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Wiring and fiberglass.

January 18, 2011 / posted in Empennage, Fuselage, Panel / 2 Comments

12 hours.

This is for yesterday and today. I finished up the elevator and HS fiberglass tips. You’ve heard me piss and moan about fiberglass before, so I’ll spare you that this time, but yesterday’s experience was not great. I got the HS off the futon in the other room and set it up on the bench so I could mount and balance the elevators. When I last left the HS, I’d done the fiberglass tips, but I hadn’t done much else with them, and they needed a good amount of shaping before the elevators could swing freely. One side was fine after some filing and sandpaper, the other had the foam too close to the edge so I sanded all the way through the filler and started taking out foam.. This isn’t good. Raw foam isn’t helpful, so I had to mix up some flox, both to fill in the elevator tips after balancing and reinforce the left HS tip. I had this cool thing set up where a thin piece of sheet was curved round the elevator tip, making a form for the flox that would guarantee the free motion of the elevator through its travel.


Would have worked too if the tape hadn’t popped loose, leaving me with a distorted lump of flox on the front of one elevator. I had to file/sand that back into shape, then glop in a load of micro filler to get the final shape.

So there it is curing away.

I busied myself with antenna mounts while the epoxy was setting up. First was the transponder antenna. I’ve decided to put this on the floor behind the baggage bulkhead. All antennae need doublers, even the stubby transponder antenna. The skin of the aircraft isn’t thick enough to provide structure on its own, so I had to take a piece of .063 and make a plate that the antenna can grip onto.



Today I did the final shaping and priming of the HS and elevator tips. While I was waiting for paint to dry, I worked on the doubler for the Garmin GPS antenna.

Installing these doublers aft of the baggage bulkhead is interesting. First thing you do is drill the holes in the plate at four corners, then one in che center. Then you go inside the ship, down the Jeffries Tube, and position the plate where you want it for proper antenna location. Don’t forget to bring your drill. Use the plate as a guide, and drill the skin using the center hole in the plate as a guide. Then measure to square the plate up with surrounding stuff, then drill the corners of the plate. Now it gets fun. You have to dimple all four holes in the skin that match the corners of the plate. You need to use your 3/32″ pop-rivet dimpler for this, but you do it by crawling into the ship, placing the dimpler, getting back out, making the dimple, then repeating 3 more times. In the case of the GPS antenna, there are also screw holes to deal with, which means platenuts. Oh, don’t forget to countersink the skin side of the plate.

Since I was in the tailcone a lot today, I figured I’d do some nagging things I was going to have to do anyway, like the restraint cable clevises and removing the ELT antenna cable. Yeah, can’t run the ELT cable through bulkheads. If you crash, the airframe might fold and sever the ELT antenna cable where it passes through a piece of sharp metal. I decided to run the trim servo wire down that run in its place. Then I ran the transponder antenna wire alongside the two GPS wires on the left side and did the BNC connector.

I don’t want to spend a lot more time down there. It’s cramped, hot, and dusty in there. If I can get enough servo wire slack so I can work on the connector outside the ship, that will make me extremely happy.

The Jeffries Tube.

December 13, 2010 / posted in Electrical, Fuselage / No Comments

3 hours.

In Star Trek, the Jeffries Tube (named after a member of the original series’ production crew) is a long, narrow tunnel from the engine room to the warp drive nacelles of the USS Enterprise. On the RV-7, it’s the space behind the baggage compartment going all the way down the tailcone to the 3rd-to-last bulkhead. Working down there really does make wish such things as aircraft elves existed. Unfortunately, they don’t, so I had to crawl down the Jeffries Tube to drill holes in bulkheads for wiring grommets, carrying a big cordless drill, a bit for the pilot hole, a bit for the grommets, a deburring tool, and the grommets themselves. I was able to get the grommets in and start the wiring run for the strobe cable and tail light power wire. It’s a slow process, and being mildly claustrophobic and crammed into a metal tube reminded me of my recent unsettling, yet action-packed U-boat dreams. I’m going to be spending a lot of time down there. I also have to drill grommet holes for the ELT coaxial cable and set up the wire stays for everything. I’m trying to avoid drilling more holes in the longerons and j-stringers, but I do have some adhesive-backed cable tie holders that will need to be placed.

