An engineer's pad. Not a lonely apartment filled with Star Trek posters, computer parts and mismatched dirty laundry. The beautiful, pale green quad-lined paper that we used in college. I loved that stuff. I still remember with fondness the strict rules we were to follow when working problems on this magical media. All of my Statics and Dynamics instructors were from the Middle East, and initially came across as very stern. Only after a few weeks into the semester did they loosen up and crack a few smiles. By that time, they had scared off the faint of heart (also known as "business majors".)
The discipline of how to solve a problem all started with how to write it down on the page. Presenting the problem, listing the equations that might apply, stating assumptions, drawing a diagram, developing the Free Body Diagram, showing every step as you used the known to isolate and eliminate the unknown. Every time I see an engineering pad I want to start solving a problem....
Quick update on the hovercraft: Board corners rounded and sanded, edge of board covered with duct tape, hole and duct work in place and the construction adhesive is curing (can't wait to see how well that works.) Next step is to install the "skirt" and grommet and then strap down the blower. Shouldn't be long now.
Java classes going well. Down to single digits on the lectures and the separate "hands on" videos. And I've decided on my first project. I'm going to develop a program to let my 10-year old practice his multiplication and division. I've got some fun ideas on how to keep him engaged and learning. And since the program will have a "test" module, we can tie a healthy incentive to the results. Clear goals and a controlled environment should go a long way. Maybe I'll even give him his own engineering pad once he aces the test!
Sunday, July 25, 2010
Monday, July 19, 2010
I Have a Dream
Well, actually I have a lot of dreams. There was a forgettable movie that came out in 1989 called, Dad. I say it was forgettable, because for most people it was, but part of it struck a chord with me. It was about an old man, played by Jack Lemmon, that was coming to the end of his life. Through a traumatic event, his son comes to learn that his father has spent most of his life subconsciously developing a fantasy world within his imagination. He evolved this fantasy day after day, growing an incredibly detailed alternate reality for himself to escape the harsh realities of his real life.
I really don’t have too many harsh realities in my file, but I do spend a lot of time in my own head. And I do have a tendency to develop a “thread” pretty thoroughly. My favorite is my version of the “what superpower would you like to have” question. My answer to that question is that I would like the ability to travel back in time and study with the master of any particular skill, art or science and then return to my time. So, if I’m about to get jumped by four guys that want my iPhone, I would travel back to the late 60’s and study Jeet Kune Do at the hands of Bruce Lee. After a few months or years of this, I would pop back in and take care of business, none the older for the journey. Similarly, if I get annoyed at the profusion of computer technology that is leaving me behind, I might skip to a garage in the Santa Clara Valley and insinuate myself into the process of putting together the first PC’s.
I’ve had these fantasies for a long time (well before Heroes came out), and as I said, they tend to get pretty detailed. I’ve always thought this tied into my ability to plan in the real world as well. It’s like using the power in reverse. When I plan a project or event, I imagine it in great detail. I review the environment and facilities. I see the people and how they act and interact. I envision all the little steps. I usually go through many permutations in my mind. And it’s different than just thinking about it; it’s more like simulating the event.
I listened to a Podcast recently by one of the founders of Palm and MindSpring. He researches the human brain when he’s not making millions of dollars on startup companies. As best I could understand him, he believes that the brain works by storing memories, and then making predictions based on the available data. I think if you boil it down to its simplest form, that’s what learning is. It gives you a template of past experiences to compare to current or future situations.
How does any of this relate to engineers? Well, I don’t know. But in my experience, the best engineers can visualize a problem. Sometimes their perspective is too narrow, and they only visualize the technical aspects of a situation. Maybe we all need to spend more time fantasizing, looking either backward or forward.
I really don’t have too many harsh realities in my file, but I do spend a lot of time in my own head. And I do have a tendency to develop a “thread” pretty thoroughly. My favorite is my version of the “what superpower would you like to have” question. My answer to that question is that I would like the ability to travel back in time and study with the master of any particular skill, art or science and then return to my time. So, if I’m about to get jumped by four guys that want my iPhone, I would travel back to the late 60’s and study Jeet Kune Do at the hands of Bruce Lee. After a few months or years of this, I would pop back in and take care of business, none the older for the journey. Similarly, if I get annoyed at the profusion of computer technology that is leaving me behind, I might skip to a garage in the Santa Clara Valley and insinuate myself into the process of putting together the first PC’s.
I’ve had these fantasies for a long time (well before Heroes came out), and as I said, they tend to get pretty detailed. I’ve always thought this tied into my ability to plan in the real world as well. It’s like using the power in reverse. When I plan a project or event, I imagine it in great detail. I review the environment and facilities. I see the people and how they act and interact. I envision all the little steps. I usually go through many permutations in my mind. And it’s different than just thinking about it; it’s more like simulating the event.
I listened to a Podcast recently by one of the founders of Palm and MindSpring. He researches the human brain when he’s not making millions of dollars on startup companies. As best I could understand him, he believes that the brain works by storing memories, and then making predictions based on the available data. I think if you boil it down to its simplest form, that’s what learning is. It gives you a template of past experiences to compare to current or future situations.
How does any of this relate to engineers? Well, I don’t know. But in my experience, the best engineers can visualize a problem. Sometimes their perspective is too narrow, and they only visualize the technical aspects of a situation. Maybe we all need to spend more time fantasizing, looking either backward or forward.
Saturday, July 17, 2010
Saturday for Engineers
Okay, I realize a lot of engineers have a real life. Some of your probably spent today at the lake, or playing softball or going to a movie. Here's what I did.
