N254MR

In March '08 I got the idea that maybe, just maybe there were few enough tasks left to do that if I listed them, with reasonably realistic granularity, the size and scope of the list wouldn't be too daunting. I came up with about 70 items, and it didn't seem too bad. It was organized in sections for A) before first engine start, B) before airworthiness inspection, and C) before first flight. Since then, I revised the spreadsheet once, in May, and finally got around to looking at it again today. Incredibly, I was able to check off ("X") a whole bunch of things, most of which hadn't even been started back in March. What a great feeling! I did add several more lines with tasks I'd forgotten to put down, or more granularity -- but still, it's incredible to realize that I actually have made progress after all. I wasn't going to post this before... now. 

The task list spreadsheet is now in the Library, Project Documents, Checklists... section, here.

Today I got a start on a ground wire for the AeroCarb. The existing ground wire from the original Bing carb wouldn't work because it had the wrong type of termination needed on the carb end. There is a quick tab junction in this wire to make it relatively easy to remove the carb. However, that's on hold waiting for parts. (Can't believe I didn't have that!)

So it was on to working on the CHT (cylinder head temperature) probes. First, as recommended by Jim McCormick at Jabiru Pacific, I drilled a tiny hole in the top aft corner of the top fin on each cylinder for a place to secure the wire. Then I went through various attempts to mount the CHT rings again one a plug, in a plug "well" but found that my original metal grinding/cutting to create space for  the CHT probe "stem" or "shank" was insufficient. It turned out more aggressive metal removal was needed to get the probe to seat properly without breaking. The CHT probes are surprisingly fragile when bent. Yes, I did torque this plug down to 11 Nm (8 ft.lbs.) before adding the tie wraps. If I need to remove compression, I'll pull the front plug in each cylinder. It ended up looking like this:

Here's another, more close up view of the metal removal and positioning:

And a final shot of the finished installation on cylinder #4:

After another two hours, the right side mag (coil) terminations are done. Room to flex, but tight.    At the top center, just right of the white engine mount, you can see the bolt for the main engine ground cable isn't tightened down. It's waiting for an 11" braided ground strap that will go toward the right, to the front side of the starter housing.  Grounding both ends of the starter motor has been shown to reduce ground path resistance, keeping the starter motor noticeably cooler. The name plate of the B&C SD20S auxiliary alternator is visible at the lower left corner of this photo.

Finished the left mag coil wire this morning -- it took two hours. Actually, more like three. First we see preparation of the wire, showing how the shield of the mag wire is tapped out to the black wire using a RayChem solder sleeve.

Next we see the finished mag wire, with much heat shrink for strain relief.

Finally, the whole wire assembly is connected to the left mag's quick tab, and the black wire (wire shield) is connected to engine ground via the mag mounting bolt. The black mag wire has clear heat shrink to beef it up. A drop of blue threadlock was added to the bolt.

Made some progress on the oil pressure and temp sensors. At the lower left, yellow and black heat shrink close off the main high-temp, fire retardant loom from the firewall. The various leads are in various stages of completion, but almost done. Each individual wire is also enclosed in a smaller loom, and copious amounts of heat shrink for strain relief in this high vibration area. Sprouting up to the right is the quick tab connection for the Jabiru oil pressure sender, which mounts on the forward one of two pressure ports, post cooler and filter. It provides analog pressure signals to the EFIS. The EFIS will be programmed to generate alerts at low and high levels. Further up are three wires for the B&C S8012 oil pressure switch, which occupies the top port, before the oil filter and cooler. It has both normally open (N.O.) and normally closed (N.C.) contacts. The N.O. close when the engine runs, and activates the Hobbs meter. The N.O. contact closes when oil pressure fails, triggering a blinking red annunciator LED on the panel, right in the pilot's straight ahead sight line. The EFIS will give first inidications of dropping pressure, and the LED annunciator, driven by the B&C normally closed contacts, will signal that oil pressure has failed, and the engine should be shut down ASAP.  (Click "Read More" below the photo for the rest of this post and more photos.)

In a couple places I have double MS21919 "Adel" clamps to hold wire bundles, etc., in the FWF area. One such location is shown below, where I have to hold the wire bundle (engine ground, starter, alternator connections) up as it crosses over the mixture cable -- the location of which takes precedence. Holding the spring steel of the clamps in a compressed state long enough to get washers and a nut on the bolt is not easy with your bare hands. This is the kind of thing that will be obvious to most people, but... eventually I figured out (duh?) that the needle nose Vise Grip (tm-no doubt) is the ticket. One side of the needle jaw clasps the bolt head, and the other grabs the edge of the bottom clamp face, exposing the bolt threads, at least long enough to get a washer and nut on them. Obvious? Probably. But now you won't ever have to admit that you didn't think of it on your own.

Hasn't been easy to get back to work after Oshkosh. Life (mowing, floor cleaning, computer repairs, etc.) interferes with art -- again!    The fact that what I have to do first is 2-3 re-do's makes it that much harder to get started, but....

Yesterday eve I got back to the FWF wiring, which meant breaking down the AC side of the alternator circuit (which had been closed up) in order to connect the tach RPM sensor to one of the AC wires -- which should have been included before! It's there now! Tonight I got the ammeter shunt and Jabiru regulator positive & negative outputs wired, to its filter capacitor and ground, respectively. Tomorrow I'll finish the B&C alternator field circuit and both filter grounds, and re-do the sleeving for the vertical bundle going down to the fuel flow & pressure senders with a better, flame retardant chafe sleeve.

At long last a slideshow function has been added to each of the "new" (post-mid-2007) galleries, allowing viewers to see a lively presentation of the images automagically. I've also added a link to allow easy one click emailing of a page, if you want to send it to yourself or someone else who may be interested.

I hope these additions will make the site even more useful and enjoyable. As always, your comments are welcome.

After trekking to Oshkosh once again, and catching up on numerous househld chores, it's finally back to work here. First task was to finish mounting the flap controller. Because the flap controller will now be mounted upside down under the relay shelf, and because the bottom (now top) of the controller is just open, exposing the circuit board, I made this insulating mount out of some thin acrylic board. There are a couple of machine screws above this location (going up into the shelf) and, although it's highly unlikely any of those would drop out -- if they did it wouldn't be good if they shorted traces on the circuit board. The acrylic standoff will preclude that possibility while still leaving ample ventilation gap space at the sides.

It may be worth mentioning again why this site exists. First of all, it's the primary documentation repository for the project. Such records are important to have in support of certification, to assist future maintenance, and possible resale. Second, it's a source of info for others who may be interested in building any airplane, Rebels in particular.

So far, the site has functioned better than I had hoped, on both counts. It's relatively easy to search the annotated entries for information, whether in the blogs, galleries, or library, and I've been gratified by the many people who have contacted me with questions and comments about the processs. Some of them are now good friends, from whom I've been privileged to learn much in return.