Showing posts with label Finishing; Engine Run. Show all posts
Showing posts with label Finishing; Engine Run. Show all posts

Monday, November 5, 2012

Getting back to work


I'm sure you've been wondering... 

Why haven't I been posting updates on my progress? Because there really hasn't been much. There are a number of reasons for that.

The weather has, of course, been miserable, and so have I. Regarding the weather, I really shouldn't complain. Yes, it's been cold and windy, and it's getting dark ever-so-early these days. Yes, I am frustrated that young Cabot Bennett, of whom I do not expect a tremendous amount of intellectual acumen, remains convinced that I can summon forth light and heat at will (and to be fair, from his inside-the-house perspective, I can!) so that we can go outside and play but simply choose not to.  He is immutable in his belief that if he stares at me with big, sad, plaintive eyes long enough, I will exercise my god-like light-creating gifts and we can go outside for some fetch.  Yes, these are weather-ish frustrations, but they are nothing compared to what's happening out east.

But still, they are my frustrations. So, they matter.

Nor did it help that I somehow ended up with godawful muscle spasms in my neck and shoulder.  Bad, they were, and not conducive to any productive activities (such as throwing a ball for the dog). They were far more conducive, as it turns out, to sleepless nights and an extremely edgy mood. ("Go AWAY, Cabot!!")

This continued well into the work week.  I finally broke down and made an appointment with my chiropractor. I have to say, I think I really impressed him this time. He poked and prodded around the neck/shoulder area for longer than usual, and finally proclaimed his diagnosis:

"Oh, my!"

Yeah, tell me about it! He did what he does to get the bones back into their proper places ("Two vertebrae and a couple of ribs - what did you DO??") and started trying to work the knots out of the spasming muscles. He found one particularly bad spot (I can how badly the muscle is clenched  by how much it hurts when he presses on a spot , and this one hurt a lot!) that he started working on. 

"It feels like you swallowed a golf ball!"

I should be so lucky. Ipecac is dirt cheap compared to this guy.

After a better night's sleep and a dose of muscle relaxant, I was pretty much, almost, more or less, maybe, back to my normal contumacious and surly self.  For awhile. Things are pretty weird at the office, though, and I'm in one of those phases where everything I touch turns to, well, something worse than when I started.

A couple of days ago I was frazzled from a morning of enduring the irritating shriek of those blasted motorized weed blowers that had been running outside my window all morning, I tried to escape for a little peace and quiet at a nearby Chinese restaurant, only to get to my pretty little car waiting for me in the parking lot and see its grill stuffed with hundreds of leaves blown there by the Professional Leaf Blowing Squad from South of the Border.

Grrr!

I got to the restaurant and settled into a booth. I was just getting started on reading my book (more on that later) when what do I hear? Yep, another trio of motorized leaf blowers working their way down the sidewalk outside the restaurant. Just as they reached the door, another pair of customers opened it to come inside. So in addition to now having to endure the unadulterated screaming of those cursed things, I also got to enjoy the cloud of noxious fumes that blew in with the recent arrivals. Who, as it turns out, sat down at a table right next to me and started to have a heated argument about the pros and cons of using the default record ID versus creating a proprietary new one.

In other words, geek talk.

Not just that, but heated geek talk.

“I would most wholeheartedly argue against that approach!” one of them said in what passes for vehemently in geek circles.

It was like overhearing a pair of ninety year old English butlers arguing over the merits of two-minute versus three-minute basted (“No, my illustrious friend, I will fight to the veritable death to prove that anything cooked longer than two minutes is poached!”) eggs.

As to the book. It is the story (told in first person) of a woman who has a friend who is having an affair and shares the secret with her. This causes her to reflect on her own comfortable yet unexciting marriage to (wait for it….) an IT geek. 

Hey, it was free.  You get what you pay for on Amazon. And it's supposed to be a murder mystery, but the only thing dying so far is my interest.

Anyway, she decides to “re-sexualize” their marriage, but continues to run into difficulties along the way, thus making her more and more frustrated. The husband has to work late and comes home too tired. He goes golfing in the morning and comes home in the afternoon, having invited another couple over for dinner. This naturally stymies her Saturday night plans for which she had gone to the pain of buying some nice, uh, intimate clothing at Victoria’s Secret. 

And somehow this is all his fault!! 

This bothers me no end. This is the biggest problem men have with women. Listen, we’re not fricking mind readers. We don’t have brain scan modules implanted in our frontal lobes moments after circumcision. If you want us to know something, TELL US!!! Especially if it's uh, you know, that kind of thing. Trust me, we're all ears when it comes to THAT!

