« Archives on August 3, 2010

Um.. Dude… There’s an airplane in your backyard.

August 3, 2010 / posted in Fuselage, Wings / 1 Comment

10 hours.

This Sunday was a huge day. I got up the nerve to put the wings on for alignment and some other ops that necessitate having the wings mounted. The way this works is that the wings are some thin aluminum skins wrapped around a thin aluminum skeleton that’s attached to a thick, beefy wing spar. The end of this wing spar sticks out at the root and slots into the thick, beefy center section of the fuselage. This is held in place by a fistful of close-tolerance bolts. For this fitting, I’m not using the close-tolerance bolts, I’m using drift pins made from 7/16″ hardware store bolts, like so:

gloss check
You can see here I made 8. I only need four, so if anyone needs some 7/16″ drift pins, holla. With these, the threads get cut off the end, then the end gets rounded. Then the wing spar finds its way into the center section and these go into the attach holes.

Not sure how much you remember about the configuration of my workspace, but one thing of particular interest is that the patio door is too narrow to accept the fuselage of an RV-7. I found this out way back when I took delivery of the QB kit, and just as then, I had to take the patio door off. Sliding glass doors suck. And they’re heavy. And they only get worse with each consecutive removal and reinstallation, so I’m looking at options, but that’s a digression.

fuse on wheels
I didn’t have the fancy lift-dolly the driver had when he dropped off the kit, so I had to fall back to that ubiquitous artifact of modern suburbia, the furniture dolly. I got the last two from Home Depot yesterday, and extended them with some scraps of furniture-grade plywood we had left over from a project. Fortunately I can still lift the canoe on my own, which I did while Shelley wrangled the dolly under the sawhorse up front. The back end was much easier, since it doesn’t weigh much at all.

ready to go
sliding door off, fuse on wheels. Don’t get too comfortable, Simba. You’re on the taxiway.

outside
We did it! Shelley’s happy to see this thing out of her craft room, even if only temporarily. But now we have a problem. Those wooden planter boxes to Shelley’s right are in the way of getting the left wing to where it needs to be for fitting.

wings on cradle
That just ain’t gonna happen. So the planter boxes need to go. Shelley wanted to take them out anyway, to give us more yard. Well, dirt at the moment, but yard eventually.

box demolition
So Shelley and I demolished the planter boxes. Chicks with air tools are teh hawt!

left wing on
Here’s one with the left wing on. Hey. Psst. Did you forget anything? Oh yeah! Drawing 38, cut down the rear wing spar tabs as shown, so there’s enough clearance to set sweep and incidence. Left wing came off shortly after this photo and the appropriate adjustments were made.

both wings on
Yeah! Now the fun begins. Measure, level, measure again, level again, measure some more, drill.

chickens
Take note, chickens. This machine here is the only way either of us will take to the skies, and the only way you’ll be using this one is if you’re in the middle of a sandwich or deep-fried in a bucket.

But wait, there’s more.

August 3, 2010 / posted in Fuselage / No Comments

Not over yet. The canopy is still draining the life out of me at this point.

gloss check
After sanding the fillet as smooth as I could with progressively finer swatches of sandpaper, I couldn’t really tell except by feel whether or not something was smooth, so I threw a layer of gloss white on it. The point of this is to see how warped the reflections are, and to see if there are any egregious spots that need attention. And yes, there are.

gloss check
The fillet looks OK. After this was a lot of cleanup and cosmetic filling. Remember, kids, flox is structural, micro is not. With the layers built up as well as they were going to be, I switched over to microballoons and resin for final shaping. Microballoons are microscopic spheres of glass. You mix that with resin, adding micro until its the consistency of peanut butter. You want the little peaks to stand up on their own, because if they don’t, the mixture runs when it’s on a vertical surface and that’s bad. I did about 5 or 6 iterations of micro and sanding before I remembered I wanted to fly rather than build.

Some old business.

August 3, 2010 / posted in Fuselage / No Comments

Remember how I said I wasn’t going to give you a play by play of all the iterations of goop? I lied. Here’s some pics of the process.

First round of sanding. This is just the black flox-resin buildup. I grabbed some stiff foam pipe insulation (redneck water noodle), a section about a foot long, from the hot water recirc pipe on the side of the house then wrapped it in sandpaper, which gave me a flexible sanding block with about the right radius for the fairing.


A few rounds after this point, I was ready for some glass.


Here are two of the strips of crowfoot laid out on the plastic, getting ready for wetting.


Yes, it is actually me building this thing.

The black electrician’s tape is the point at which I’d like to stop getting fiberglass goo all over the skin.   Forward of this,  I covered it with clear packing tape, which was a HUGE mistake, or at least it’s a huge mistake to use the cheap stuff.   I wound up picking most of it off with my fingernails in a time-consuming, arduous process that I’m not eager to repeat.   Word on the street is that the black vinyl tape plumbers and HVAC guys use (not duct tape) is perfect for this.  It also takes a couple of hits from sandpaper without turning into a scored mess.

Another shot of me.   Are you not entertained?

This time, I put the peel-ply on in little strips, which yielded much better results than trying to wrap long strips of dacron around that compound curve.

This shot, you saw in the last post.   This is after glass and before the next layer of flox, used to fill the divots.   After that layer, I switched to micro.   All of it tinted black.. Nasty stuff.