Sunday, September 23, 2012

Cleaning up the rats nest

I spent a few hours working through the punch list. One of the first things I wanted to do was clean up the wiring. The stuff in the avionics bay wasn't bad, but could be better. The stuff in the tunnel was a nightmare. I got off to a slow start, though, when I couldn't find the step stool needed to get in and out of the plane when the wings aren't on. It didn't take long to find, but it did remind me that the actual steps were not yet installed. I took care of that, and will surely regret it as I begin the long, painful process of learning not to bark my shins with them.

I disconnected roughly half of the J-box connectors and re-routed some of them. There were still a couple of bundles that were in need of some tie wraps to keep them nicely collected. I gave myself a bit of a scare, though. I though it would be a good idea to turn the Skyview on when I was done to make sure that I hadn't broken anything.

 TRANSPONDER FAIL! Uh-oh!

I removed the transponder connector to make sure none of the pins had been bent. It looked fine. I tried re-seating it half a dozen times to no avail. Finally an inspiration struck me: how about trying it with the Avionics switch turned on? That did the trick. So, mental note: the transponder only works when the Avionics switch is turned on. Imagine that!


The tunnel was a much bigger job, due both to the extent of the mess and the awkwardly inconvenient work location. Just getting the various wires untangled enough to allow them to be bundled and restrained was a herculean task. It looks a lot better now, but at the end of the day I probably made it look better at the cost of having introduced a plethora of sources of the type of spurious electronic interference that will drive me nuts for the next five years.


I had hoped to get the throttle and choke controls installed, but by the time I got that *&^@#$ heater cable put back in I had had enough. I did manage to get the cables pushed through the panel and firewall, but the business ends of them are just dangling out over the engine.


Saturday, September 22, 2012

The Shocking Secrets to the Art of Wiring

As you may recall, I mentioned a couple of problems I was having with the headset jacks and the comm radio. The problem with the headset jacks was mostly notable when trying to use the headset microphone on the pilot's side. As I talked into the mic, all I could hear passing through the intercom was a thin, weak, scratchy sound - nothing at all like a voice. When I keyed the mic to talk on the comm radio, it was even worse. It basically shut down any sidetone. The sidetone is what allows you to hear yourself talking on the radio and is critically important. It is so loud in the airplane while flying that you literally (in a non-Biden sense) can't hear what you're saying. If you've never had that experience, you would be surprised at how much difference it makes to the clarity of your speech. And in flying, it's pretty important to communicate clearly with air traffic control.

There are four primary causes to electrical problems, each having its own rule:

  Rule 1: wires cannot have breaks in them.
  Rule 2: wires must be connected to the correct endpoints.
  Rule 3: wires that should go to ground must go to ground.
  Rule 4: wires that should not go to ground must not go to ground.

I started my troubleshooting by verifying that the mic wire met rules one and two. I pulled the plug that contains the endpoint of the mic wire out of the J-box, plugged a spare pin into the correct hole number as shown in the plans, attached one lead of a multimeter to it, then attached the other lead to the mic jack in question. Fully connectivity.  That left rules three and four.

To determine if the jacks were grounded correctly, I went back in the plans to review the installation instructions.  From my review, it looked like one of the jacks was supposed to be grounded to the airplane via the simple method of being in contact with the floorboard. I inferred this from noting an 'isolator washer' on only one of the two jacks.

Hmmm, two potential problems here. The first was obvious: note that the isolator washer is on the outer surface of the floorboard. That implies that the part of the jack assembly that needed to be grounded on the other jack should have good, clean contact with the floorboard. And here's the problem with that: I had painted the floorboards before installing the jacks. There was a thick coat of paint separating the jack and the metal of the airplane. I would need to remove the jack and clear some of the paint off so the jack could get a good ground.




When I removed the jack, I found the second problem. I had installed isolator washers on both the audio and the mic jacks, probably because Van's gave me four of them even though I only needed two.  I had one too many on both sides of the plane. Out they came!


I powered up the plane and the problem was solved! I was able to get a clear, strong voice signal through the intercom from both the pilot's and copilot's headsets.

