Saturday, August 9, 2008
Giving Credit Where Due
That in this Business we are all to Learne
and none to Teach...
-Robert Cushman, 1619
The Chugger Project is an on-going series of experiments using
inexpensive, commonly available materials to build a simple
single-place airplane. As the work progresses, drawings and photos
are placed in the Files archive of the 'chuggers' Group on Yahoo.
Text and periodic progress reports are posted to my blog.
It's important to note that the primary purpose of these experiments
has to do with materials and methods. For the structure I've simply
scaled up (or down) from proven designs. In doing so, I've tried to
give credit where due, although that isn't as easy as you might think.
Bernard Pietenpol used parallel wing struts on his Aircamper ...but
so did Claude Ryan on the NYP. The scaling is necessary because the
inexpensive, commonly available materials I'm using do not enjoy the
same ratio of strength-to-weight as for aviation-grade materials.
Pete Bowers' Fly Baby has a beautiful empennage. By adapting Pete's
empennage for the 'chugger' project, I'm paying homage to a past
master but in doing so I'm taking advantage of an invaluable
training-aid. Pete's tail-feathers incorporate no less than nine
built-up spars of box- and C-section designs, as well as curved
laminations. For the novice builder, the empennage is their Trade
School. Fabricating the tail-feathers provides a No-Fault opportunity
to acquire the skills they will need to build the wings and fuselage.
Clearly, the Fly Baby's empennage is more complex than the relatively
simple structures found on a Volksplane or Jo-Del but when scaled for
the Chugger , none of the components are especially large, reducing
these training materials to table-top dimensions. If fabricated from
locally available materials such as door skins and Box Store lumber,
the cost of this training exercise is only a few dollars. In fact, if
the goal of the novice is merely to learn how to build a wooden
airplane, there is no reason to build the entire tail, making the cost
even less.
While the parts-count of the Fly Baby tail makes the structure fairly
complex the required skill-level is delightfully low. Most of the
parts are duplicates, allowing you to take advantage of stack-sawing.
For example, the six shear-webs needed to produce the spars for the
elevators and horizontal stabilizer may be cut-out at one go. The
same holds true with the four shear-webs needed to produce the
stern-post and rudder spar. The diagonals in the horizontal
stabilizer are identical, left to right, so they too may be cut-out as
a stack. The only singleton is the shear-web for the diagonal brace
in the vertical stabilizer. That means all thirteen shear-webs can be
produced from only four patterns.
Once the shear-webs have been stack-sawn, Pete recommended attaching
the spar-caps and filler-blocks to them. In effect, the shear-webs
become your patterns. Since you're dealing with straight edges here
you need only apply a bit of glue (to both surfaces, please), tack a
piece of scrap to your bench-top to act as a back-stop, press the
pieces firmly against the bench (don't forget the waxed paper) and
tack them together with a pneumatic pin-nailer. Thanks to the use of
the pin-nailer the work took only a couple of hours Then comes
fitting the filler blocks, which takes longer – a couple of months
longer in my case, thanks to some health problems that had me lolling
around various doctor's offices instead of working in the shop.
In October 2007 I received a comment from Mr. Corrie Bergeron who is
building a Fly Baby. Corrie pointed out that there were other,
equally accurate methods of fabricating the empennage spars and
diagonals than the one advocated by Mr. Bowers. Rather than make the
shear-webs first – and use them as patterns – Corrie fabricated the
guts of the spars first – and used the guts as the pattern for the
shear-webs. Since I'd already tackled the project using Pete's method
I attached Corrie's comments to the appropriate article in my blog
http://bobhooversblog.blogspot.com/2007/09/av-chuggers-tail.html
Once back on my feet I was anxious to finish the tail surfaces, hoping
to carry the job right through to covering. But before doing so I
recalled the words of Robert Cushman and thought it only fair to give
Corrie's method a try, allowing readers of the blog to draw their own
conclusions. Accordingly, I made up a simple jig for the spars of the
elevators and horizontal stabilizer.
This may verge on heresy but I found Corrie's method offers several
advantages for a novice builder – or for any builder without a shop
full of tools. Pete's method of stack-sawing is dead-simple and
superbly accurate... if you happen to have a band-saw and a big belt
sander. But for the boxed spars, after attaching the spar-caps and
filler blocks in the recommended manner you're faced with the chore of
figuring out where not to varnish on the other shear-web. Corrie's
method offers greater latitude for the novice builder.
