Tag Archives: Elevator

Elevator Trim tab & left fiberglass tip fitting

Hours: 4

With the two main skins fitted onto the Elevator, I started looking at the trim tab and the side fiberglass tips.

First I figured out the correct orientation of the hinge that connects the Elevator and the trim tab and the right orientation of the trim tab. I temporarily clecoed them together to check that the clearances are good and it moves all fine.
Elevator trim tab temporarily mounted

Then I was searching for the brackets that go on top of the trim tab and realized that I got two different looking brackets. Since this looked off to me, I tried to squint real hard at the instruction manual to figure out which bracket is the right one. I also checked the Sling 4 instructions and asked Matthew if he had a picture of his brackets and with that figured out that I must have received one TSi and one Sling 4 bracket, so I put in a note with the factory so I can get the right bracket for my TSi.
This looked off to me - I figured out it's one TSi and one Sling 4 Trim tab bracket
Investigative work to figure out which bracket belongs

Securing the trim tab piano hinge

With that out of the way, I focused on thinking about securing the piano hinge that attaches the trim tab to the elevator. Since there is no natural stop for the pin that goes through the hinge on either side, it could happen that it becomes lose from vibration and thus could come out during flight, which would be bad. I research a bit on the topic and found this article from EAA on the use and installation of piano hinges.

One of the ways to secure the hinge is to drill a small hole through the last part of the hinge and install a safety wire. My hinge was luckily cut in a way that makes this approach very easy to achieve. I got out a small drill bit, mounted the hinge in my bench vise and drilled a hole on each side so I could run a safety wire through it.
EAA diagram to safety the hinge Hinge mounted in my bench vise to drill the hole for the safety wire Hole drilled for the safety wire Safety wire in place to test free movement while connected to the Elevator

Using the safety wire approach makes it easy to still remove it in the future, but ensures that the pin stays securely in the hinge.
Testing free movement of the trim tab with the safety wire in place

Fitting the left side fiberglass tip

For the last part of the day, I started on fitting the last part of the skin and the fiberglass tips. Since this requires moving around the tip from both sides, I moved the Elevator over onto some saw horses so I could access the bottom more easily.

First I clecoed the top skin in place and then I slowly fitted the fiberglass tip in place. In order to get the fiberglass tip to fit, I had to file a tiny bit at the back, but it was much easier than the Rudder tip fitting.

Once I had it in place, I started to hold everything tight together and started match-drilling holes into the fiberglass tip. I used liberal amounts of clecos to get a tight fit and everything looks good. Now I just need to repeat it on the other side.
Top skin clecoed in place Fiberglass tip fit in place and ready to match-drill Marking drill holes Fiberglass tip match-drilled

Elevator skin fitting

Hours: 3

First order of business for the Elevator skin was inspecting all edges and holes and there were a few edges that needed some deburring action.
Elevator skin edges needed some filing to remove the burrs

After deburring everything that needed attention, we wrapped the skins around the rib structure. Since the Elevator is a pretty big part, it was very helpful to have a second pair of hands for this.

The last thing I had to do before I can start on closing up the skin is to install the backing plate for the Trim motor inspection plate. The plans call for 1/8 rivets, but the holes were actually 3/32, so I had to first up-drill them. There’s also another small error in the plan, in that it says to rivet all 8 holes, but actually only 7 should be riveted, since the top hole is for the screw that holds the inspection plate in place.
Backing plate goes under the skin Holes are 3/32, so I needed to up-drill them to fit the 1/8 rivets Holes up-drilled and backing plate clecoed in place Quick test fit of the inspection plate

Elevator structure

Hours: 5.25

Time to finish off the Empennage and get the Elevator structure going. I received the replacement ribs that are bent just that little bit more in order to properly align with the reinforcement plates and skins and went to work to drill out the bad ribs and put in the replacements.