The problem with the comm radio persisted, though. I pulled out the installation manual for the comm radio to check up on a lead I had gotten from Jackson: there was rumored to be a configuration setting in the radio to adjust the volume of the sidetone. It didn't take long to find, and it was a pretty easy thing to do. Garmin ships the radio at the middle level volume setting, but it's a simple matter to adjust it. You just press and hold the 'MON' button for a couple of seconds, use the large knob to cycle through to the 'SIDETONE' page, and adjust the number up or down. Garmin had set it to a value of 128 (out of 255) and I lowered it down to 50.  That fixed it!  I called Bolton Ground to ask for a radio check and received a very welcome "Read you loud and clear" response.

With the two big problems fixed, there were just a few odd jobs to do to fill the rest of the day. One of the things that has been plaguing me for months is the monkey-trap nature of the canopy. If you were so careless as to get into the plane, lower the canopy and latch it, you were stuck in the plane until such time as someone could remove the handle from the outside to let you out. There was something maladjusted on the latching mechanism, obviously, but the fix was not nearly so obvious. The handle also had the annoying tendency to move positions when the canopy was closed - it would rotate enough that you couldn't open the canopy without having one hand holding the handle and the other lifting the canopy. And that is hard to do!

The way it's supposed to work is you're supposed to use a big pair of pliers to squeeze the tube that the handle goes down through, the idea being that the slightly squeezed tube will prevent the handle from rotating. The problem was that I either got the tube squeezed too tight or not tight enough. I wanted to try something else.

So, first thing first, Pete and I talked over the problem of the unlatchable latch. A number of possible solutions were bandied about, and we eventually agreed that we would attempt a fix on the lowest cost part of the assembly: the outside handle. The idea was to grind a little of it off in order to give the interior latch a little more room to clear the latching block. That worked quite well, so we moved on to the handle rotation problem. I had seen a suggestion for fixing this that involved simply putting a rubber O-ring in the assembly, so it was off to the hardware store to find an O-ring.

While we were there, I went ahead and picked up some number decals to put the tail number on the plane. I'm sure glad it's just temporary - it's really ugly.


The O-ring fit quite nicely and it keeps the handle from rotating. I was afraid the additional thickness would moot the effects of the handle-grinding fix, but what actually happens in practice is that the O-ring just rolls down onto the outer surface of the tube. When the canopy is opened, I just have to roll the O-ring back up the tube.  Piece of cake! I might investigate a more robust fix in the future, though.


Finally, we removed the plastic sheet from the canopy and riveted on the turtle deck skins.


All in all, it was a very productive day.

Thursday, September 20, 2012

One Step Forward, One Step Back

I only had a brief amount of time to fiddle with the airplane today, but it was long enough to run through the calibration of the autopilot servos. I was curious as to why they weren't showing up in the list of attachments attached to the Skyview, nor were the autopilot menu items on the screen. A quick foray through the foreign land that is Dynon documentation answered the question: you have to configure/calibrate the servos. Fair enough, and really not all that from calibrating a joystick on a PC game.

Once that was done, I figured out how to make it actually pretend to fly the airplane.

 

 I was surprised at how noisy it is - it will be hard to nap while it's clunking its way around the sky. Never content to rest on my laurels, I decided to try setting the volumes on the collection of noise makers, but soon found that the pilot-side microphone wasn't working. I tested the wires and they were good, so I threw in the towel and headed home. A little research on the internet leads me to believe that I might have a grounding problem. That will be easy enough to test, but if it doesn't help I am at a complete loss as to what I should try next.

Wednesday, September 19, 2012

It is.... ALIVE!

You've seen those movies. The protagonist has spent years of his life chasing a dream, shunned by society for his off-the-wall ideas and pursuits. His goal? Why, to create life, of course! Finally comes the big denouement: he flips a switch, or captures a bolt of lightening, or fills a syringe and injects a biological concoction. There is a pregnant pause... the camera zooms in on the creature's eyes.... AND THEY OPEN!

"IT     IS     ALIVE!!" he shouts!

And so it was that I installed a DB9 connector on the GPS antenna cable, plugged it into the J-box, and turned the page to see what the next step was.

There wasn't one.

I'm done with the avionics!

