« Archives in January, 2013

Fiddly bits.

January 14, 2013 / posted in Firewall Forward, plotting/planning/deciding / No Comments

8 hours.

So yesterday, I joined EAA 723 at Camarillo airport. I dunno why, but I’m drawn to Camarillo. Maybe it’s because my cousin finished and flew that little hot-rodded Vari-EZE out of there many years ago, maybe it’s because it was the first place I took passengers when I got my private ticket, who knows? But I like Ventura county, and I like KCMA. It also doesn’t hurt that the EAA hangar is right near the Commemorative Air Force hangar, where there are a multitude of interesting flying machines to gawp at. Everyone seems friendly, and the guest speaker for the meeting was an FAA official, who gave us the rundown on ramp checks and a few FAR’s that are very much misinterpreted by the likes of you and I.

The goal of this is to find a nest for my bird where I can final-assemble, certify, and test fly 313TD. Currently, there isn’t any room in either of the hangars, but one gentleman is 20 hours into phase 1 on an RV7A and another is getting ready to go fly, so maybe a spot will open up soon.

Another benefit to membership is that the chapter has a flatbed trailer suitable for moving a project to the hangar, which I will hopefully need very soon. Yet another is several more sets of eyes looking at workmanship and assembly techniques.

As for actual work on the plane, I got the left intercylinder baffle and the replacement fuel pump installed, which is nice. All the wiring is re-secured where it was, and the fittings on the sensor are properly installed with thread seal.

Today, the morning was spent with my neighbor’s vast crew-cab contractor truck, schlepping stuff to and from two different Ikea stores, one in Carson, one in Costa Mesa. We’re doing this kitchen remodel, and our designer was a complete monkey: he ordered a ton of stuff we can’t/didn’t use and failed to get a bunch of things we need, so Shelley and I had to kill our morning putting everything right in preparation for the final cabinet install tomorrow.

I did get some work in on the plane, but it’s cold in Los Angeles right now, down in the 50’s during the day. You East-coasters, Northerners and Midwesterners chuckle all you want, but the little space heater in my shop wasn’t able to take the edge off, so it kind of sucked to be out there today. Cold hands bashing on metal structures when wrenches slip reminds me way too much of college street surgery, changing out a part lying on my back under a car in an icy parking lot. One of the many reasons I moved out here and stayed.

So no, it didn’t go well. First event of the day was an oh-shit moment, when I snapped the head off one of the bolts holding the throttle bracket on. That was a study in anger manangement, and I had the presence of mind to self-soothe through the initial impulses of throwing the torque wrench through the sliding glass door. Tantrums do not fix airplanes.

Fortunately, there’s an O’Reilly Auto store not a city block from my house, so I picked up an EZ-Out (sorry, screw extractor- generic) and through some miracle, managed to get the offending bolt out of the sump. I guess I’m now 1 for 5 using those things. At least I didn’t snap the drill off inside the broken bolt like I did with the wing attach adventure from a couple of years ago.

I installed the breather tube and safety-wired the mixture bracket bolts after torquing them with a different torque wrench (A Snap-On dial-type I bought used) and those are fine. I’m hoping I’m nearly done messing around with Adel clamps. Space is getting tight.

More firewall forward progress… And regress.

January 7, 2013 / posted in Firewall Forward / No Comments

5 hours.

The latest load from ACS allowed me to finish a couple of things. I got the oil pressure line/oil line adel clamp securing done, I finished the purge valve bracket assembly, I got the fittings installed on the oil cooler, and I actually got the prop governor installed, and the front center baffle reinstalled. I painted the throttle and mixture brackets and put them back on, and I re-secured the current sensor to the alternator wire. This is where it all went south.

I also finished attaching the fuel hose to the throttle body, and securing it to the intake pipes, but this is where it all went horribly wrong. I had purchased a steel 1/4″NPT-AN6 elbow, but I was using one of the blue aluminum ones to get my fit and mount done. The Floscan is on the firewall, and the elbow points toward the intake pipes on the left hand side of the engine. I had the fuel line connected to this. Somehow, in backing out the AN6-1/4″ NPT elbow on the output side of the Floscan fuel flow sensor, I managed to cross-thread the fitting as I was taking it off. Taking it OFF, not putting it on. So what it did was essentially pull on one side of the threads but not the other, kind of just bending the whole thing. Long story short, I completely destroyed the threads on the Floscan and it will have to be replaced. That was a very expensive ($210 from MGL Avionics) lesson in not connecting loads to dry-fitted NPT fittings loose enough to jam up. I did finally manage to extract the threads left in the Floscan housing and re-tap them, but I don’t trust the connection anymore, especially not with high-pressure fuel running through it. Now would be the time to switch to the Red Cube, except that now I’m reading about failures of these units, plus my firewall mount is drilled specifically for a Floscan. The time for experimentation is pretty much over.

I also got a tube of red RTV for sealing the baffles and putting some blobs wherever things might rub that I didn’t get with Adel clamps.

I still have to track down a hose from PHT (throttle body to fuel spider), but that’ll have to wait until tomorrow. My intercylinder baffles are on their way, and once those get installed I can permanently reattach all the baffles. I can also rivet the firewall to belly skin, because I’m giving up on making an exhaust fairing for now.