New ribs in place and a final picture of a few rivets that people that visited helped pull

After that, I went to work and torqued the bolts that connect the control rod and counterweight to the Elevator. There’s also a small support bracket that reinforces the center rib to spar attachment, which is a pretty tight fit, so I had to get out the manual hand riveter.
Torquing the AN bolts Bolts torqued and support plate riveted

My brother is currently visiting and is enjoying the riveting experience.
My brother enjoying the riveting experience

Once the center ribs were finished, we moved on to put the rest of the rib structure in place.Elevator rib structure finished Clecoing the ribs in place

After that I realized there’s a mistake in the plans as they instruct to rivet the edges that hold some of the side counterweights on, but there’s another small end rib that actually has to go on there as I found out after I checked the overall plan for the Elevator. Quickly drilled out the rivets and riveted on the part. A nice trick I learned from another builder for drilling out the rivets without damaging the holes they go through, is to only drill out the top of the rivet (the donut ring) and then use the center punch to push out the back of the rivet. This way you have less chance of enlarging the hole.
Error in the plan says to just rivet the endcap, but actually this part needs to be riveted onto the side End rib where it should go Holes drilled out and end rib ready to rivet

With the rib structure in place, time to work on fitting the skin.

More Elevator priming & assembling center spar structure

Hours: 5

With the weather warming up, I got to spend some time sitting in a bit of sun with the garage door open and preparing, deburring, cleaning and then priming more parts of the Elevator.

Laying out and preparing Elevator parts Primed Elevator parts

Assembling Elevator center spar

The first thing I put together was the Center Spar itself, which I had primed already together with the counterweight the other day. Setting everything up was pretty straight forward as usual and while I was working on it I had a visit from another builder of the EAA chapter I’m part of who actually happens to live very close by and is building an RV. And then another friend was visiting and I happened to have some rivets ready to be riveted, so I continue my new tradition to have guests pull a rivet on the plane and sign it.

Elevator Center Spar Elevator Center Spar riveted

Assembling the center structure to the spar

After the priming from yesterday had some time to dry and set, I went to work to put together the center rib assembly with the center spar. There are a lot of pieces that slot together in there, so it took some time to figure out what slots into which piece. for the center channel to go on:
Center Channel in place

Unfortunately I encountered a problem with the alignment of the holes on the center Rib, both left and right, with the plate as seen below:
Rib holes misaligned with the center plate Closeup of the misalignment of the elevator rib

In trying to figure out which piece is wrong, I started putting together more of the structure temporarily with clecos and the strange thing is that the other holes on the ribs are aligned fine (the black clecos below), so then I thought that it must be the top center plate.

More of the Elevator center structure in place

But then I took off the center plate to check its alignment with the outer skin and there the holes of the top center plate align correctly with the holes on the skin. So this in turn then lead me back to determining that the top (and bottom) holes on the Rib 1 must be the culprit.

It is very strange since the misalignment is pretty severe. It definitely doesn’t look like this could just be resolved by up-drilling the holes, so I sent a note to the factory to ask how to proceed. My guess is going to be that I need new center ribs.

 

Elevator priming & counterweight riveting

Hours: 4

While I was waiting for some parts to complete the ribs for the Vertical Stabilizer, I got started working on the Elevator. Since there are a lot of parts to the Elevator I broke it down into smaller tasks, first preparing the parts of the center counterweight and then I’ll continue next with the other parts of the structures.

So onto another session of preparing the parts, deburring holes and edges and cleaning with Simple Green & degrease with MEK. After that was all done it was back into my small paint booth to prime everything.
Cleaning Station in action Cleaning the Elevator parts with Simple Green Priming the counterweight parts Priming some of the Elevator channels Priming some of the Elevator parts

Riveting the Elevator Counterweight

After all that had time to cure for a day I went to work to put together the center counter balance weight support (that’s a mouthful).
I found a small error in the instructions that say that there are 14 rivets in the center, but it’s actually 16 rivets. Sometimes with these small errors I wonder if they are intentional to keep us builders on our feet to make sure we “measure twice and drill once” – I sent the Factory a note to correct the error in the instructions for the next iteration.

So after I laid out all the parts I put everything together using clecos and the two AN3 bolts and then went to work riveting it together. A friend was visiting from Ireland as well, so after a tour of the garage and everything he also pulled his first rivet and I had him sign his name under it.Parts of the Elevator Center Counter Balance Weight Support laid out Everything clecoed together Done riveting the Center Counter Balance Weight Done Riveting the Center Counter Balance Weight

Rudder Timelapse video

I also recently finished editing together the work on the Rudder, so here’s the completed Timelapse video: