« Archives in February, 2013

Skin and canopy on!

2 hours.

I managed to get home for an hour yesterday from work (yes, still working the occasional weekend) and Dave came over to help me finish riveting the top skin. We got that done, and today, I think I blew my back out trying to get the canopy back on. It wouldn’t slide into the blocks, no matter what, and I couldn’t figure out why. That’s when I had one of those dark moments and issued forth curses and bile.

This is the MGL IO eXtender. It is placed on the subpanel between the instrument panel and the firewall. It is also directly in the path of the canopy frame. In retrospect, I probably should have marked out the 1 3/4″ zone in which nothing should be placed. But I didn’t. At this point, I’m like, whatever. I can move that. I think. Actually, not really. Not too many other places I can put that thing without some rewiring and I wanted the canopy on TODAY. So I came up with this:

Originally, I had a backing plate on the IOX because of the way the mounting tabs worked. Since this thing weighs basically nothing, I’m pretty confident that the arrangement here will be just fine. Now the canopy frame clears.

All that aside, I will be paying dearly for the amount of crouching and wrestling I had to do to get the canopy back on the aircraft. It’s not terribly heavy, but it’s awkward, and fragile, and it took quite a bit of work to get it into place with the hinge pin holes lined up. But it’s now on. When I get back from Seattle, I’ll put the struts back on, and then it’s hurry up and wait for some hangar space.

More skinning.

3 hours.

Dave came over to help me for a bit, and we riveted half the top forward skin on. He had to go and I picked it up after lunch. I managed to get all but the last row, the row along the longeron, and I’ll need some help for that, since it’s inside the plane and I can’t reach it no matter what I try. But it’s almost ready to have the canopy put back on, which is truly exciting.

The Skinner

3 hours.

And yes, it’s a shout out to Neal Asher, whose writing has gotten me through a tough couple of months. When you’re having horrible-seeming things happen to you, reading about truly horrible things happening to somebody else and the truly horrible people who cause them getting their comeuppance is very therapeutic.

As far as this aircraft project goes, yesterday was not horrible. I actually might have the temerity to call the firewall-forward process almost done. The only two things missing from the equation is a 2″ hose clamp for the cabin heat SCAT tubing (which is actually missing, I can’t find it right now) and the manifold pressure sensor fitting and tubing, both on order from McMaster-Carr. I can look at the engine installation and say with fairly high confidence, yes, this engine will turn the propeller repeatedly. Today I’ll go through my periodic shop purge/clean ritual and see if the clamp turns up.

I also took a long look at all the stuff just behind the firewall and ahead of the subpanel, to make damned sure there was nothing else I needed to put there, because as I’ve mentioned before, once you rivet that top skin on, you can’t get to anything below it without a flashlight, a mirror, and possibly tentacles. Satisfied to the limits of my ability with such things, I began riveting the top deck skin on. This is hard. This is hard because you have to have a rivet gun on one side and a bucking bar on the other, separated by a 3-foot sheet of metal and ‘awkward’ only begins to describe the process. There are two holes in the subpanel support capable of taking my hand holding a bucking bar through them, and it’s a little like the reverse of a monkey trap. There is much maneuvering into position, then there is riveting, whilst holding the bucking bar perpendicular to the rivet without being able to see it. This process enabled me to do the center row of rivets, and the canopy hinge support bracket, but failed on the outboard subpanel support rivets because to get my hand into the right position, I had to bend the skin away from the surface it was being riveted to, causing a gap. I couldn’t get the leverage I needed and the skin ‘pillowed’ on the support rib. Bah. Curses. Foiled. I’ll need to enlist a helper for this step, but as soon as it’s done, I can put the canopy back on and officially list the project as ‘more parts assembled than not.’

The endless detailing.

5 hours.

I’m getting real tired of posting about loose ends, but at this point in the build, that’s pretty much all there is. I spent the day safety-wiring and adel-clamping various things firewall forward. Oh, and I did get the blast tubes done for the magnetos and alternator. These are pieces of ribbed conduit that go through the baffle wall and blow air directly on things that tend to heat up. I installed and safety-wired the tachometer drive cap, the oil drain plug, the governor clock screws, and a couple of other odds and ends. Safety wire is crazy stuff and hard to work with, especially in tight spaces, but after a while you get the hang of it.

I secured the wiring bundle on the right side behind the firewall with Adel clamps. It was loosened up to do something, I forgot what.

Oh, and the wonderful news is, we’re now ready to rivet the top deck skin on!

Checklist for firewall forward close-out

Fuel pump overflow tube – figure out how to drain this somewhere that won’t set you on fire. Buy some high-temp fuel line, maybe a flare-to-barb connector.

MAP sensor – Going to need a connection from the port in the center of the sump to the RDAC. Again, high-temp fuel line, and some interesting fun with an angled NPT fitting.

Cooling blast tubes for mags and alternator – still need to drill the holes for the mag tubes, but the hard part is positioning the one for the alternator.

Safety wiring – tach cap, drain plug, anything else I can find.

Back on track.. Kind of.

2 hours.

Been a rough week. A friend passed away last Saturday, so building an airplane has not been the first thing on my mind. Our plan to take my Aliens-dropship-painted RV7 and fly over Detroit playing Front 242’s “Circling Overland” is postponed indefinitely.

But today I got some of the FWF stuff back together. The only fly in the ointment was one of the baffle connecting rods. I can’t find it. With all the moving around of crap to get things out of the way of our downstairs remodel, I think it got put in a throw-away pile instead of a “keep this stuff” pile. I don’t have time to order another length of that crap from Van’s, so I did it oldschool: I used some .041 safety wire with some plastic tubing around it to tie the baffle together. Not bad. The fuel pressure sensor is also done and connected, the throttle cable bracket bolts are safety-wired, and the air intake is reinstalled and safety-wired. I need to spend some time safety wiring things like the oil drain, the tachometer drive cap, and the oil fill tube, but that’s minor.

Then the exhaust goes back on and we do the top deck skin.