8 Jan 2012: Elevator 11 and last

Hours today:	2.8	Hours empennage:	94.9	Hours total:	94.9
Rivets today:	80	Rivets empennage:	2079	Rivets total:	2079

Drilled, dimpled and countersunk fairings. Reworked epoxy on strips. Riveted fairings to rudder. Attached rivnuts around inspection hatch using loctite and rivnut tool. Put hatch into place, so as not to lose hatch or little screws.

I’m all done! Put temporary nuts and bolts into the hinge and hanged the HS and rudder on the workshop wall. There is a small discrepancy between the angles of the two horns. I’ll see later if it has to be rectified, or if I can live with it. The flash lighting didn’t make a gorgeous picture, but you’ll get the idea.

The horizontal stabilizer and rudder hanging like a trophy on the garage wall.

Doing a flush countersunk and primed empennage only took a little more than triple the estimated time! And I haven’t started the body filler work yet. I’m surprised TAF only charge R45k for this option on their ready built models.

7 Jan 2012: Elevator 10

Hours today:	3.8	Hours empennage:	92.1	Hours total:	92.1
Rivets today:	491	Rivets empennage:	1999	Rivets total:	1999

Riveted the skins to the frames. Attempted to follow the instructions by lying both elevators on a flat surface, and tried to get them to line up. I’ll know how successful I was when the elevator meets the horizontal stabilizer, but it looks pretty good. The work involved making a lot of short rivets: 37 were required for the sharp ends of the ribs, and for one side of the channel that holds the elevator.

Also epoxied aluminium strips to the insides of the two fairings that go on the ends of the elevator.

6 Jan 2012: Elevator 9

Hours today:	0.8	Hours empennage:	88.3	Hours total:	88.3
Rivets today:	9	Rivets empennage:	1508	Rivets total:	1508

Took advantage of the good weather to take my cleco removal slave to a nearby water part.

Before we left, I riveted the channel that holds the trim tab to the two ribs that hold it. I then cleco’d all four skins to the frame, and riveted the two small angle plates that go between the trim tab channel and two of the ribs near it. This is tricky, as it is difficult to support the plates while getting them into place. I used a bit of masking tape, later removed. I checked the integrity of the rivets by carefully bending back the skins away from the riveted areas.

5 Jan 2012: Elevator 8

Hours today:	2.6	Hours empennage:	87.5	Hours total:	87.5
Rivets today:	0	Rivets empennage:	1499	Rivets total:	1499

Primed the second large skin, the one for the right hand side elevator that does not contain a trim tab. Also prepped then primed the two small skins that go over the horns on either side of the elevator.

Test fit everything: the channel that the trim-tab connects to is now about the right width and at the right angle. Did some adjusting of flanges on the ribs to make sure that everything would lie flat when riveted.

4 Jan 2012: Elevator 7

Hours today:	2.6	Hours empennage:	84.9	Hours total:	84.9
Rivets today:	0	Rivets empennage:	1499	Rivets total:	1499

Prepped the second large skin for priming by deburring the holes, roughing the skin with scotch-brite, then degreasing with lacquer thinners. Test fit the first large skin, which is the one that contains the trim tab. Found that the channel that the trim-tab connects to has been squeezed too thin, so opened it out a bit.

3 Jan 2012: Elevator 6

Hours today:	2.9	Hours empennage:	82.3	Hours total:	82.3
Rivets today:	38	Rivets empennage:	1499	Rivets total:	1499

Went to the factory to collect the missing box channel. On getting it home, prepped it for priming and primed. With all the frame components to hand, completed riveting the frame for the elevator. Also finished priming first large skin.

 

2 Jan 2012: Elevator 5

Hours today:	6.8	Hours empennage:	79.4	Hours total:	79.4
Rivets today:	67	Rivets empennage:	1461	Rivets total:	1461

Assembled the elevator frame, except for the outside ribs and the box cover to the middle hinge. The box cover channel was missing from the kit. Prepped one skin for priming, and primed all the rest of the frame parts.

Center structure of elevator

1 Jan 2012: Elevator 4

Hours today:	5.3	Hours empennage:	72.6	Hours total:	72.6
Rivets today:	0	Rivets empennage:	1394	Rivets total:	1394

Why no, I don’t have a life.

I gave the parts a third coat of primer then turned them over and sprayed the other side. I deburring, dimpled, roughed and degreased the remaining pieces of the elevator frame.

31 Dec 2011: Elevator 3

Hours today:	3.0	Hours empennage:	67.3	Hours total:	67.3
Rivets today:	0	Rivets empennage:	1394	Rivets total:	1394

I prepped the main channels and a couple of the other parts around the centre: deburred, roughened and gave two coats of primer. I’m finding working without the deadline of a massive painting job is quite a bit more relaxed.

 

30 Dec 2011: Elevator 2

Hours today:	3.5	Hours empennage:	64.3	Hours total:	64.3
Rivets today:	34	Rivets empennage:	1394	Rivets total:	1394

I spent a quite a bit of time figuring out how to countersink the rivets on the trim tab. There isn’t any space to get a tool in behind the lower flap on the trim tab to countersink it. There also wouldn’t be any space for the back of a rivet if it was countersunk. Eventually I decided to dimple the upper skin of the trim tab, countersink the hing deeply, then countersink the lower skin of the trim tab just a little.

Design for countersunk rivets on elevator trim

The top row of holes is the top skin of the tab, countersunk. The third row of the holes is the hinge, countersunk to allow the top skin to mate flat. The second row of holes from the top is the bottom skin, which is just a little countersunk to catch the remainder of the dimple from the top skin.The bottom row is the other side of the hinge that attaches to the elevator, ready dimpled.

The next trick was that short rivets are needed. I’ve made a little tool to hold rivets while cutting them down, and made about 28 today, 4mm countersunk, 5.5mm long. The rivets went through the three layers (upper skin, hinge, lower skin) perfectly, and the hole construction looks strong.

There were a couple of downsides. Somehow I put a curve on the bottom of the tab, which didn’t play nicely with the flat horns. The other major issue is that there is almost no clearance between the bottom skin and the bottom of the tab. So, clecos that went in pinged off the skin and left marks. I hope they’ll rub out.

Here’s the finished product:

Finished trim tab hinge

Another problem reveals itself in the photo: because the  rivets were cut down, the breaking point of the stalk is at or above the surface. I’m going to have to grind all the stalks down to put them below the surface of the skin.

After that excitement, I deburred and finished the horns and their brackets, and riveted those together with the stainless steel rivets. I’ve decided on the elevator not to prime surfaces that will be on the outside of the aircraft, as far as possible. I’m working my way round the parts in the centre, deburring, dimpling and preparing for primer spray.