I've not posted any photos of the two methods as yet; I'm trying to
learn how to embed video in the blog. When I do, it may appear that
I'm changing horses in mid-stream when in fact I'm merely showing that
even an old dog is capable of learning a new trick – and of giving
credit where due.
-R.S.Hoover
PS – Robert Cushman was one of the Pilgrims
NOTE: This article was originally uploaded to the Fly Baby Group about two weeks before I was diagnosed with cancer.
Thursday, August 7, 2008
How ya' doing?
“How ya' doing?” tumbles out of my in-box a dozen times a day. Surprisingly, most of the queries are from people I've never met. When they provide a valid e-mail address I tell them I'm doing fine and thank them for asking but most aren't meant to be a medical report; most are a simple show of solidarity from one airman to another. And as I've said to them, it is warmly appreciated.
As for the purely medical aspects of 'How ya' doing?' I've completed the radiation therapy phase and have started on chemotherapy. The pain is pretty much under control, my weight-loss appears to be flattening out and I'm getting more sleep. Overall, I think you can say I'm one lucky fellow.
Some say we make our own luck. I've got good evidence that much of it is a shared commodity, transferred from one individual to another by something as simple as asking: 'How ya' doing?'
Just fine, thanks. But a lot of that is because of you.
-R.S.Hoover
Wednesday, August 6, 2008
Cancer Report 01
On Tuesday, the 5th of August 2008, I completed the radiation therapy. The x-rays have supposedly chopped up the tumor, killing most of it. In doing so, the PAIN has been reduced to a magnitude that is relatively easy to manage. And it's really all about controlling the pain.
After being destroyed by the x-rays the tumor doesn't just vanish. Apparently it is blasted into a soupy residue that your body must now eliminate. I'm told this will take about four weeks and will be the most debilitating phase of my treatment, in that I will be extremely weak. There is already some evidence of this. Even with two canes to ensure my stability, walking about forty feet left me too exhausted to return until I'd taken a rest break.
To facilitate the removal of the tumor residue I must force myself to drink about twice the normal amount of fluids. Doing so also serves to dilute any pain-killers you may have taken so that you are forced to keep track of what you've taken and when. Failure to do so gives the pain an opportunity to sneak up on you. If it gets you at the wrong time, you may find yourself immobilized, separated from your pills.
Chemotherapy is the hand-maiden of radiation therapy. Where the x-rays attacked the tumor in a macro fashion, chemotherapy goes after the cancerous cells in a micro-manner, seeking out each individual cell, which it either destroys of prevents from binding to a healthy cell and reproducing. The chemicals used to attack the tumor are toxic and there are a number of side-effects, such as nausea, hair loss and so forth. The chemotherapy began about two weeks ago and will continue for several months at a minimum.
Multiple myeloma destroys bone. Once destroyed, it can not be replaced except through surgery, which is successful in only a few particular cases. The damaged bone is quite fragile. There is the possibility that performing some accustomed chore such as dressing or bathing can over-stress the weakened bone causing it to fracture. There are chemicals that can bind to the damaged bone and provide some re-enforcement and I will begin taking those chemicals as soon as blood tests say the bone is ready to accept them.
So the messages ask: "How are you doing?" And I respond: "Fine; thanks for asking." But as you can see, there's a bit more to it than that. Such as the rash, a nasty side-effect of the chemo. Or the edema in my lower legs, an artifact of the tumor residues. And a dozen other little things that taken on the whole make it impossible to offer a comprehensive answer as to my condition.
Which is why I'd rather look at it from a slightly different perspective.
I'm a pretty lucky guy. I came within an ace of dying from an unsuspected tumor, recognized -- and properly treated by a superbly skilled physician who just happened to be in the ER when I was brought in. I'm doubly lucky in finding myself surrounded by people -- many whom I've never met -- who have provided support and encouragement that has served to level the often difficult path I have been forced to follow.
-R.S.Hoover
Saturday, July 19, 2008
The Orphaned Engine
Unfortunately, the offered example invariably deals with cars or trucks, things in which the fellow has a life-time of experience, whereas automotive in the sense used here, does not, although it could include them. To an engineer, automotive means something that can move under its own power. Like an oil tanker, the Space Shuttle, or a gold dredger.
My usual reaction is to hit the delete key. I get more mail than I want, most from people with real problem, some of whom I can help. But it's always sad to hear smart people say dumb things. And on the whole, these are smart people, even though a life-time of experience hasn't tipped him off that we're taking about two different meanings for automotive.