As an aside, I finished the lower empennage fairing. These two stupid pieces of metal are supposed to have a rubber seal on them, but there’s no way that’s going to fit. Also, there’s no point in making these things removable, so I riveted them on. So now I have a 1/16 to 1/32 gap along the horizontal stabilizer at the root. So I lose a knot. Big deal. If it concerns me later, I’ll create a proper fiberglass lower fairing. Speaking of fiberglass, I got the empennage tips riveted on. they’ll need a coat of primer/paint, but they’re done.

Also, yesterday I got a call from Tim at Tim’s aircraft. My spam filter de-rezzed his pdf of the engine repair estimate, but I got a new one from him. Nearly eleven grand. Ouch. But now I have nitrided steel cylinders instead of that godawful cermichrome and it’s going back together as soon as the magnetos come back from the specialty shop. I just hope he doesn’t flinch at installing the AFP fuel injection system. But what that means, brothers and sisters, is that I’ll probably be hanging the engine in the not too distant future. At this point it’s now time to get down and dirty with the remaining amounts of money and see if there’s enough for avionics, remaining FWF, interior package, taxes, training, and hangar rental at my phase 1 airport.

More emp tips and the strobe head.

December 7, 2010 / posted in Empennage, Fuselage / No Comments

4 hours.

You know by now that fiberglass is not my favorite medium in which to create airborne works of art. Mostly it’s the mess, but the big minus is the cure time. I filled the ends of the empennage tips with foam, laid up some fiberglass on each side to stiffen it, then slathered on a nice frosting of micro. I had to take another run at the micro to fill the low spots, but this time I mixed it a little wet. Of course, this necessitates putting the pieces in a position that will allow the filler to flow out flat along the backside, like so:


This tree, cobbled together with clamps, tongue depressors, and scrap angle, allowed the filler to behave as if it was cast in a mold. There’s still a modicum of shaping after this, but these are nearly done.

But I had to do something else while this was curing, so I tackled the thing I know I have the resources for. A while back, I verified that the strobe unit worked. Now it was time to stick it in the plane. I’m going to worry about wire runs later, but I mounted it just behind the baggage comparment bulkhead on the passenger’s side. This is a fairly common location, and will do the job nicely. But I’m out of practice with metal. I went through three plates before I got one that fit right. There are two pieces of angle a little wider than the strobe head, fixed to the J-stringers between the longeron and the floor. Drilling them to the J-stringers was not fun, and neither was riveting them. But they did eventually go in. Here’s a shot of one of the angles clecoed in:

And this with everything assembled and riveted:

[Untitled]

November 29, 2010 / posted in Fuselage / No Comments

4 hours.

Got the emp fairing done, or at least as done as it needs to be, for now. It needs paint, and maybe another round of micro, but it looks OK as far as I can tell. I had to install the elevators to figure out the control horn cutout, but smart-monkey was in charge instead of impulsive dumb-monkey and I got them perfect on the first try. I got the fairing countersunk, then got the platenuts installed on the VS and HS. Oh, and packing tape sucks. The packing tape I had on the aluminum to protect it from epoxy sticking there did its usual trick and ripped apart when I tried to take it off. A little bit of cajoling with the heat gun and making sure to stop and pull it all off evenly helped. Then I took the tail pieces off, but of course, I forgot to do the lower emp fairings, which I currently can’t find. Next time.

Grumble.

November 17, 2010 / posted in Empennage, Fuselage / No Comments

3 hours.

Aircraft Spruce, for some reason, has twice screwed up getting me my foam that I need to do the empennage tips. OK, fine, plenty of other stuff to do. Like the empennage fairing. This is a fiberglass piece that fits over the place where the tail section is bolted to the fuselage. In theory, you have to pop this on there, drill the holes you need to drill, and fill in whatever gaps are left with flox or some other structural filler. The problem arises when the fit sucks so bad the part looks like it belongs on a different airplane. The only recourse at this point is to start hacking up the fairing and making it fit. Fortunately, fiberglass lends itself very well to this. I had to excise a whole section where the curve of the fairing conflicted with the vertical stabilizer and threw the fit of the whole thing into the toilet. The other thing that had to be done was the part had to be split into two pieces at the front vertical curve. Now it fits. Oh, also, there’s a scribe line around the edges of this part that’s a guide for trimming away the excess. Wish I’d seen that before I started butchering the fairing. With the excess cut away, the fit might have been good enough to just fill the gaps along the edges. I’m tempted to order another fairing and start over. Either that or I’ve bought myself a good 10 extra hours of fumbling around with multiple layups and a crapload of sanding.