And then…. A new arrival came through the door (quietly this time) and plopped down in the booth behind me, where he commenced to have a profanity-laced cell phone conversation. It finally wrapped up just as I was surrendering the game and getting ready to leave, figuring my office would be more relaxing than this had turned out to have been.

“Yeah, dude, we just gotta keep on keepin’ on.”
I wanted to shove my fortune cookie down his throat.

I did manage to get a couple of things knocked off of the RV-12 to-do list, though. First and foremost, the airplane moved under its own power for the first time!  I finally was able to re-do the engine run that I had to abort the last time I tried due to the loose valve covers. It was a little chillier this time around so I had a good ten minutes of sitting at idle waiting for the oil temperature to reach the requisite 122 degrees. While I was waiting, I spent a little time messing around in the Dynon SkyView EMS setup pages trying to get the fuel pressure gauge to work. The sensor mapping page showed the 'Kavlico 0-15 psi sensor' as having been detected and functional, but it was displayed in a bright red font. That font selection could only mean one thing: "SOMETHING IS WRONG!"  I noticed that the sensor didn't have a setting in the column next to it that displays what the SkyView thinks it should be doing with this sensor. I played around with the menus until it said 'PRESSURE', or something like that. I'll have to go back and get a picture of it. The net result was that the fuel pressure started indicating on the Dynon screen. Score a point for my side!!

The right side CHT was still showing a big red FAIL X, so it wasn't a complete victory.

The oil finally reached a decent operating temperature and Pete was not gesticulating wildly about anything amiss in the realm of leaking fluids, so I ran up the engine to wide open throttle. The RPM topped out at 4,750 rpm, so the prop angles will need to be adjusted to find an additional 200 RPM.  The good news here is that the brakes held the airplane at bay even at full grunt. That gets a checkmark on the acceptance test sheet. Figuring I had the motor warmed up and proven useful brakes, I had Pete pull the chocks so I could taxi around a little bit. It drives like a dream!

After the engine was shut down, I pulled the panel off of the avionics bay. Pete and I teamed up to test the continuity of the BLUE/PURPLE wire that runs from the CHT-R thermocouple post on the engine up to the Van's J-Box in the bay. Dead as Kodak's business model. Or so I thought. Pete took a look and pointed out that I was testing the wrong wire. I was testing the BLUE/PURPLE wire that comes out of the J-Box and plugs into the Dynon EMS module hanging on the firewall. As he pointed out, we really didn't know for sure if that was the correct wire. Just being the same color code should be enough to know, but given Van's demonstrated proclivity for practical jokes, it wasn't.  I removed the connector that provides the input to the J-Box and tested the wire there.

It was good.

Damn. That means the problem lies somewhere out of my purview.  It's either a Rotax, Dynon, or Vans problem, and of those three, Dynon is simultaneously the least likely to be the culprit and most likely to be helpful in troubleshooting. I decided to start with Vans.

As I sat on hold waiting for someone to answer, I couldn't help thinking "I hope it's not Ken. I hope it's not Ken." I'm still a little bitter after having to argue over whether or not they had sent me a $.75 adaptor plate. I said they hadn't, he said they had because "they made a pretty good guess as to who would need one."  He said that I probably had just lost it. Now, we all now that it is more then possible for me to lose something; history is on his side there. But here's the thing: I know when I've lost something. I remember actually having  had it, I just don't know where it is.

So, a few minutes later my call was answered. I explained the problem, I explained what I had already done to troubleshoot the problem, and I ended with, "I don't know what to do next."

"Neither do I," was the response.

Sigh.

Ken.

After a brief pause to swallow my first response, I said, "Well, why don't we try to figure it out together."

That worked. From that point on it was a professional and moderately helpful call. He suggested testing the continuity through the J-Box and up to the Dynon EMS module. To do so, he said, I should consult the wiring diagram on the Van's website.

Fair enough, but I couldn't help thinking that I already did that. Sort of, anyway.

So I pulled up the wiring diagram. I traced the BLUE/PURPLE wire up to the J-Box on the diagram. It was right next to the YELLOW/PURPLE wire that comes from the left side.  Coming out of the J-Box, the right side CHT is YELLOW/PURPLE, and the left side is BLUE/PURPLE.

Pete was right.

Again.

And so was I, in a way: another practical joke! What other explanation can there be for transposing those two wire colors??!

Hopefully I will be able to get out to the hangar while the good weather holds to check the rest of the continuity path. The goal at this point remains the same: figure out which of the four players owns this problem.