We all start out pretty dumb. As we age we gather information and gain experience and, assuming a fair share of native wit, we end up a bit smarter than when we began. Mebbe all this guy needs is a nudge in the right direction. So you say hello and the odds are the fellow is having the same problems as everyone else except he was a bit too proud to say so.
With this type of Expert you'll often discover his life-time of experience has been with just one type of engine or perhaps one type of car and he has been trying to transfer that experience to a Corvair or a Volkswagen and isn't having much luck. I mean, who ever heard of a head torqued to only eighteen foot-pounds! That has to be wrong... right?
If the fellow hasn't figured out the meaning of automotive there's a good chance he won't have any idea in the blue-eyed world about Class of Service but a good understanding here is the real key to a successful conversion so you give it a shot.
A car or light truck uses a variable speed, high-rpm, low-torque engine whose nominal output approximates 25% of its peak output. Nominal output is defined as the amount of power the engine was designed to deliver for approximately 98% of its service life. The only time it’s expected to produce more… that wayward 2%… is when accelerating or climbing a hill. Once on the flats -- once you've reached a Stable State of cruise -- the figures are a good match. For hilly regions vehicle manufacturers offer different ratios for the rear-ends. Economy takes a hit but over-all, the figures match up. Respect an engine's Class of Service and you'll be rewarded with 2,000 to 5,000 hours between overhauls.
You can always demand more output from either type of engine but doing so will reduce it's service life. With a converted VW, for example, your Mean Time Before Failure will typically fall from about 2,000 hours in vehicular service to about 200 hours when powering a plane.
By comparison, an aircraft engine is a single-speed, low-rpm, high-torque engine whose nominal output approximates 75% of its peak output. Peak output may be defined further as maximum sustainable output, and as Peak-sub I, meaning an instantaneous value or dyno blip, something you might use to impress the newbies.
Since our goal is to produce thrust throuigh the rotation of a propeller, our primary interest is in the amount of torque that appears in the crank, and in the propeller's efficiency at a given rpm. The measurement of thrust is quite simple and articles describing different types of homebuilt thrust stands have appeared in the literature and on the internet. You will note that horsepower, which serves no useful function at this stage, has not been mentioned.
It usually takes an exchange of half a dozen messages or thereabouts to arrive at this point, if in fact we arrive at all. In the overwhelming majority of cases the Local Expert simply vanishes. Which is doubly unfortunate because the best is yet to come.
When we convert an auto engine for use in an airplane we are trying to convert it from one Class of Service to another to make it more suitable, usually in the area of mechanical reliability. By comparison, the typical flying Volkswagen starts out as a marginally suitable auto engine that is then made even less suitable for aircraft use by turning it into a hot-rod enigine. Why? Usually because the person doing the conversion has little understanding of an aircraft powerplant. Indeed, most such experts are merely the local Guru grown old, selling dune buggy engines to the kiddies. And after all, it does fly the plane, right?
So why even bother.
Well.... because we should. A properly built engine is more efficient. It produces the required torque at a lower rpm and wear increases exponentially with rpm. That means a properly built engine uses less fuel to deliver the same thrust and last longer, too.
But a properly built engine is also a lot less expensive to build and nowdays that's becoming a critical factor.
See that chart down there? The one title BORE VS STROKE? (It's embedded in the article in the blog; you guys on r.a.h. will have to go dig it out and print yourself a copy.) The chart shows the bore & stroke combinations for most common conversions and for everything using 88mm jugs or larger, or a 78 mm or longer crank, is going to have to machine the crankcase & heads to match. What they'll end up with is a dune-buggy combination -- a high-rpm engine that produces most of its torque up high. Itty-bitty toothpick of a prop. Not very efficient at all. Lots of machining to do. Lots of tricky bits to go wrong during assembly... which is why some folks don't even offer the thing assembled.
But it's all a bit of a joke because no matter HOW BIG the engine, it's MAXIMUM SUSTAINABLE OUTPUT is going to be between 35hp and 45hp.
Yeah, I know -- everybody is selling 80hp and up. Which is a dyno blip, not a steady output. Lotsa cubes is going to get you out of the weeds quicker but once you get the puppy cleaned up you're flying behind your basic 40hp engine, depending on the local atmosphere.
The limitation has to do with the heads, not the displacement. The cylinder heads only provide enough fin-area to manage the waste-heat from about 40hp. Unless its nice and cold or you are nice & high. But the dune crowd only knows how to build big-bore strokers.
Now go take anohter look at that chart. Limit your jugs to the stock 85.5mm.s and your cranshaft to a 78mm. At those sizes there's NO MACHINING REQUIRED. Your displacement is 1791cc, your maximum SUSTAINABLE output is about 45hp and your peak torque is going to come in at about 2800rpm.
