, I used a couple pieces of wood to give the straps to bind against at the rear spar so it wouldn’t bend the aft end of the top skin.

All the joint were nice and tight and looked great. The next step is to match drill the the skin splice between the outboard leading edge skin and the tank skin. These need a #19 drill bit for the AN509-8R8 screws that will go here.

Next up is to drill the five inboard holes through the baffle and the inboard z bracket.

With those holes clekoed you move to the other end. To get access to that end you need to remove the outboard leading edge.

Now that you have both ends of the baffle/end ribs attached to the z brackets you can remove the skin and center ribs as a unit leaving the baffle and the outboard/inboard ribs.

What this does is give you access to the baffle holes that you can now use to match drill the z brackets that are below it. So I drilled and attached the baffle to the brackets with the help of my beautiful girlfriend Tricia. I love that she wants to be so involved with the build and can’t wait to fly with me and take some really cool trips! Thanks T!

With those done I removed all the cleckos and replaced the skin/rib assembly. I could then remove the tank leaving the drilled z brackets behind with the spar.

This method ensures that all the attach point are good but also are all inline for a tight fit of the tank to the wing and other leading edge. It was a long day and I decided to clean up the shop and put the tools away for the night. I will repeat the whole process for the right wing next.

Time: 3 Hours

The right tank ribs went into the skin a little easier than the left ones did. I noticed that the right tank skin was not compressed as much which probably accounted for the easier rib installation.

I was able to use the cradle on this side which makes the whole process easier as it holds all the parts in the right place. Hopefully the left tank skin will hold the shape after being together which will help down the road, we will see. I grabbed the tank baffle (I did this on the left tank as well) and put it in place.

I placed the tank on the spar and it matched up as nice as the left side. Next up the Z brackets that are part of the tank to spar attachment.