So, what to do? After pondering it a moment, I decided that I would hook up the main ground wire to the battery and see what happened.

Well, nothing happened. That was to be expected - I had ensured that all of the power switches were off.

The big moment would come when I flipped the master switch to ON.

5

4

3

2

1

SWITCH ON!!

Nothing happened.

Rats.

But wait, I think I heard the master relay thunk, so power was in fact coursing through the braided metallic veins of the airplane.  No sign of life on the Skyview, though. The eyes remained steadfastly shut. But... the Hollywood movie creature never displays sentience right away - there is always the suspense of apparent failure.

I did what I normally do when faced with one of Van's Little Mysteries: I fired off a questioning text to Kyle, saxophone reed custodian for The Jackson Two. He asked a pretty pertinent question in return: "Is it plugged in?"

"Well, of COURSE it's plugged.... oh, wait."

You see, there has been this pair of white wires with a black connector on the end that I have been pushing out of my way for days now, waiting for Van's to tell me to plug them in somewhere. I was pretty sure they went into the back of the center switch box, what with that connector being of the right shape and to date unfilled with anything at all. And sure enough, Kyle told me to look for a  pair of white wires with a black connector on the end.



I plugged them in and turned on the master switch again.

Fans started to whir.

And then......

The creature opened his eyes!


He began to speak, but I didn't understand a word.


The newly sentient creatures always ask two questions: "Where am I?" followed by "Who am I?"

The first question he already knew.


We're at Bolton Field, KTZR.


 The big red X means that the second question is still in doubt. Skyview knew where it was, but did not yet know who it was. A quick consultation of the installation guide told me that Skyview had to be told the tail number of the airplane before it would be completely cognizant of its identity.

And so it was...

Sunday, September 16, 2012

Tribulations

I had another occurrence of a Harbor Freight tool causing me some problems, but we'll get to that later. There are times when The Freight can be pretty irritating - just last week I dropped in to buy a handful of trifling stuff, only to find that (yet again!!) their POS (point-of-sale, but the other meaning too) system was locked up. Twelve Angry Men is more than just a Henry Fonda movie, if the visages of the impatient customers were any indication. I turned around and left.





Continuing on my stumbling path down the final stretch, I started out by changing a fuse. Bill H. had left me a note alerting me to the fact that the 2 amp fuse that I had put in the 'START' slot of my fuse panel might be insufficient and that a discussion with Van's had won him dispensation to replace it with a 3 amp fuse. While the plan page (for which there is no newer revision than what I have) stubbornly holds to the lesser of the two....


... the spare fuse block has seen the light.


I started out easy (or so I thought) with a couple of small-box installations. First was the Emergency Locator Transmitter (ELT) pilot-controlled ARM-ON switch. The primary means of turning on the ELT is to fly into something solid, but there are cases, such as surviving an off-airport landing way out in the boonies, where the pilot may need to manually turn on the device. The switch is normally set to the 'ARM' position.

The switch is held in place with irritatingly small nuts.


I'm not sure there is a small enough wrench or socket available for these nuts, but even if there is, I don't have one. I resorted to vise grips.


The ELT switch comes with labels and such that would show the correct positioning of the switch, but Van's tells us not to use them; they will be sending their own version eventually. The intercom gets installed under the ELT switch, but the ELT switch is small enough behind the panel for that to not be as big a hassle as it could have been.



The ELT itself rides back in the baggage area. It uses an internal antenna mounted to a little slab of aluminum. The plans show the ELT antenna mount being screwed into three open holes in the structural cross bar.


Imagine my surprise when I found those ostensibly open holes to not be open!


I went back and found the page where the rivets were originally put in - I was correct in putting them in. There may be a revision page out by now that has current/future builders leave those holes open. I kind of doubt it, though.

The holes will need nutplates behind them. A screw gets run through a nutplate backwards so the 'ears' of the nutplate can be used as a drilling template.


Getting those nutplates up into the cross bar was an exercise in finger dexterity, and served to remind me that I hate exercise of any variety!


The plans then call for the mounting of the ELT mount to the side of the plane. Perusing the contents of the big box that the ELT came in left me wondering "What mount??"


Oh, there it is! Already mounted to the ELT.


