Trailing Edge | Andrew's RV-7 Build Log

Made a Decision on the Rudder

August 12, 2010

Disclaimer: My favorite tag for today’s post is “Boo Boo boom boom airplane go fly.” Read on.

Well, after much soul searching, and some really helpful advice from VAF (thread here), I’m going to drill out the skins, inspect for any internal damage and rebuild the larger rudder.

Favorite quotes from the thread:

I did the SAME EXACT THING as you did

I dropped a completed fuel tank while moving it from one storage location to another.

My two year old daughter says “Boo Boo boom boom airplane go fly” while looking at your rudder. I am so proud!

I forgot the fiberglass tips were on and unsecured. He picked up one end and –crash!

I banged up my rudder too.

Don’t feel bad – I had to build a whole second set of ailerons when I built them both backwards, at the same time (DOH!)

Your new rudder will be better than the old one.

Although I got my hands on a set of RV-8 rudder preview plans, and a lot of the parts are common, I just don’t want to mess with doing a large flight test spin program just for aesthetics. It just doesn’t seem like the right thing to do.

While I could probably say I’m not going to intentionally spin the airplane, I probably will want to at some point, and I’m really worried about having a botched aerobatic maneuver (too slow during a hammerhead turn), and falling off into a spin from which I’ll have a hard time recovering. In that case, I’ll want the bigger rudder.

Also, I would feel guilty ever selling the airplane, especially if (god-forbid) anything ever happened to a later owner.

So, rebuilding the larger rudder it is. And besides, my trailing edge is going to be perfect this time.

But, in the meantime, I want to set the new standard in “finished empennage pictures.” Maybe this new standard will keep someone else from damaging their airplane for the sake of a stupid picture.

Done with the empennage!

Now where is that wing kit?

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2 Comments | Empennage | Tagged: aerobatic maneuver, Boo Boo boom boom airplane go fly, flight test spin program, preview plans, Rudder, RV-8, Trailing Edge, VAF | Permalink
Posted by Andrew

Bent Left Elevator Trailing Edge

June 2, 2010

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Sick again today, but I did get a little work done.

First, I spent a considerable amount of time looking at the 4 horizonal holes below. The plans show them as blind rivets, but there has to be a way to get solid rivets in there.

After much deliberation, I think if I drill them to #40 now (gasp, without matchrilling!?) Then I can deburr, scuff, and dimple the area now. I’ll do the same to the equivalent holes in the trim spar, and then attach (at a minimum) the top skin to trim spar holes with solid rivets. I think I will be able to get both sides, as I am planning on cutting off the “bent tabs” from both the elevator and trim tab.

First, drill to #40.

Then, deburr interior and exterior, and scuff the interior only.

I got the c-frame out again and dimpled the holes.

I should be able to make that work out for me, but more on the bent tab cutting later on.

Next up is bending the trailing edge. After inserting and taping a 1/8" dowel in the trailing edge, I bent it in my bending brake. This picture is about halfway bent.

Then, I removed the dowel, bent it the rest of the way, and did the same with the trim tab since I was in the bending mood. (Side note, the trailing edge on the elevator looked great, but was not constant radius…it was larger radius toward the tip. I grabbed the hand seamers and gently squeezed the areas so they were all the nice crisp radius that the inboard trailing edge was.)

Trim tab bent.

Also, I way overbent the trim tab. There are no stiffeners in there to stop you, so you can basically flatten the thing, even with the dowel rod in there. I opened it back up a little by hand, but it’s not perfect. If I can’t get it back to perfect, I’m going to order another one. I think I can work with this one, though.

This is a radius shot of both the elevator only.

Here's one with the tab held in place. Looks good to me.

Another sickly hour today. Can’t complain.

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Leave a Comment » | Empennage | Tagged: bending brake, bent tabs, Blind Rivets, C-frame, Deburr, dimple, dowel, Elevator, scuff, solid rivets, Stiffeners, Trailing Edge, trim spar, trim tab | Permalink
Posted by Andrew

Trailing Edge Angle Work

March 27, 2010

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I didn’t get in a lot of work today, but an hour on the trailing edge isn’t too shabby.

First thing, unpack the Lowes bounty. I picked up a 6′ piece of aluminum angle (for the trailing edge work) a long (36″) backriveting plate, a 36″ 3/4″ diameter steel stake for leading edge rolling, and a smaller backriveting plate that I will be returning (picked that one up before finding the longer one).

Lowes bounty.

I grabbed the aluminum angle, and drilled both sides to the dirtier side of my MDF toolbench.

The cleco on either end will help it stay put.

Then I used the trailing edge (pre countersunk) to drill the trailing edge hole pattern in the aluminum angle.

I lined up the trailing edge with the aft edge of the angle so I could ensure things were straight both left and right and forward and aft.

Here’s the angle after being Matchdrilled.

Let's do it.

Next up, countersinking the trailing edge wedge to accept the dimple of the skins. I grabbed a piece of stiffener (.016″) and used my standard dimple dies as a test piece. First, I measured the very outside diameter of the dimple.