But I have to go out of town for five days on business, to rainy, possibly snowy Vancouver BC, so the next chance I get to mess with this thing will be next Monday.

Grumble.

I need five uninterrupted hours to do the glassing. I’m not going to get that.

More odds and ends.

October 26, 2010 / posted in Empennage, Fuselage / 1 Comment

2 hours.

I’m waiting for parts from the Mothership, so it’s all about what I can find to do while I’m waiting. Mostly I sat out there puzzling out wiring runs. The floor panels are in already, so I might have a nice game of Go Fish to look forward to when it comes to running wires for 2 GPS antennae (yes, 2, in case I get hold of a GNS 430W), trim servo, strobe unit power, tail light, then strobe wires forward for the wingtip strobes. What I did actually get done was finally rivet the reinforcing angle that the tank brackets attach to just forward of the main spar. I can’t believe I forgot to do that during wing mating, but I think I probably had other things on my mind at that point. So that’s done, and there are little blobs of torque seal on the accompanying thru-bolts to tell me I don’t have to worry about it anymore. Oh.. remember this thing? F-697?


It’s the canopy jettison bracket. I put it on the subpanel because I was just following the directions. Then I realized I’m not going to install the canopy jettison system (weight, complexity, etc). Now I realize that thing might get in the way if I have to chop holes in the subpanel for some deep avionics, like a GNS 430W or some other surprisingly large piece of gear I think I need. So I took it out. You can never have too much practice drilling out rivets.

After that, I fiddled around with the fiberglass rudder tip, and worked on the mounting system for the tail position/strobe. This is genius. At some point, I bought a length of 1/4″ aluminum dowel from the hardware store. What I did was cut 2 half-inch lengths of it, which I’ll drill and tap to 4-40, the same thread as the tail light mounting screws. I’ll put some dimples in the sides of them, then sink them into blobs of flox in the rudder bottom. At that point, they’ll be permanently affixed and I’ll still be able to unscrew them to change bulbs. OH, thumbs down on the build quality of the rudder botttom. The two halves of the rudder bottom don’t exactly line up along the seam, so I’m going to have to clean it up with micro and sandpaper. If I was exceptionally skilled with sheet metal, I’d make my own out of aluminum, but I’m not, so I’ll deal.

Finally, I messed around with the tailwheel springs. I’m going to need to order new chain. I should have looked at the plans. I remember them going together completely differently, and it took me some time to figure out that getting the chain directly on to the spring is no big deal. But the puzzle fooled this monkey, and I missed ‘Castle’ for nothing.

I’m going to pester Tim again this week and see what the deal is with my cylinders.

Let Them Eat Static.

September 14, 2010 / posted in Firewall Forward, Fuselage / No Comments

1 hour.

Finished installing the static line. Much easier to crawl down the Jeffries tube with the flap motor bracket removed. I also made some .063 spacers for engine mount. Supposedly they weld it all up in a jig at the factory, and drill the QB fuselages with the same jig, but maybe the welding process stretches the metal a bit. Anyhoo, I had to make two aluminum washers to go behind the lower middle attach points, which, fortunately, are about .063″ off the firewall when the 4 outside bolts go on. They’re probably not exactly .063″, but they will be when everything is tightened down. I have a good feeling about it. I also got out the fiberglass cap that goes on the bottom of the rudder to see how it might accommodate the Whelen A500 position light/strobe assembly, and the answer is: not that well. There will be a need for fiberglass work here, I think. I’ll have to somehow build up enough material to drill and tap threads, or I’ll have to figure out a way to get a backing plate in there. Neither option looks like fun, but there’s gotta be some light back there or we ain’t legal. I know I promised photos, but I forgot to bring my phone. I’ll catch up with that later.

Back to the fun stuff

September 13, 2010 / posted in Firewall Forward, Fuselage / No Comments

4 hours.

