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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Before trimming we drill a hole in the corner, because snipping into a corner will result in crackling. By drilling a hole, we prevent stress in the Aluminum. Now we can use the left and right snips to trim the Horizontal Stabilizer.

On both sides we had the “First time right”. The Elevators fitted perfectly in the trimmed Horizontal Stabilizer.

After fastening the hinges and drilling the center hinge holes in the Elevator holes, we could finally attach the Elevators to the Horizontal Stabilizer. Look at the size of this part.

So after 129 hours the Empennage is finished. That is to say, I didn’t do the fairings of the Rudder and the Elevators, but as mentioned before, I’ll pick this up as I do the fairings of the Wings.

Time: 4 Hours, Rivets: 0/0

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Once the hinges are inserted I can start fitting the Rudder to the Vertical Stabilizer. It takes several times to attach and detach it again and adjust the hinges. I found that if I set the top and bottom hinge I can adjust the middle to align all three of them.

After hinge alignment I fastened the bolts and here is the attached Rudder to the Vertical Stabilizer in the correct position.

This part can now be shelved for when I start working on the fairings. The nice part is that the counter balance weight arm of the Rudder fits perfectly into the Vertical Stabilizer skin cutout.

The counter balance weight arm of the Elevators however do not fit into the Horizontal Stabilizer skin cutout. Strange, because I don’t see why Van’s cannot prepare that properly (just is with the Vertical Stabilizer). So I inserted the hinges in the Elevators, but did not have enough time to start trimming the skin.

Next time I’ll trim the skin and attach the Elevators to the Horizontal Stabilizer.

Time: 2 Hours, Rivets: 0/0

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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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There is one particular rivet (in the corner of the ribs and the spar) that needs to be longer, because it has extra material to go through. During my rivet check, I found I used the too short 4/16″ while it needed to be the 5/16″. If I had used the Go-NoGo gauge, it would be a NoGo, which would have saved me the burden of drilling it out.

Again I needed to drill out and reset several rivets, but this time I know the cause. There are a few rivets with different lengths and in that case I also need to adjust the squeezer, which I tend to forget.
On the aft side of the left Elevator there is a small spar to attach the piano hinge for the Trim Tab. I was certain that I could rivet those with normal rivets, although the plans called out for blind rivets. Again the plans were right, there is just not enough space to rivet them.

With the “standard” (most convenient) yoke you cannot rivet in tight spaces (trailing edges). Hence I switched to my 4″ yoke which only has a rivet set on one side and the other side is not that thick. Now I can set a few more rivets.

Unfortunately the last rivet on either side is still not possible with the squeezer. If I remember correctly I used a barn-door-hinge when riveting the rudder trailing edge. I’ll have to check my blog to see what I did there. I know the result was good.
Almost done with the Elevators, ETA on the Wings is early February, so most likely I will have some idle time.

Time: 4 Hours, Rivets: 297/5

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The drawings call out for blind rivets, however I think I can manage to rivet them with “normal” flush rivets.
Bending the trailing edge requires considerable pressure. It’s important to bend it just enough. If you bend it too little, the edge will be concave. If you bend it too much it will turn out concave.

The intended result is that the trailing edge of the Elevator is exactly straight. Measuring it with a ruler, there should be no light between the ruler and the trailing edge. The control surfaces of the plane do not have a wing profile, they are completely straight.

while attaching the skin to the right Elevator I found a piece of Styrofoam still being in between the stiffeners. This time we could laugh about it, after riveting the skin to the understructure, it would not be as amusing.

Although I still don’t have the new piano hinge, I use tho old one (the one I screwed up) to fit the trim tab. The sides of the trim tab fit nice into the left Elevator.
Here we are drilling the piano hinge to the left Elevator.

Now we can fit the connecting rod from the servo motor to the trim tab. One of the NVAV members warned me that the distance between the servo motor and the brackets was too small for the rivets to set. He used washers between the servo motor and the brackets. I’ve decided to counter sink those two rivets instead of dimpling them. This worked great (thanks Victor).

We tested the servo motor and it works great. Next time I can start riveting the skins to the understructure.

Time: 4 Hours, Rivets: 18/0

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Unfortunately I couldn’t use the squeezer for the Tip rib and the Counter weight rib, because it has flanges on both sides.
Something clearly is wrong here. I didn’t hold the bucking bar right on this one.

Rivets that are not set correctly need to be drilled out and reset. I keep this “score” in the right side bar. You can see the number of set rivets and reset rivets (after drilling out). Today was a bad day for this particular statistic, because over 10% of my rivets needed resetting (probably my worst score until now).

I could use the squeezer on the spar, but again a lot of rivets didn’t pass my QA. I’m not sure what the reason was, but in the end it got better

Here is a close-up of the result with the reinforcement plate and the plate nut. This platenut will hold the thread of the hinge attaching the Elevator to the Horizontal Stabilizer.

The side rib needs to be riveted with flush rivets, because the control horn goes over these rivets. This horn (the white part in the picture) is attached to the push rod attached to the control stick in the cockpit. This way you can turn the Elevators and let the plane climb or descend.

Here is the right Elevator with the attached control horn.

Next up, bending the trailing edges of the Elevators and, attaching the skin to understructure and finish the trim tab.

Time: 5 Hours, Rivets: 108/13

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Easy things first, riveting the stiffeners to the right Elevator. Just as with the Rudder, I use a little structural epoxy at the ends of the stiffeners, to reduce vibrations. This time with back riveting I accidentally riveted next to the back rivet plate in the MDF (three times). Fortunately this only ruins the MDF plate and probably the rivet, but I threw it away just to be sure.

In order to rivet the end of the stiffener at the trailing edge of the Elevator, you have to both press the stiffener and bend (open) the pre-bend skin. This feels scary, but it is ok. I applied some duct tape to the top of my rivet gun to prevent scratching the inside prime job.

After back riveting all stiffeners of both the right and left Elevator, I also back riveted the Trim tab reinforcement plate to left Elevator. I’m not sure how it happened, but I managed to screw up two rivets, so I had to drill them out and reset them. I’m getting better and better in drilling out rivets (not sure if that is good or bad).

I also screwed up the first rivet of the first stiffener, because I had issues with bending the skin. So in total three rivet reset.

We had a lot of snow today and I had to shovel my way out of the workshop. However with the extra heater in the workshop, the temperature was very nice, even though I don’t heat it that much.

Time: 5 Hours, Rivets: 254/3

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