Saturday, August 23, 2014

Servo projects

No flying this Myday as my luck has finally run out in the realm of good weather - hot, muggy, and threatening thunderstorms in a most convincing tone. I took the opportunity to visit the new local indoor karting track, which was a ton of fun, but at $20 for an eight minute race (well, cheaper than that with a Groupon discount, but still...) it only took an hour - how to fill the rest of the day?

Easy: pull some projects off the shelf.  There's some back story to this, but I will try to keep it brief.

I all started with the airsickness detectors. These are little doors in the side of the airplane, one on each side, that are intended to allow a stream of cooling air into the cockpit which, if you think about it, it nothing more than a greenhouse in the warmer months. I call them 'airsickness detectors' due to the propensity of those passengers who are feeling a little queasy to "need more air."

In any event, once strapped in and settled into my seat, it is difficult to reach the control arm of the left side door and impossible to reach the right side. I started to think about a way to fix that to make it easier for a single person to adjust both doors. Having spent quite a few years of my youth building, flying, and crashing R/C airplanes, my thoughts immediately turned to servos, the little electric motors that move the control surfaces of the airplanes. The difference between a servo and a regular electric motor is one of proportional control - move the joystick in a specific direction, and the servo will track that movement proportionally. That means I would replace the joystick with a knob and use it to control the exact position of the door.

To do so requires some electronics. I spent quite a bit of time searching the internet for a way to create the electronic device required to do it, but eventually came across something better. This is exactly what I needed: the Dual Servo Driver from ServoCity.com. I'm going to go off subject here for a second to say something about ServoCity: buying stuff off of the internet is typically a impersonal affair, but something about the folks that run ServoCity makes it feel like you were right there in an actual store and waited on with a smile. Maybe it was the little packet of candy that they included with the shipment, or their very personable presence on Facebook, but either way it was a very satisfying experience.

So, with the servo driver on order it was just a matter of finding some servos. They aren't cheap, after all, and I wanted to be sure that this experiment would work before springing for them. Not a problem: I borrowed a few from The Jackson Two, who had also followed the tried & true path from R/C to real-world airplane building.

I got as far as building up a servo with a control arm that would fit well with the handle on the doors, buying a voltage regulator that would drop the 12VDC of the airplane power to the 5VDC demanded by both the servo controller and the servos themselves, and buying a pair of knob controls from China, and then....

I am going to digress for a moment here to introduce the technology that has emerged as the very pinnacle of the Selfie Generation's narcissism: the GoPro Action Camera. This tiny little device can be attached to just about any surface and provides crystal clear point-of-view video from all sorts and adventurous that most of us will never experience in person. Here are a couple of examples:






Things to note:

  - The camera(s) can be mounted to just about anything, but once mounted, the composition of the shot is fixed. This is true even in the karting video; the only reason that it isn't a fixed view is that the camera itself is mounted on a moving platform.
  - My life is unexciting - I feel like I could not live up to the standards of these GoPro users.

This changed my mind:



Having an airplane, I figure I can at least top that last one with no great (or risky) effort.

Although the in-flight portoins of this video were recorded with a competing brand to the GoPro, the concept is still similar:


Having mooted the second issue, I was left with the first issue to address: what to so about the fixed composition? It wasn't that big of an issue with the camera right there next to me in the airplane - if I wanted to bad enough, I could adjust the direction in which it was pointed. But what if the camera is mounted outside the cockpit?

Consider this video:



That required at least three cameras. They cost $400 each.  There has to be a better way to get more variety in the outside segments....

I think there is, and (not) surprisingly enough, it involves servos.

I got to thinking that only two servos are needed: one to pan the camera (rotate it left and right) and one to tilt the camera up and down. With two servos already in hand, I again turned to the internet for help and again found what I was looking for at Servo City, the SPT-100 Pan & Tilt System:


I would still need a servo controller, but rather than knobs I would want a joystick. Incredibly, Servo City had anticipated just that need with the Two Servo Joystick:


I ordered both products, along with a few smaller accessories. If you look at the pan & tilt, you see that the bottom servo serves as the base for the whole shebang. The next question was how to mount that to something solid.  Easy! Servo mounts.