Cleco it in place - nothing to it!


Find these oddly shaped rivets. They're hidden in one of the brown paper bags.


I've never had an ELT that had a warning buzzer, but it's a pretty good idea. If you accidentally set off the ELT and don't know it, you'll be on the hook for a $175 replacement battery if you let it run for more than an hour. That, and you'll have the FAA and possibly the Coast Guard breathing furiously down your neck.

The buzzer needs a second ground wire and a pair of splices crimped onto it.


And here it is, neatly installed.


As I plugged in the little connector in the front of it, though, I nearly jumped out of my skin when the buzzer immediately started emitting a very loud and very strident series of beeps. The ELT was on!! How could that have happened? I turned it off just as quickly as I could (once they're on, they assume that you want them to stay on) find the sheet of "accidental activation" instructions included with the unit. That got it turned off, but did not answer the question of why it turned on in the first place. And the bulk of the instructions provided with the ELT were on CD-ROMs, which are utterly useless to me in the hangar.

I decided to shift gears until such time as I could go home and read them. It is only permissible to activate an ELT for testing purposes at the top of the hour (and even then, you only get a five minute window and the activation must be brief) so testing the problem would take awhile. When I got home, I scanned through the docs looking for a trouble shooting guide. One thing I noticed was that the drawings of the remote switch varied in which switch position was 'ON' and which was 'ARM', with 'ARM' being the position I wanted. And there I was, with no labels installed to help me tell the difference. Fortunately, I had pictures of someone else's panel that I could refer to. Sure enough, I had the switch set in the 'ON' position.

Duh.

But that all came later. I decided to finish the installation of the ADAHRS box, which is the box that does all of the air data calculations for the Skyview. As I was looking at the plans, I noticed that Van's doesn't like the DB-9 clam-style backshell for this particular connection, so I had to use an alternative style.


This style is slightly more complicated to put together the first, second, and third time you try one.




With that done, I went ahead and installed the ADAHRS box to the two supports provided (having been warned by Kyle, Work Avoidance Technician for The Jackson Two) before riveting them onto the airplane, and I am glad I did! It would have been a nightmare otherwise. By the time I riveted those brackets in, the ADAHRS had its pitot and static lines connected, and the DB-9 and the OAT plugs installed. The wiring back there will still need to be straightened out, but I was getting cramps from all of the contortions required when scrunching around in the baggage area.

I was just about done for the day, but I decided I'd install the GPS antenna. It looked easy enough.


It wasn't. I couldn't get it to align with the provided screw holes because the wire bundle was being obstructed by the hole in the mounting panel.


I filed a notch in the mount and was then able to screw the antenna to the mount, but when I went to install the mount onto the shelf on the firewall, I had the same problem.


I filed another slot, this time into the shelf. Unfortunately, I may have gone a little too Shogun when filing the edges to smooth them out. The Harbor Freight file broke.


There then ensued a prolonged search for the lost piece of file. The search, to date, has been futile and will have to continue before I can move on. Here's a lesson, though: when using Harbor Freight files, think 'Geisha', not 'Shogun'.

At least I was done enough to get the antenna mounted.



Saturday, September 15, 2012

Benefiting from Incompetence

Remember this?


No way that connector is going through that hole, but I had no idea at all how to remove Molex pins. While I (through necessity not always of my own making) eventually got to where I could remove the tiny, fragile gold pins from the DB-style connectors, I had no idea what to do about these, nor did I have a tool for doing so. What I did have, though, was the benefit of incompetence. I postulated that I might be able to move the little locking pins by pressing on them with a small screwdriver. That didn't work. I couldn't even see the locking pins. As a last ditch effort, I resorted to just pressing down into the middle of the pins with the screwdriver. Lo and behold, that worked! It worked because I had failed to full seat the pins in the connector in the first place!

Let's hear it for incompetence!!