Saturday and Sunday were somewhat unproductive, given the gloom-induced malaise and subsequent need to eat (organic) cheese puffs and watch TV, but I installed the VA-168 sensor manifold, the cabin heat box, and most of the static line. The sensor manifold and the cabin heat box will have to come off and get fire-sealed before I can call them done, but I need to find an acceptible fireproof sealer for the various firewall penetrations first. If everything works out right, I won’t have too much going through the firewall. Right now, I can think of some: For holes in the firewall, I’ve got 3 control cables, the brake line fittings, the fuel line fitting, cabin heat, the RDAC (engine sensor pod) cable, main bus power, brake cylinder fitting, and the various bolts holding things on. Fewer pass-throughs sits well with my universal hate for goop of any kind. But the idea is to keep windblown flames from burning avgas, smoke, and carbon monoxide out of the cabin. Dead pilots make bad landings. The 2″ hole for the cabin heat box was less traumatic than I thought it would be. I used a 2″ hole saw on a cordless drill at the lowest speed and plenty of Boelube. The trick with stainless is to go slowly and keep it as cool as you can. If it heats up, it hardens, and it will kill whatever tool you use on it. But care is needed: stainless steel makes an extremely sharp edge when cut, and it’ll go after you with near-sentient aggression. File down the edges, or pay for it later in blood.

The static line is still unfinished. I fabbed a bracket for the T-fitting that joins the two lines from the static ports on either side of the fuse, and I drilled a hole in the angle where the canopy latch bar attaches so I can run the tubing up under the left side longeron on its way to the EFIS. I got the cable clamps installed along the bulkhead, but I haven’t yet installed the bracket for the T-fitting or cut the tubing to length. I also wound up removing the flap motor because there’s no good way to winkle my big ass into the tailcone without some pretty decent contortions. I’m not a huge guy, but I’m not as limber as I used to be, and I have a somewhat irrational fear of getting stuck in a position that cuts off my air supply or leaves me unable to extricate myself without assistance. Once I’m prone in the tailcone it’s fine, as long as I remembere to bring all my tools and parts with me. The motivation to plan the job ahead of time is amplified hundredfold by the sheer amount of work it takes to climb into that space. Oh, and also to remember to go to the bathroom before you get started. I’ll post some photos tonight or tomorrow.

More odds and ends.

August 30, 2010 / posted in Fuselage / No Comments

5 hours.

Mostly a cleanup day. And a rearrange day. And a figure-out-what-to-do-next day. So there was cleanup. I rearranged the guest house bedroom and gained back a few more precious square feet. Then I went over the construction manual and checked off things I know I did but didn’t check them off during the actual work, mostly from wing mating. After that, I screwed the panel back on and started tinkering with the throttle quadrant. I didn’t get far with that. I needed to get the canopy out of the attic. It was beginning to drive me nuts that it was sitting up there, with the spiders and the heat. So I brought it down and then I realized I’d never put on the canopy latch handle or the outside canopy lift tabs. Not fun, but necessary. I hate cotter pins. I got the handle and tabs done, then had to take the canopy off and put it up in the rafters of the main shop. It’s pretty empty right now. More parts are on the plane than off it, at least parts that came with the kit. Oh sure, there’s lots of fiberglassing to be done on the empennage tips, wheels, landing gear etc.

But I’m at a crossroads: What next? leave the airframe for a while and do the O- to IO-360 conversion on the engine? Order avionics and start wiring? Or just do it all. Go to town. Work on the wiring while i’m waiting for engine parts and vice versa. But something tells me I’d rather not have nasty stripped-down engine between the plane and the workbench for extended periods of time unless that’s all I’m working on. Engines can be whole projects in and of themselves. But the truth is, if I find enough nastiness in the engine when I pull a cylinder off, it goes bye-bye to be rebuilt by real engine builders in real shops. If not, I replace cylinders as necessary, install the hi-pressure fuel pump, the new sump and tubes, the AFP FI system, and bolt it to the airframe. Fortunately, I’ve got all the parts for that, I think. I need to make a checklist for incidental parts, like hoses and gaskets, other stuff like that, and order it in advance. I also have to be singularly anal about the teardown process and not lose ANY PARTS WHATSOEVER and adhere strictly to the manual. This is no Oldsmobile Rocket V8.

Wing work wrapped up.

August 16, 2010 / posted in Fuselage, Wings / No Comments

4 hours.

Finished the platenuts in the left wing. Other than a slightly messy install of the trailing edge platenut, the process went OK. However, for the first time, I regret not getting the platenut jig for the 8-series K1000 and K1100’s. I still have to figure out what to do about the wiring that’ll eventually go through the fuselage to the panel, but I there is no longer any interference with the control tubes (yeah, that was a big one, glad I caught it now). The wings are now back in the little garage for storage until they go to the airport.

So what next? The engine is supposed to be next, but I need the space and tech to fix a busted motor mount on my Buell, which is my daily transportation. However, I am dying to find out just how bad my motor is inside. Here’s hoping the guy who stored it for 10 years stored it properly and I don’t have a rusted camshaft.

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