Now it was just a matter of deciding where to mount it on the plane. I consulted with Kyle, Smoke Oil Manager/Technician for The Jackson Two Single-Ship Formation Team, who had previously mounted a GoPro to his plane. 

I decided that I wanted it to be on the bottom of the wing to allow for better viewing of the ground. This would be a problem for the camera operator, though, because he wouldn't be able to see where the camera was pointed (assuming a low-wing plane), but it turns out that a helper app can be installed on a smart phone and the app provides an electronic viewfinder. Perfect!

We decided on two potential mounting spots that would allow the mounting of the pan & tilt system to be installed without drilling holes into the airframe: we would mount it to one of the removable inspection plates under the airplane. I voted in favor of the one on the left wing just below and behind the leading edge, while Kyle favored one down in the belly of the plane. Both of us have expensive paint jobs on those panels that we were reluctant to mar, so Kyle came up with the idea of just buying new ones from Van's. They're dirt cheap, so why not??

With the not-so-great weather we're having this weekend, I finally got around to kludging together a rather sloppy mount. I used .063" thick aluminum to form a doubler to provide more rigidity and bolted the mount directly to that. The cardboard box is a simulated camera:


It only kinda-sorta works. There are a number of problems:

  - I got the orientation of the camera wrong, and it requires the complete disassembly of the mount to change it.
  - The servo attachments are too weak for this usage. There is a very real chance that they would work loose and drop the camera. It's not unheard of.



 - The mount itself if not rigid enough to hold the camera steady - this is also partially due to the servos hanging upside down. 

video

  - The mount sticks too far out into the slipstream. That could put a lot of pressure on the mounting plate. The .063" doubler is probably string enough, but it would be nice to have as little drag as possible.

This is the state of the project today, but after a little more research, I think I might have a fix for those problems. As it turns out, there is another mount that addresses pretty much all of my concerns: the SPT200 Pan & Tilt System, which mathematically speaking should be twice as capable as the SPT100. It's also twice as expensive, so there is that to consider.  It is designed for a heavier camera and has better rigidity, the servo mounts are far more robust, the center of the pan axis can be adjusted without taking apart the mount, and the bottom server can be installed inside the airplane.

Perfect!


I'm going to contact the folks at Servo City and see if they agree that this mount should be up to the task. If they agree, the next step will be to order one and give it a try.

UPDATE:

I received some feedback from others that have experimented with GoPro mounts - it seems that the protective plastic case of the GoPro is too flexible/not rigid enough. This allows the camera to vibrate, and its internal attempts to stabilize the picture cause what they call "jelly rolling."

This makes me wonder if I should be looking into a very rigid mounting system like this:


More specifically, in this configuration:


With the bottom of the servo inside the wing or fuselage, the aluminum mount plate and camera supports would provide a great deal of rigidity, but at the cost of the 'tilt' axis control and the protective box for the camera. I'm wondering if it is worth the trade-off. At a minimum, I think I would have to find a way to allow the tilt to be ground-adjustable.

An example this problem and ways of addressing it in a different modality of flight:





Saturday, August 16, 2014

Visiting Jim Soaghetti

We live in a time of not only constant and nearly immediate contact with friends, family, enemies, and work (but I repeat myself...), but also with a plethora of ways of doing so. Back in pre-Internet 1990, I had a view into the future when I took a job at Compuserve. This was my first exposure to virtual friends, online societies, and "internet-ish" chat rooms, but to compare the Compuserve social media offerings with what we (usually) enjoy now is to measure the contributions of Orville Wright's paternal grandfather to modern aviation. The seminal idea was there, but the vast and prolific modern day reality is so far beyond the first implementation that the ancestry is more honorary than anything.

