Archive for February, 2006

Baggage floors

Monday, February 27th, 2006

I decided to attach the baggage floors with screws and nutplates instead of blind rivets like the plans call for, so I can put the strobe power supplies under there and still have access later. These are just some "before" photos I took for my own future reference. Looking forward from aft of the baggage bay:

Overhead view of the port side baggage floor:

Looking aft from the area of the pilot's seat:

Overhead view of the underfloor area of the starboard side baggage bay:

I put in the three pop rivets per side that attach the F-750 aft baggage covers to the sidewalls. These covers are already partially riveted in the QB kit, but they leave you these fasteners to put in. I wonder how they thought you'd go about deburring those holes? Luckily, I have this handy Burraway blind deburring tool! It's pretty nifty. You can also see where I got myself with a roloc pad in the die grinder a couple days ago. Gruesome, eh?

Hand deburring bit plus angle drill equals backside-of-rib-flange deburring rig.

Seat back supports / Elevator bellcrank

Sunday, February 26th, 2006

This morning's project was the seat back supports on F-705. I started with a pile of random aluminum:

And, some time later, the seat back supports are built and fitted to the bulkhead. These allow you to adjust the angle of each seat independently.

It's fun making parts from raw stock that's not sized or punched for you, but I wouldn't want to build a whole airplane that way. In the olden days you had to practically mine and smelt your own bauxite – not for me, I wanna fly.

I also spent a quick couple of minutes fabricating the elevator bellcrank. Since I know I'll be installing an autopilot pitch servo, I went ahead and drilled the extra hole in the bellcrank for the servo linkage.

Mary is taking a nap now so I knocked it off with the air tools and the noisemaking and the etc.

Working on aft top skin

Sunday, February 26th, 2006

Here you can see what I was talking about regarding the stringers pushing the F-706 bulkhead out of line. In this photo I've already trimmed them back some, but the bulkhead still has a wave in it from being pressed from behind.

Once the stringers are trimmed and the aft top skin is clecoed in place, the bulkhead becomes straight again. I subsequently trimmed the tabs on the stringers to be flush with the bulkhead flange.

The aft end of the F-688 gusset gets beveled to make the skin lay down against the underlying structure:

Then I drilled the stringers to the top skin. Unfortunately, I goofed one of them up! Somehow I managed to let one of the stringers slip out of position while drilling, which introduced a slight twist over the forward-most few inches. You can see in the photo below that the last four or five holes in the stringer don't have enough edge distance. Argh!

Here's my fix. I unclecoed the forward part of the problematic stringer, clamped it securely back where it needed to be with no twist, and re-drilled the offending holes. This resulted in some elongated and figure-eight rivet holes, so I put in another bunch of rivets, spaced evenly between the problem ones. The result is a strong and straight stringer that just happens to have some doubled-up rivets in the forward part. And of course, me being me, I had to do the same thing to the stringer on the opposite side just to make things come out symmetrical, even though that stringer didn't have any problems. Now it looks like I planned it to come out that way. Yeah, that's the ticket.

Before calling it quits for the day I managed to get the F-6111 stiffeners drilled to the aft top skin. These took a ton of fitting, twisting, fluting, and flanging, but they turned out a lot better than I figured at first. Aluminum really does not want to conform to a funny curve like that without a fight, but I managed to conquer this task. For what it's worth, this forum thread is a good place to start when installing these guys.

You can't really see it here, but I got the F-6111's to lay down against the longerons really well on their forward end. They don't really lay down very well against the bulkhead at the top end, but they fit the skins well, so I'll call this a victory and move on.

Wheels down

Saturday, February 25th, 2006

I discovered that I didn't make the hole in the bottom tailcone skin big enough – actually, I made it plenty big to let the required 7/16" socket get through, but I failed to realize that the tailspring bolt isn't exactly perpendicular to the skin, so the hole should have been one or two sizes bigger in order to let the socket get in there at an angle. No big deal, I just had to dremel the hole into a slightly oblong shape so I can tighten that nut when attaching the tailwheel.

I temporarily bolted on the tailwheel, so that I can use it to make moving the fuselage around the shop easier.

I also knocked together these little legs for the fuselage, and attached them to the wooden spacers that are bolted to the center spar carrythrough:

At approximately 10AM on February 25th, RV-7 #72324 made its first landing! It now sits nice and low so I can just lean into the fuselage to work on stuff. I think those stubby little legs make it look kind of like a KR-2.

Received seatbelts

Friday, February 24th, 2006

My Hooker harnesses arrived today. I went with the five-point system and the rotary buckle. They are wicked looking and certainly seem to be a step up from the stock Van's belts I had in my last RV.

I won't need these for a while, but some folks in the RV community were putting together a group discount and I didn't want to miss out on the deal. Saving 30% made these belts only marginally more expensive than the basic set from Van's. Awesome.