Archive for the ‘Fuselage’ Category

Made rudder stops

Sunday, September 3rd, 2006

If I worked at a real airplane factory, I'd get fired for taking like eight hours of work over two days to make these stupid little rudder stops. Of course it doesn't help that the design requires each set of stops to be tailor-made to the individual aircraft. I spent a huge amount of time measuring, making and discarding test pieces, and fiddling around with templates. Out of absentmindedness or frustration I forgot to take any photos of this process, so here's a shot of the first rudder stop I was able to produce that actually fit:

You can see that I've temporarily installed the rudder cables to make sure that the rudder stops and cables don't get tangled up at any point along the full swing of the rudder.

Here's an overexposed overhead view showing the angle the rudder horn is at when it hits the stop. Lots of cutting and filing to get to this point.

It means nothing unless it has that swing – when the rudder hits the stop and the elevators are neutral, it's just a shade over an inch from the rudder to the inboard corner of the elevator trailing edge. Plenty of clearance to keep the tail surfaces from banging together, and slightly more travel than is called for in the plans. Extra rudder travel is good, it means extra rudder authority. I've heard of some people making this dimension more like 1/2", but that seems like cutting it bit fine to me.

After I was finally satisfied with the fit, I rounded off all the corners and made the stops look pretty, and countersunk the rivet holes. These two I was able to do with the countersink cage; for the two that are closer to the flange, I used this setup to make the countersinks freehand.

I primed the stops and the skin underneath, then riveted them halfway on. The plans call for CS4-4 blind rivets in the front two holes. I used CherryMax CR3212-4-4's instead since I have a whole drawerful; the literature says they are something like 3x stronger in shear. The aft two holes will have to wait for now, since I can't squeeze those rivets until I remove the vertical stabilizer.

This photo is to remind me that I haven't torqued any of the control surface jam nuts yet – my torque wrench has a 1/4" drive and my crow's foot wrenches take a 3/8". Time to go to Sears!

Worked on seats

Saturday, August 26th, 2006

This morning I fitted the required hinges to the new seats:

Really astute observers may notice that the hinge arrangement with the Classic Aero Aviator seats is different from the stock Van's seat backs. These seats are actually interchangeable between left and right, where the stock seats will only fit onto the floor hinges one way. Don't worry, I measured multiple times and this really is how it's supposed to go in order to center the seats on the control sticks.

Then I drove out to the other side of the KC metro to go to the Grain Valley (3GV) fly-in. Here's a photo of RV-9A builders John and Martha checking out a possible paint job:

In which the author has a seat

Tuesday, August 22nd, 2006

I cam home tonight and was surprised to find this big box from Classic Aero waiting for me on the porch. I opened it up to find…

Seats! They look really great. The quality appears to be outstanding.

I sprung for the fancy Aviator seats, which have adjustible lumbar supports. Gotta be comfortable when flying. These are the adjusty-knobs on the back.

Each seat has two booster cushions. We'll see, eventually, how well Mary is able to see over the nose. It may turn out that we need to add some extra cushion stuff for her to see out. Luckily Classic Aero said they'd be happy to make up some extra booster cushions if we need them.

And I even like how the colors turned out. I can't wait to sit in the fuselage and make airplane noises.

I got the seats a little earlier in the building process than most other folks seem to do, but I wanted to have them in place for fitting the rudder pedals and other stuff like that, so the airplane will be exactly set up for how I'll want it when I'm flying it.

Odds and ends

Sunday, August 20th, 2006

We were entertaining guests most of the weekend, so not much progress to report on the plane. I did a few miscellaneous things, though.

I made up the low-pressure hoses that go between the brake fluid reservoir and the passenger's brake pedals. These will have nothing but ambient pressure in them, so even my mediocre hose-making skills were up to the task. I decided to have all four of the high-pressure brake hoses professionally made, however – a real hose shop has better tools to assemble and test hoses than I do. For my own future reference, I'll need two 36" -3 size and two 16" -4 size hoses.

In order to estimate the required hose lengths, I had to figure out roughly where and how the parking brake valve will be mounted. So, I made this little standoff for it out of some hat section material I got from Van's a while back. This will get riveted to the firewall later. I used nutplates here on the assumption that it would be a pain to get nuts onto the back of this once it's installed.

Then I spent a bit of time making reinforcements for the armrests. On my old airplane, both armrests were sagging in the middle after a couple years' worth of use. On this plane I decided to rivet on some aluminum-angle doublers to stiffen them up a bit. I used my rivet spacing tool to mark out the rivet holes:

The 0.032" angles are oriented flange-up, thus making a sturdy C-shaped section where before there was just a single bent flange. This view is looking backwards from the forward end of the armrest, which is noticeably sturdier with the angle clecoed in place.

I dimpled and deburred the angles and armrests – the Burraway tool was handy for deburring the holes in the already-installed pieces – but I didn't rivet anything in place just yet. It turns out that the reinforcement angles block access to a couple of the rivets that will eventually hold the F-704K's in place, so the angles will go into the parts box until they're needed.

Finished empennage attach

Saturday, August 12th, 2006

Today I took the empennage stuff completely apart yet again, deburred and cleaned everything, and primed the various parts that needed it:

I also vacuumed out the tailcone and smoothed and spot-primed a few places where there were scratches and tool marks.

Once the primer was dry (it doesn't take long in Kansas in the summer) I riveted the up elevator stop to the top deck:

I also riveted the forward attach plate and shim to the vertical stabilizer spar:

Scott came by to check out the project and I put him to work bolting the tail back on yet again.

Since all the bolts are in now, I attached the tailwheel. Once I'm done with rigging the control surfaces, I'll take the tail off and put it back in storage, but I should be able to use some shorter bolts and a temporary doubler of some sort to keep the tailwheel fastened to the aft bulkhead.

I installed the F-790 aft elevator pushrod and rigged it so when the elevators are clamped in trail with the horizontal stabilizer, the elevator bellcrank is exactly vertical. This happens when a 3/8" socket placed over the lower bolt head is perfectly centered in the access hole, like so:

Just for grins I also installed the F-789 forward elevator pushrod to see how it would fit. Something seems to be wrong, though… In this photo the elevators, bellcrank, and control sticks are all in their neutral positions, and even with the rod ends backed out as far as I dare, the forward pushrod is way too short. I promise I made it the exact length called out in the plans, so I'm not sure what the story is. It may turn out that I have to re-make that pushrod, which is no big deal since the end fittings are not terribly expensive and the tube stock is available locally – no expensive shipping of long pieces, hooray.

I also spent some time cleaning up the garage, which was a mess. It's still a mess but at least most of the tools are put away now.