Note that this always-on communication is almost ubiquitously in the form of text; there is relatively little face-to-face or voice interaction. As such, a premium is placed on the skill of typing quickly and accurately on the often smaller-than-you-would-like keyboard on a the screen of the immensely powerful computer (relative to even the most robust and sophisticated mainframe computer at Compuserve) that we casually carry in our pockets, purses, or pouches. Sure, we don't call them computers; in a nod to their heritage and vestigial telephonic capabilities, we call them smart phones.

If I'm completely honest, though, the premium is really just on typing quickly - no one really gives a fig about accuracy. This accounts for the introduction of faux-typing technologies such as Swype. There is no good textual way to describe Swype to those who have never experienced it, so I will defer to YouTube (which I have taken to treating as 'Wikipedia for Dummies' in a hopefully non-offensive way):

  

As is not uncommon with modern "efficiencies," Swype is not without its own collection of irritations and frustrations, the chief of which is the ease with which typos (Swype-oes?) and misspellings can occur. Combined with the ambiguities introduced with sloppy Swyping and the incumbent often amusing misunderstandings delivered by a confused spell checker, some level of miscommunication is bound to occur.

So, short story long, I received the following cryptic message from Kyle, Assistant Marketing Communications Manager for The Jackson Two:
KHTS has a car. Jim's Soaghetti house is close.
Hmmm.I was able to decode the first sentence pretty quickly, correctly assuming the KHTS was an airport, and that said airport (wherever it is) has a courtesy car for transient pilots to borrow. The second sentence caused me pause, for I know of no mutual acquaintance named Soaghetti. My first thought was that the message had been misdirected and was actually intended for someone else. This happens quite commonly, and it can sometimes be awkward, such as the time I intended to send "You mom is getting tanked on Margaritas" to Co-pilot Egg, only to hear Mom's cell phone signal an incoming text moments after I had hit 'Send.'

Further deliberation of the nature of the possessive ruled that out; it said Jim's, not Soaghetti's.

It took about a minute for the non-incandescent government-approved CFL or LED light to go on: it must be Jim's Spaghetti House. I had never heard of that either, but it seemed reasonable that such a place could exist. But to fly all the way to West Virginia (KHTS turned out to be the airport identifier for Huntington, WV) for spaghetti?

Well, another weakness inherent in textual communications is the lack of tone. It is that fault in the technology that masked the shocked sarcasm in my reply:
You want to go to Huntington for spaghetti?
What happened next is entirely my fault. Had I instead said "You want to go all the way to Huntington just for spaghetti???" it may all have turned out differently. Or not. We will never know. As it was, the reply was equivocal:
Sure.
Eh, why not. It's Myday Flyday, right? Never having been to Huntington, I figured it would be an interesting trip.

Kyle's airport is just about exactly on the straight line path from my airport to KHTS, so he suggested that I stop in there. That way we could share the flight further south to Huntington rather than have both of us fly our own planes as we usually do.

I have finally figured out where Steely E. Toad resides when I'm not there - he squeezes down under the door. I will note that his ability to do so is why he's still alive. Have you ever heard that thing about a frog not jumping out of slowly heating water and getting boiled as a result? I don't know if is true or not, but I do know that Steely will not hop out of the way as the door descends. I brought it down a couple of weeks ago without noticing where he was and was mortified to see him "crushed" under it when I emerged from the man door.  No harm done, though.


This flight would also serve as a test for a few new pieces of airplane kit. First and foremost, this flight would determine if I was in big trouble with regards to headsets. You see, while I was up at Oshkosh, my normal parsimonious tendencies were overcome by the desire for a pair of active noise reduction headsets. Standing in line on Wednesday at one of the vendors to buy replacement ear seals for the pair of 18 year old Dave Clark headsets that Co-pilot Egg wears, I found myself pontificating in her general direction about by innate inability to spend $600+ on a pair of headsets, which caused the guy in front of me (who was getting ready to buy a $1,000 headset) to turn around and give me a disdainful glare.

By Thursday afternoon I was the proud new owner of a $637 pair of Dave Clark Pro-X headsets.  While they served as a somewhat extravagant birthday present, I am safe in the knowledge that they will last for decades. After all, my newest pair of DC's is eighteen years old and still working fine, albeit as a reduced comfort level from the worn out ear seals.