Wednesday, October 24, 2012

The First Start

You can tell when an airplane project is almost done when you start to get visitors that want to sit in it and pretend to be flying. To be fair, I asked Co-pilot Egg to try it on for size.  She got a real kick out of the video-game style avionics.



Before too long, she was trying to bridge her knowledge of what old-style mechanical gauges looked like to what the new fancy-schmancy stuff built into the Dynon. Unfortunately her experience with the antique stuff never prepared her for an electronic HSI, synthetic vision, or terrain avoidance.


With the tourism obligation fulfilled, I turned my attention to the first time starting the engine. This is not as trivial as one might assume. The Rotax is very different from the traditional airplane engines that I cut my teeth on lo those many years ago, and continue to use today. A couple of major differences are the dry-sump engine oil system and the fact that the sides of the cylinders are liquid cooled. Both of these differences manifest themselves quite heavily when it comes time to introduce the applicable fluids to the engine. This became difficult almost immediately - I spent quite a bit of time trying to deduce the correct flavors of antifreeze and motor oil. I ended up with a 50-50 pre-diluted DexCool antifreeze (Prestone, I think, but the actual brand name matters not) and Mobil 1 V-Tail synthetic motorcycle oil. Motorcycle oil is used because it contains the additives required to keep the gear box happy.

Having the proper fluids on hand is important, but it is equally important to know how to introduce them to the engine. There are procedures spelled out in Rotax Service Instructions (which you're more or less required to go find for yourself), but they are somewhat reticent in nature. They aren't completely useless, but they certainly spare words whenever and wherever they can. Best, I thought, to have The Jackson Two lend a hand given that they have relatively recent experience with the process.  Now the thing to know about these guys is that they don't just come up from Jackson and consult from the sidelines; it really ends up being something more akin to an Amish barn raising. They jump right in and we get some really efficient teamwork going almost immediately. This is, of course, one of the chief selling points of the Van's RV airplanes - the spirit of camaraderie and the willingness to share knowledge simply isn't available in any other community.

So, here's the antifreeze going in. It actually gets poured into two locations: the little reservoir on top of the engine and the additional reserve in the little plastic jug hanging on the firewall.



The oil purging process is where the real complexity lies. You don't just pour the oil in like you would with a dry sump Lycoming. Rather, you have to put air pressure on the system to assist in getting the oil pushed completely through the much longer path of hoses and coolers that are the hallmark of the Rotax dry sump engine.  To get the air pressure behind the oil, the oil return line is removed from the oil tank and the fitting gets plugged. The overflow line is removed and the air source is plugged in at the fitting. A regulator is used on the air hose from the compressor to keep the PSI below a meager 15 psi. The maximum allowed is 15 psi, but we used something more like 5 - 7 psi.


Naturally I was in charge of making sure all of the required parts were on hand, which is why we didn't have a cap for the oil tank. I ended up taking the "parts on hand" responsibility quite literally as a result.


While I held the air pressure in with a finger, Kyle swung the prop. Pete monitored the engine monitor. The idea was that somewhere between 20 and 60 swings of the prop, Pete would see an oil pressure indication on the Dynon.


Quite a few prop rotations later, success!


And there we were: the moment of truth!


We spent the last few moments going over the start procedure (throttle to idle, choke on, ignition switches on, crank the engine, choke off when it catches, throttle to 2,000 rpm for two minutes, throttle up to 2,200 - 2,500 rpm until the oil temp reaches 122 F degrees) before I locked myself in for the big moment.



And there it goes!!



Kyle hunted for leaks or other untoward events while I puzzled over the big red FAIL X sitting over the indication for the right side cylinder head temp. 

Great, a wiring problem. Ugh.



After the required oil temp was reached, I shut it down and pushed her back into the hangar to the next step.


The idea is that the engine would have run long enough to fill the valve lifters with oil. This needed to be checked, though, because a "soft" lifter is going to be a problem when the engine is run at higher power settings.


It only takes the removal of a single allen head bolt to get the covers off. Then it's just a matter of pushing on the valve springs to test their resistance.


The piston for each cylinder has to be at the top of its travel to make the test work correctly.  That means looking down into the sparkplug hole looking for the top surface of the piston.


With all that done, I went for extra points. I don't have a big cut-off wheel, so I had them bring theirs. I wanted to take an inch off of the exhaust pipe because it's too long and interferes with the installation and removal of the bottom cowling.


In case you're wondering about the marked improvement in the quality of the pictures, most of them were taken by Pete's son Keith. I should have hired him on as staff photographer ages ago!