I did some initial bending of sample lines, but somehow couldn’t find out how the ‘hand tubeing bender’ works. After this experience I actually did RTFM!
And I watched several YouTube video’s that explained it. It always seems so simple when experts do it.

The bigger the frustration when you try it and you mangle a piece of Aluminum until it’s FUBAR.
First step is measuring the tube and cutting of the part you need for a specific Fuel line.

We need two feed lines (left and right) and a single return line. The ULPower 520 iSA is an electronic injected engine and requires a return line.
I decided to make a single return line to the left wing. The Sport Cruiser has a similar approach.

While my Dad uses a electric wire to bend a template, I’m widening the holes, so the Fuel lines and the grommet fit the hole.

The Fuel line cover plate needs to fit exactly in the corner of the ‘bend’.

We discuss how the routing of the left feed line relates to the return line. I figured that we should use different routing, but it is now too late. Good thing I had to redo everything

Next day, I concentrated on the Elevator tips.

The lead counter balance weight at the forward side of the elevator tab is trimmed aft as per the drawing. However in hind-side I think it would be better to trim it at the front.

At least then there is enough room for some glass fiber covering. Now I did create the glass fiber cover, only to grind it all away in the finishing.

In order to ‘connect’ he tip to the glass fiber front, I also put some resin on the tip itself.

The fit is good and no I can let it cure (dry) for some time.

After clecoing the tips to the Elevator, I can start riveting them together.

Because I don’t need ‘entry’ to the Elevator and Rudder tips, I use blind rivets to attach them. There is no way you can use ‘normal’ rivets. You could install screws, but that is overkill.

While the tips dry, I use the remaining epoxy resin (you always make too much), to fill the gap between the Elevator and the trim tab. The gap widens at the end and I want a consistent gap. Nothing a little resin can’t solve.

And while we’re at it, we also apply it to the blind rivets and the Glass Fiber – Aluminum connection.

Of course as a noob with resin, I apply too much and I regret it the next day when I have to grind all the excess resin away.
Oh well, learned yet some more.

Time: 5 Hours, Rivets: 11/3 (2020-04-11)

Time: 6 Hours, Rivets:  0/0 (2020-04-18)

Time: 4 Hours, Rivets: 19/0 (2020-04-19)

Time: 3 Hours, Rivets:  0/0 (2020-04-22)

Time: 3 Hours, Rivets:  0/0 (2020-04-23)

Time: 2 Hours, Rivets:  0/0 (2020-04-25)

Time: 2 Hours, Rivets:  0/0 (2020-04-26)

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In hind-side, I’d probably should have just finished it than and there, because It turns out I still do it at different times. On the other hand, it’s not a problem anyway. I just had to find the Tips in my storage rack.

From the factory, the preformed Elevator Tips fit quite nicely. Just a little trimming is enough.

Because the Tips are blind-riveted to the Elevator, with the Aluminum to the outside, the rivet in pulled to the fiberglass. To prevent pulling the rivet right through the fiberglass, you have to secure it on the inside. You can use either a small washer or aluminum strip. I decided to make custom ‘washers’ from Aluminum. just a strip cut into small squares and drill them.

As a final touch I dimpled the ‘washers’, so it is distributes the tension when pulling the rivet.

Drilling the holes though the Aluminum into the glassfiber works good. However you need to check if the Tip is straight on the Aluminum. The preformed fiberglass fits great, but it will not guarantee being aligned, so check it.

Flipping the Horizontal Stabilizer to drill the other side.
Another problem is the Lead weight on the forward part of the Elevator. In Hind-side (again) it’s better to trim it on the forward side, so you can comfortably make a fiberglass front piece to it.

I didn’t dimple the Aluminum, which is a good thing, as it made fitting the Tips much easier.

With some time left, we also started with the Rudder Tips (the top side. The Rudder Horn (bottom part) can only be done after fitting it to the tail. Because of the Tail wheel, you need to do some extra trimming.

Again after trimming I had to dimple the Aluminum (with the squeezer of course). I used the same Aluminum (custom) square ‘washers’ on the inside to prevent ripping the fiberglass when riveting.

Time: 5 Hours, Rivets: 31/1 (2020-03-29)

Time: 3 Hours, Rivets:  2/0 (2020-04-01)

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This provides a nice flat seal between both halves of the leading edge.
Now we can start rolling the edge itself. We use duct tape and several broom sticks (different diameter). The trick is to keep pressure downwards or else the edge will not be equal.

After rolling the edge, both halves need to be positioned (top side over the bottom side) and clecoed together. The holes need to be drilled with a #30 drill and then we can blind rivet the edge pieces together.