Did I mention that no machining is required?
You've altered your cam timing but you're running a stock cam or a Schneider 'chugger,' the one used in the orchard-blower engine. You're running SINGLE PORT HEADS... because you're now an airplane engine, not a hot-rod. Your Volumetric Efficiency is pushing 70% and you're about a $1000 dollars ahead of the game because you haven't had to buy all that machining and you're using a higher percentage of stock, off the shelf parts. You're also running a longer, more efficient prop -- hopefully one you've carved yourself.
The thing starts on the first flip because it has an efficient ignition system, one that automatically adjusts itself to the load and a 20A. electrical system. But no starter, please. As it is, it weighs about twenty pounds less than any engine offered by anyone else.
But of course, it's not a dune-buggy engine. And the Instant Experts will stand in line to damn it with faint praise for that fact alone even while it flys circles around them and is still going strong when they're doing their second valve job of the year.
In my opinion, this is the perfect engine for an aerodynamically clean single-seater, like Bruce Kings little beauty. Had fate dealt me a different hand, that's what it would be going into. It would also be a good match for a KR-1, the early Jodel, Druine, the Teenie Two and similar designs.
Kill the parent, you got orphans. And that applies to engines, too.
-R.S.Hoover
Tuesday, July 15, 2008
Cancer's End-game
Being a disease of the blood, myeloma is highly mobile. Soon after the cancerous cells appear, they begin to spread, attacking the bone at new sites, which explains the multiple part of its name. Once established and able to spread, there is no cure. On average, you've got about three years to get your house in order.
Although there is no cure, radiation and a number of drugs have proven effective in slowing myeloma's spread. If the bone damage has not been too severe such treatment may buy you some time. Unfortunately, once attacked by myeloma our skeletons can not mend themselves. Some drugs are able to strengthen the remaining bony structure but rarely to the extent needed for pain-free mobility.
As you know, this all pretty new to me; there may be factors I've completely overlooked. But it wouild appear that working out a careful strategy of treatment offers a strong probability we can stabilize the affliction sufficiently to buy the time needed to finish a favorite project or to wrap up our affairs.
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I'm receiving radiation therapy at the local Cyberknife clinic, a neat little facility just minutes from our home where a computer-guided x-ray machine is used to kill the existing tumors a slice at a time. Doing so isolates the lesions and reduces the pain and no matter how you slice it, this story is really about the pain.
The location of the tumor(s) having been identified by prior x-ray and MRI scans, three dots of radio-opaque ink are tattooed on your belly allowing the system to realign itself with an accuracy of better than half a millimeter. The initial programming has defined the tumors as targets, determining the optimum amount of energy to deliver on each of three axies so as to limit the amount of damage to the healthy tissue. Hit the big red button and the system delivers its lethal barrage at the rate of several thousand hits per second, each precisely on target using feed-back from a separate x-ray camera to keep track of its progress.
The sessions, which are painless, take about fifteen minutes. They have scheduled one per day for the next couple of weeks with the option for a bit of sniper work toward the end.
At the same time, the physicians have been working out a chemical attack to compliment the radiation barrage. X-rays and other forms of imaging provides some of the feed-back needed to guide the chemical attack but the most useful information is derived from a series of vampire strikes to monitor the chemistry of my bloodstream. These procedures are slower than the dramatic strikes from the Cyberknifes linear accelerator but infinitely more subtle, capable (in theory) of tracking down a single cancerous cell.
-R.S.Hoover
Thursday, July 10, 2008
Doing Your Vitals
Blood Pressure
Pulse Rate
Respiration Rate
Body Temperature
Height
Weight... and so forth.
That last ...and so forth... looks unscientific as hell but it makes sense to a kid. Along one wall each student had a list showing our body weight, height, color of hair & eyes and several other data elements, some not specific to human vital signs but all of profound interest to a gaggle of eight year olds.
Even more interesting is the fact we collected the data ourselves. And if you think that's a Big Deal, it's not. In fact everyone should be able to not only define their vitals but should have no trouble collecting such data and recording it in a tabular fashion.
Because that's what you do when you get sick.
Ecept nowadays, most folks don't. In the modern world you simply plug yourself into your computer and let it collect your vitals automatically. That guarantees less chance of making an error when you collect the data but it also ensures more uniform reporting. It also guarantees the data will be communicated to whoever needs it.
Which is why you could have knocked me over with a feather when a local 'health care worker' shows up to 'record' my vital signs.