Unfortunately, the moment I plugged them into the airplane and turned out the power, an insanely loud feedback squeal screamed from the old pair of headsets on the passenger side. This let to a fairly high degree of angst that was only somewhat abated by learning that this is a known weakness in the intercom selected and configured by Van's. The upshot is that you can't have monaural headsets paired with stereo headsets.

Rats.

The last thing I wanted to do was forgo the improved hearing protection of the new headsets.

The second to last thing I wanted to do was add additional cost to the already large financial outlay just to fix a short-sighted wiring decision on the part of Van's.

I'm no King Soloman - I went ahead and split the baby. I sold both of my old monaural headsets to a Van's forum member (he got a great deal because he's an RV guy) and bought a low cost set of stereo headsets for the passenger. Because I usually like my passengers, I also bought the $17 optional gel ear seals.  I turned a small profit on the deal, so there is that.

The results of the test? Spectacular! Not only is there no squeal on the radio or intercom, I can also now hear the gal that lives in my Skyiew when she tells my important (and unimportant, but I think that's configurable) stuff. I thought there was something wrong in the wiring that made her next to impossible to hear, but now I realize it was just another symptom of the stereo vs. monaural problem.

And get this: I can also pair the headsets to an iPod and listen to music as I fly!

Mixed blessing, that. I couldn't help cringing when I was on short final to land at Jackson when a foreboding piece of movie soundtrack music started pumping into my ears.

I was also testing a sun screen. The canopy of an RV can often transform the cockpit into an unholy mix of sauna, tanning booth, and radiation oven. There is a very nice retractable shade available, but it costs an unreasonable $165.  Instead, I grabbed a $3.57 automotive screen at Wally's Mart.


Finally, this would be my final test of the Garmin Virb video camera that I had borrowed to see if it would be a suitable lower-cost substitute for the more common GoPro camera.  The difference in price between the to is a little over $100, so given the chance to borrow one for a field test, I took it.

The possibility of my scaring up $400 for a GoPro is still remote, but I can say with certainty that I won't be buying a Virb.  I hated it. The screen interface is clunky and its behavior is seemingly random when trying to navigate to any specific screen/function, but I suppose I could live with that - I would eventually learn it. No, the big disqualifier for me is the unreliability of what should be one of its strongest differentiators. In their marketing, Garmin makes a big deal out of the large, meaty, easy-to-operate 'record' switch on the side. The idea is that you can simply switch the recording mode on and off by using just that switch, which is a huge boon to people wearing gloves or folks distracted by the need to fly the airplane.  Unfortunately, it doesn't work reliably. While the indicator indicates that the camera is recording, when you get back home you find that it was working only half the time.  That makes it essentially useless.

Here are a few clips of it actually responding to my command request to record.  First, a unique perspective on the routine roll-out from the hangar:



What's most unique about this video is the way that it so startlingly reveals how little I have to contribute to the vast collection of very interested GoPro-esque videos.

Only slightly more interesting is the video of the takeoff, which was followed by a cruise departure at 95 knots and 500+ foot per minute climb rate. Oh, and if you stay until the end there are a few steep banks just for fun.



One of the clips that failed to record was the approach and landing at Jackson. That's a shame - you would have been able to see an airport worker casually strolling across the end of the runway just before I came swooping in low in order to land as close to the end of the runway as possible. I wanted to make the turnoff for the first taxiway since the ones further down the runway are closed for maintenance. It ended well, or so I can safely state since there is no video evidence to testify otherwise.

Flying-wise, it was a normal morning, by which I mean there was some ground haze. Looking straight down, though, it wasn't too bad. This is Circleville Raceway Park, our local kart track. I raced there for three years back in the 90's and would like to do so again, but I just don't have the time for it.


Morning flights down south come with the risk of low-lying clouds, or fog, depending on precisely how low the clouds are lying. It wasn't bad at all.