With that out of the way, I was able to finish the addition of the matching connector to the wires remaining in the airplane and press on with the rest of the avionics work. That included the installation of the very first avionics box, which I have taken to referring to as the J-box:


The next step was to attach the front pitot tube to the aft pitot tube, the counter-intuitively subtractive math of which equates to 1 + 1 = 1. The problem was that the aft pitot tube was, well, still well aft. I had not yet pushed it back through all of the wire bundles it had been removed from in an attempt to make more room for wires in the bundles, as it were. This was one of those "pay me now or pay me later" deals I made with Van's, and 'later' was now. It was to be worse that Van's had intended; I had actually pulled the pitot tube further back than Van's had suggested, thinking at the time "Gee, that made this pretty easy. Why didn't they suggest this?"

Well, now I know. It was a miserable job to get that tube back up to the front, and the worst of is was that portion that I had done voluntarily.

It was eventually finished, of course, which is the nature of this kind of project. You do what you gotta do 'til it's done.

Moving on, it was to be a series of installing various Skyview modules that were previously built into the old D-180. As much extra work this has been, I am far happier to have the Skyview than the D-180, and these modules are one reason why. One of them breaks? Replace just the module, not the entire avionics suite. Some new capability comes out? Buy just the new module! Or don't - it's up to you. Much, much better this way.

The first to be installed was the Engine Management System, or EMS. This unit will accept various analog inputs from engine probes of various design and purpose, convert them to digital values, and pass them along to the main Skyview box for graphical display.


Next was a big backup battery that will keep all of the displays and modules working if there is a massive electrical failure on the airplane. That's a handy thing to have, right? It should have been easy as pie to install, what with it being only two screws and nuts.

The second screw didn't go well.


A second attempt at the second screw went even worse.


Even though I happened to have a copious number of spares available (these are the same type and size of screw that hold the spinner on the RV-6, so I have a bag of them handy at all times) it was getting tiresome. The problem appeared to be an excess of resistance from the lock nut. I thought a little lubrication might help.


It did.


Right next to that goes the USB plug that will be used to update the software that provides the smarts of the Skyview. For the D-180, this service was provided by a serial connector safely locked behind the cover of the tunnel. In other words, it was hard to get at. It made up for that by also being hard to use, requiring a serial-to-USB adapter to even get it attached to a laptop computer, itself not the easiest way to lug around update data. Now it is simply a matter of bringing a USB flash drive to the airport, one of which was even provided by Dynon!


Then it was fuses. Lot's of fuses.


Just in case a fuse blows, Van's even provides spares and a rack to keep them in.

Amazing!



The switch/fuse box is screwed into the center panel.


Which is then screwed into the supports. Van's had me countersink the panel in order to use flush mounted screws. I don't like them; I'll be using the old 'button top' screws for the other two panels. They better match the color of the panels.


With the center panel in place to support it, we were able to then install the tray for the comm radio. It was a pretty tricky job involving half a dozen very small screws and lock nuts, but once it was done the Garmin SL-40 radio slid easily into place.


The transponder, which in the D-180 world was a separate Garmin panel-mounted component, is now a module that mounts to the firewall. It rides in a mounting tray for easy removal, but I am unclear as to why I would want to be able to remove it. In any event, the tray ran into a little interference from a rivet that had been punched through the firewall from the other side.


I simply trimmed the tray a wee bit.


And the transponder itself never noticed.


The transponder antenna cable screwed in easily. The display and controls for the transponder are built into the Skyview display, so yet another data cable bundle runs over to the J-box to provide input to the Skyview display. There are so many of these loosely wrapped wire bundles that I started wrapping all of them in the plastic wire wrap I bought from Aircraft Spruce. This makes the bundles so much cleaner looking and it is so cheap that I can't understand why Van's doesn't ship some with the kit.


I ran out, though. I'll have to clean these up later.


Having tired of being clean, I decided to roll around on the floor for awhile. While I was down there, I installed the comm antenna. I thought that I would be kicking myself for not having installed the optional nutplates for the antenna base to screw into, but it was actually quite easy to do without them.


The transponder was even easier. Pete took his turn on the floor and pushed the base of the antenna up through the belly skin and I threw a nut on it. It took no time at all. Well, no time at all if you don't count the time that it took Pete to get up off of the floor. Maybe I should have done that part....


Finally, it was time to install the main Skyview screen. Piece of cake.



I went ahead and added the right side panel just for completeness.


Not a bad day's work, eh?