Mebbe when digging the Panama Canal but definitely not in the 21st Century. By the time the 'health care worker' has driven to your home, imposed themselves on you, recorded your vitals -- correctly, I hope -- you are looking at a significant cost in time and gasoline.
-R.S.Hoover
Saturday, July 5, 2008
Cancer
No, you can't have it. You have to grow your own. You don't catch cancer. It's not a head-cold or a case of clap. I've been working on mine for more than five years now. It's called Multiple Myeloma and it has lead me a merry chase, partly because the first symptoms appeared as a kind of transition variety and all those fancy, infallible scanners and CATZ and PETZ and sooper-dooper hi-teck never-wrong space-age machines were DEAD WRONG. Indeed, I was I was healthy as hell according to them... and they were right. Unfortunately I was in the process of developing multiple myeloma so that while I was healthy then, within a matter of weeks I was now not... even though I had just completed a series of expensive, time-consuming tests that said I was.
One of the trickier bits about Multiple Myeloma is that it likes to attack people who are about forty years of age or older. Need I mention that includes a lot of pilots?
If you just found out you've got it, you're one of about 15,000 others in the 40 - to - 65 age-group who joined that years club. After getting the good news an awful lot of these guys make it as far as the parking lot before blowing out their brains. I mean, after all... they've just lost their ticket, everyone is moving to larger airframes rather than smaller ones and career-wise our boy is on the lower cusp, for whom a lab report ...perhaps accompanied by a friendly tranquilzer... has just guaranteed the world as he knew it has ended.
Okay, stats vary and I don't want it to appear worse than it is but I've had the misforturne to see this scenario played-out twice, up-close and personal. My own situation aside, I'd rather it didn't happen again so howzabout following me through on this one?
The Biggie is that some forms of multiple myeloma are TREATABLE. Okay, so there's no ATR in your wallet when you get done but at least you are still there.
Treatable means you can't have my plane... go build your own. But we -- and I'm talking the aviation community, your family and what all -- we've still got you. That puts us miles ahead of the game. So don't get all teary-eyed on me. You've still got the Big C! (and so do I). It's awful. It F**king Hurts! It's NOT FAIR!!
So suck it up and let's get on with our lives.
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Like I said, some forms of multiple myeloma are treatable and I'm a living example of someone who has just started through the process. I've done the wet hanky bit, hid in the corner for a major bout of boo-hoo's, then then did the Oh So Sorry me but my God that sonofabitch hurts!
Weak as a cat, too. (But I'm working on that.)
Kinda confused. Chemotheropy guarantees you're going to kinda dingy now & then but but trust me, I passes.
What you need, right now and for a good while to come is your friends. And you can go ahead and count me in, if I'm not already on the list. Because with multiple myeloma the emphasis is NOT about grabbing your friends by the handles and dumping them in a hole in the ground, it is about getting BETTER; about HEALING. And I'm not standing here blowing smoke. Hell, I'm still making rigs for Chugger's wing ! (and no tranks in the pill compartment this morning).
(And I've still got three damn engines to finish :-)
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So what about you guys who don't have 'chugger' waiting in the wings? Then you're going to have to get one... or something damn near identical.
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Plus you've got to learn how to SLEEP.
Deep, rich rewarding SLEEP. Because based on my limited (but growning experience as a cancer victim) sleep appears to be the catylyst for cure -- or at least for healing. The only problem is that everything is all so new (!) and there is so much to learn. To make matters worse you usually look like the dog's dinner and feel even worse.
Tough Darts.
About half the time, multiple myeloma is trying to kill you on purpose and the rest of the time it does a fair amount of damage through pure chance, all the while you are rattling like a goard from all the pills you've stuffed yourself with. Most of the pills are an effort to control the pain, others are there to help control the side-effects of the chemicals that are suposed to help you GET WELL and a very critical aspect of that effort is the need to maintain accurate records. The records are needed to maintain the proper balance between pain management and chemotherapy. Need I mention that if you aren't a good clerk at the outset you'll soon become one!
So what works? What's the Secret Weapon?
I haven't the foggiest notion.
But I do know that Jesus never owned a Cadilliac and Mohammad had never actually seen a real oil well although it's fair to assume both enjoyed a wealth of real friends, the kind you can't buy.
So let's start with that
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29 June -- Home from the hospital, I pretty much lived in this chair for three days & nights because it simply hurt too much to lay down. We finally got that worked out .
You can't deal with the tumor until you've figured out some way to deal with the pain.