The result is a nice smooth leading edge. However I think I will use epoxy and some filler later to make the connection of both halves disappear, so it will look like a single sheet. Not sure about it, becouse it’s work and weight and probably not visible. So I will postpone this decision until I’ve finished the wings and do much of the epoxy work.

Good news from Van’s Aircraft: The Wing kit is in the crates and will be transported to the harbor for further shipping. Planned estimated time of arrival is currently set to February fifth.

Time: 3 Hours, Rivets: 72/0

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Also I can use the squeezer for the last millimeter to set the rivet just right.
About thirty years ago I studied at the mid-level technical school (MTS) and one of our assignments was to build a controllable transformer which allows both voltage and current regulation. It still works, so I used it to drive the Trim Tab servo. Set the voltage to 12V and keep the current on low to prevent damage.

There are two types of Trim Tab horns delivered with the kit. One specifically for the servo motor and one when using a Tram Tab cable control. I did several tests with both of them and my conclusion is that even though I have the servo motor, I will use the other horn. Reason is that the lower servo horn might damage the trim tab if set at the outer limits. The manual trim tab horn doesn’t, since it is higher and doesn’t touch anything if you let the servo go to both extremes.

The result will be that the Trim Tab will have just a little less range (3.5cm instead of 4.5cm), however the Trim Tab is seldom used all the way. That is a good argument to use the original one, but I also want to prevent damage in malfunction situations. Moreover I asked several RV-7 pilots in the Netherlands and they claim the Trim Tab is very sensitive. Using the higher horn also makes the Trim Tab less sensitive.

Result looks good, however I was short one blind rivet (MK-319-BS), which I ordered with the Wings.

Time: 3 Hours, Rivets: 34/4

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During scuffing and degreasing (let’s call it cleaning), I remembered that I should first scuff then dimple and after that degrease. Now I just wear the Scotch-Brite pads for no reason. Degreasing is also better after dimpling, but I probably grease the skin up again.

Last step before Priming the Elevator parts is the preparation of th paint. I use the light-green, one component self-etching wash primer (Sikkens Washprimer 1K CF) and mix it 2:1 with a reducer (Sikkens Reducer). This combination keeps the paint workable for at least one hour.

I definitely get better at my spray paint gun handling, but I’m still not satisfied. Although the result is not bad.

One improvement is increasing the work light while painting. Especially after spraying for 30 minutes and not having a professional air vent system, it get’s harder to see the result while spraying. Next time I’ll experiment with construction lighting, although this could produce shadows, so some experimentation is necessary.

Time: 4 Hours, Rivets: 0/0

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The Elevator Stiffeners are not symmetrical (left/right), because the left Elevator holds the Trim tab. So right of the bat there is a head-scratcher, because I assume symmetry. Ok, reading the short sentence again in the construction manual (and studying the drawing) did the trick.

I’m especially vigilant when wielding the snips, because cutting is a irreversible action. However the pre-manufactured Stiffeners of Van’s are drilled in such a way that it’s almost impossible to make a mistake.

For trimming the Stiffeners, I use the snips again, but keep at least one millimeter of margin, because I know my cutting skills and they haven’t improved much since grammar school. Hence I choose the easy way out. Which is, using the bench grinder. Really handy to “cut” the last part completely straight. To prevent burned fingers (been there), I use either a wooden brush or hammer.

To “finish” the edges of the Stiffeners, the Scotch-Bright wheel is brilliant. When it is not spinning, it looks soft, but at a few thousand revs, it grinds aluminum like a hot knife cuts butter. After this treatment the edges are smooth.

The Elevator Stiffeners don’t have all the holes pre-drilled. I’m not sure why Van’s does this (and the construction manual doesn’t elaborate on it), but it requires drilling the extra holes using the skin as a guide. Again, marking the Stiffeners after drilling is essential, as they will probably not be interchangeable after drilling.

All parts attached to skin, may they be spars, ribs, stiffeners or other skin, requires dimpling to enable flush riveting. Although the manual tells me to dimple both the Stiffeners and the skin, I decided to only do the Stiffeners and dimple the skin when I have it also match-drilled with the ribs and spar.
The Stiffeners are now ready for cleanup and priming.

Since the construction of the left and right Elevator spar and ribs is (or at least at this point looks) identical, I build them in parallel. Starting with the Spar and the counter balance rib including the counter balance weight. This weight is on the opposite side of the Elevator hinge, which should make the control on the stick weightless.
The fit of the counterbalance weight under the skin is tight.

You wouldn’t expect it, but drilling through lead is actually “harder” than you think. The lead somehow sticks to the drill and blocks the way. I tried oil, but the best way I found is small steps and cleaning the drill every time.

Time: 9 Hours, Rivets: 0/0

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