Month: January 2020

Today I squeezed all the forward spar flange-to-skin rivets, and the outboard rib flange rivets. Also riveted the skin to counter-weight skin rivets.

Starting with the left elevator, I squeezed the rivets in the spar flange, where the clecos are showing in this picture.

Then the left outboard rib flanges, except the aft 4 rivets, as these will be set once the trailing edge is done.

Then it was a repeat on the right elevator. Everything went well, and I’m now ready to tackle the trailing edges for both elevators.

Over the last couple of days I’ve been working on riveting the inboard ends of the elevators.

Mostly it has been fine, but a couple of rivets have been frustrating.

The left elevator has a flange on the aft end of the inboard rib. Access to the two rivets is tight, and I struggled to get both of the in. The plans say to use a flush rivet set on the universal rivet heads where access is tight. It’s hard to get a squeezer in there, so I ended up bucking them both. The bucking bar scruffier the tops of the adjacent rivets, which looks ugly, but is not really a problem. I’m going to replace these two rivets on the flange, but decided to move on for now, so I don’t waste too much time here.

Luckily the other rivets have all been much easier to access. The two rivets connecting the gusset and the spar were reachable with the squeezer, and came out great. As did the pop rivets for the trim tab brace.

Then it was on to the inboard rib top and bottom flanges, which went smoothly.

With that done on both elevators, I riveted the left elevator top skin to the forward spar. Here it is flipped over, with the top skin riveted, and the bottom skin ready for skin/spar riveting.

Today I riveted the main elevator spars to the ribs. This was quite easy, as it was pop riveting with easy access.

Here’s the inboard rib connected to the main spar with three pop rivets. Each elevator has 6 ribs.

I used a weighted board to hold the elevator flat while riveting. Despite the precaution, I noticed afterwards that the elevator has a slight bend from one end to the other, perhaps 1/8 of an inch. Not sure if it’ll change once the skin is riveted onto the main spar flange, we shall see.

Last night I finished riveting the ribs together on both elevators. Tonight I made a straight table top to help with steps that require a straight surface.

The rib riveting was less challenging than I thought, and I was able to make some good progress last night. The ribs are in two parts, one part riveted to the each of the skins. Then the two pieces are riveted together. Access to the aft two rivets in each rib is very limited, so a decent amount of time was needed to get each rivet ready to go. In the end it all worked out.

The only issue was an incompletely removed rivet shank, in a place that was very hard to access. I left it in there, as there’s nothing for it to interfere with.

The end result was good, lots of neatly riveted ribs. The front riveted were done with a pneumatic pop riveted, which sped up the whole process.

With those rivets set, I clecoed the front spar assembly to each elevator.

The next few steps include attaching the forward spar, and then riveting the root and tip ribs to the skin, then it’s trailing edge time, servo install, trim tab install, and then rolling the leading edges.

Today I riveted the elevator rear spars to the left bottom, and right top skins, joining the two half’s of each elevator.

Because the rear spar is around 6 inches forward of the trailing edge, access to the rivets is difficult. I bought the long bucking bar, which makes the process very simple. The bar is specifically shaped for this step, and once inserted between the two skins, a little down force on the back of the bar gives plenty of leverage on the back of the rivet (edge of bench is the fulcrum). The elevator is shimmed up to account for the trailing edge break.

The plans suggest starting with the left elevator to get used to the bucking bar on a bottom skin. It turned out to be easy to use. Here’s what it looks like with the bucking bar between the skins.

With the left elevator rivets bucked, I squeezed all the remaining rivets where the trim tab cutout gives access to the spar.

Then a repeat of the process for the right elevator, this time working with the top skin. Everything went well.

Hard to see in the picture, but this is the row of bucked rivets in the right elevator.

Now that these skins are all assembled, it’s much easier to keep everything organized because there are fewer parts. Will be good to get the front spars attached, that will give me even more space to work.

Tomorrow evening I’ll start riveting the ribs together inside the elevators. Access is going to be hard for the rear rivets, so I’m anticipating it may take a couple of sessions to get it done.

After a two week break over Christmas and New Year, I spend a few hours today back-riveting the ribs and elevator trim access doubler, and riveting the right rear spar to one of the skins.

First I back riveted the left elevator ribs to the bottom skin. Here’s a picture of the right elevator at the same stage, which I did later in the day.

Next I riveted the right rear spar to the right elevator bottom skin. This calls for clamping to an edge, then shimming the ribs up so they don’t bend.

Then it was time to rivet the skin to the spar. This went well with no issues. I have a new camera in the garage to capture stills and video, I’m trying it out to see if it’s useful for helping document the build process.

Installing the doubler was a little tricky. I back riveted most of the rivets, but some were in awkward locations, so I squeezed a few. The 3-3.5 rivets are a little long, and a few of my rivets were less than perfect, but nothing I felt was worth removing and redoing.

Then I back riveted ribs to the top skins for both elevators. Here’s a picture of the left elevator tip skin with ribs riveted.

The next step is to join the skins by riveting them to the rear spar, then riveting the ribs together. Then the front spar gets attached, then lots of odd rivets to close out the elevators, then the trailing edge, and finally rolling and riveting the front edges. Feels like the end is in sight for the elevators!