Upon landing at Jackson Co. and leaving the plane sitting in the sun for a few minutes, I found that my sun screen was every bit as disappointing as the Virb. I'm starting to think that "you get what you pay for" might be applicable to both of these things. The little suction cups are not up to the task of staying stuck when they get hot. Ironically, I have this exact same problem with the Garmin GPS in my car, but look at that! The Garmin Virb is still holding tight.

Know why? Because it's a GoPro suction cup mount, not a Garmin mount. The Virb (cleverly) ships with a GoPro mount adapter.


With Kyle's plane out of the way, I availed myself of his capacious hangar space.


They just have a different way of doing things at airports that have self-service pumps. You can bring the gas to the plane, rather than having to wait for a fuel truck or take the airplane to the pumps.


See how relaxed Capt. Kyle is? That comes from $637 headsets and a $165 sun screen. What price comfort? Easy: $802.  Plus tax and shipping, if you don't buy the stuff at Oshkosh.

I'm 79.426% there, so maybe....


This is either Lake Jackson or Jackson Lake, but either way it reminded me that I need to do something about getting some bars welded onto my canoe trailer so I can use it to carry my kayak. That looks like a great little lake for Yakking!


Again we cross the Ohio River. It is becoming routine.


Huntington has a HUGE runway!  Allegiant Airlines flies in and out of there in Boeing 737s, so it gets used appropriately. I'm going to look into Allegiant - they also fly in and out of Rickenbacker airport, which is only a few minutes from my house and doesn't have the same level of TSA hassle as Port Columbus. And due to their business model, a one way ticket to Tampa Bay is only $83.

Now that's tempting!


We parked next to another experimental. This is a Glasair, noted for both their beauty and efficiency. They are, however, constructed primarily from fiberglass, which is probably my least favorite material to work with.


The Crew Car came with far more rules and formality than is usual, but we weren't exactly out in the boonies, either.


Small cities on the banks of the river often have more than the average amount of older architecture.


As far as courtesy cars go, it was a fairly decent, if not anonymous, car.


That building in the background would have been considered huge back when it was originally built


Ah, here's Jim Soaghetti's house, family owned and operated since 1938.  The official name is Jim's Steak and Spaghetti (leaving open the question of where 'House' comes into play), so naturally to my contrarian nature, I had fish.


Oh, there's the House:


We sat at the counter diner-style, as is my wont.


Maybe because it was Friday, or maybe because it's really, really good, but they were moving a lot of haddock:


I know I liked it!  Tender and flaky inside their homemade breading. Yum!



Vestiges of past usage. But... European Plan?  Does that mean common use, shared bathrooms, or that you have to put coins in the room heaters?


As is becoming part of our travel agenda, we went antiquing.  I liked the idea of owning this, but I was not as excited about the $125 price tag.


Kyle, by far the more strategic shopper, developed a friendly relationship with the owner...


... which resulted in getting a very clean example of an old fire extinguisher for only $75. He didn't actually have $75, but he took it home with just the promise of sending a check later.

Small towns are so cool!


Meanwhile, I found a 70 pound bronze giraffe that Co-pilot Egg would have just loved!  I, having not invested my time as wisely as Kyle, was presented with a $950 asking price.

Nope.


On the other hand, Egg has started a collection of shot glasses. There was an unmarked antique "cheater" shot glass (A "cheater shot" glass simply has a thicker base which fools people into believing that there is more alcohol in it than what is actually being consumedthat I thought I'd get for her if it wasn't too dear. I held it up to the shop owner for a price.


"What's the most you would pay for that?" he asked.

"No more than ten bucks," I replied.

"Oh, I was thinking more like two or three bucks."

"Well, since I offered ten, I'll give you three," was my counteroffer.

He said, "Well, you're a good team player, but I only want two."

Sold.

Another thing to do is walking around in old hotels, something I took an interest in years ago when I went to French Lick, IN.













Climbing back out on our way back north, we were again treated to a view of the vibrant commerce plying the waters of the Ohio.



Capt. Kyle made use of the geo-synchronized approach plates in the Skyview to find the airport.


I jumped in Delta Golf to continue the trip north.


And finally, home sweet home airport.