First, I went to work to try to catch up on all the things that didn't get done during the week. My Inbox is sacred. I'm not one of those people that can delete emails without reading them. And if it is in my Inbox after I've read it, then I've got something that must be done....Yeah, I'm a little sick, but I'm working on it.
Luckily the normal "to do's" were interrupted by a request to come look at some parts in the shop. So I looked at a couple of large composite parts. One was up for a part in "Cutter's Gone Wild" (trim problem) and the other had "resin starvation" issues. I'm not a Liaison Engineer, but I manage a few (does that sound like a Holiday Inn commercial?) And I'm not a composite expert yet either, although I did start my career on the B-2 Stealth Bomber, so I do have some experience. I should blog about the B-2 some time; secret programs are always good for a lot of laughs.
So after work (and a bit of River Running for exercise) I had the afternoon in front of me. My options were to watch "Paul Blart, Mall Cop" on NetFlix with the family, or do something that would not cause my brain to melt out through my ears. So, I threw on my best weekend T-shirt (the Avengers leaping right out of my chest), grabbed my laptop and headed for the library. Not to check out books of course; I just needed a quite place to work.
I've reached the point in my Java class that I really had to find a way to get some programs running. The Stanford iTunes class is great for learning the principles, but doesn't get into the nuts and bolts of using the development environment that they recommend for the class. Luckily, I found another set of videos that focus on the nuts and bolts. So I made some progress this afternoon. I'm going to master this Java thing; it's just a matter of time.
After I got tired of Java I moved on to a Strength of Materials class I've started, also on iTunes. This one is through Michigan Tech. So far it looks like it is going to cover my interests and be pretty challenging.
Now it's about time to pack up the computer and head back home. If Paul Blart is done entertaining my family, it's time to make some progress on the hovercraft. Ten year-olds don't forget things like that...
First, I went to work to try to catch up on all the things that didn't get done during the week. My Inbox is sacred. I'm not one of those people that can delete emails without reading them. And if it is in my Inbox after I've read it, then I've got something that must be done....Yeah, I'm a little sick, but I'm working on it.
Luckily the normal "to do's" were interrupted by a request to come look at some parts in the shop. So I looked at a couple of large composite parts. One was up for a part in "Cutter's Gone Wild" (trim problem) and the other had "resin starvation" issues. I'm not a Liaison Engineer, but I manage a few (does that sound like a Holiday Inn commercial?) And I'm not a composite expert yet either, although I did start my career on the B-2 Stealth Bomber, so I do have some experience. I should blog about the B-2 some time; secret programs are always good for a lot of laughs.
So after work (and a bit of River Running for exercise) I had the afternoon in front of me. My options were to watch "Paul Blart, Mall Cop" on NetFlix with the family, or do something that would not cause my brain to melt out through my ears. So, I threw on my best weekend T-shirt (the Avengers leaping right out of my chest), grabbed my laptop and headed for the library. Not to check out books of course; I just needed a quite place to work.
I've reached the point in my Java class that I really had to find a way to get some programs running. The Stanford iTunes class is great for learning the principles, but doesn't get into the nuts and bolts of using the development environment that they recommend for the class. Luckily, I found another set of videos that focus on the nuts and bolts. So I made some progress this afternoon. I'm going to master this Java thing; it's just a matter of time.
After I got tired of Java I moved on to a Strength of Materials class I've started, also on iTunes. This one is through Michigan Tech. So far it looks like it is going to cover my interests and be pretty challenging.
Now it's about time to pack up the computer and head back home. If Paul Blart is done entertaining my family, it's time to make some progress on the hovercraft. Ten year-olds don't forget things like that...
Wednesday, July 14, 2010
Bird Strike Tests
I was recently introduced to a subject of which I had previously been blissfully ignorant. Sure, I knew in general about bird strike tests. What engineer hasn't chuckled at the tale of a chicken passing effortlessly through an aircraft windshield because the testers forgot to thaw it out?
Lucky me, I recently had the good fortune of watching several shots using freshly "euthanized" chickens. No fear of these birds being frozen. It was so hot there was an evaporative fan keeping them cool. No such luck for the test observers. The reason for the fans was not only to keep the chickens alive, but also to make sure they didn't lose too much weight in the hot southwest sun. That's because they had to be within a certain weight in order for the test to be valid, and you can only make minor adjustments by injecting fluid or clipping off toes. These tests can also be performed using gel packs, but not all certifying agencies will accept them (the argument is that the consistency is not enough like a bird).
There is also a velocity requirement for the bird hitting the target. What is the target speed? Well, it depends. A lot. On what does it depend, you might ask? Good question. Depends on the certifying agency and the intended use. If that sounds vague, then you are doing a good job keeping up with me. So through some less-than-exact science, a target weight and velocity are determined. It is not clear exactly how the OEM is supposed to insure that no over-weight, or fast flying birds stray into the flight path of the craft once it has been certified to a lesser threat.
And since we have requirements, we have to have tolerances. The birds are weighed to the gram and adjusted appropriately. The velocity tolerance is normally around 2-percent of the target speed. So, now we are ready to perform a test. We have a recently deceased chicken that weighs maybe anywhere from 3 - 7 lbs (depending on your requirements), but is weighed to the gram. We then attempt to push this chicken through a 30' tube using compressed nitrogen (think "punkin chunkin") and hit a target within a few inches at a speed within a few MPH (or knots). If your strike is too slow, it doesn't count. If it is too fast, and you break something, your test is worthless. If you happen to be outside, your shots will be affected by the temperature AND you will have to maintain your test article at a specific temperature. Even if you are inside, chicken chunkin is not a highly repeatable process.
Which brings me to my point (Ha, I bet you thought I didn't have one!) As a person new to this process, I'd just like to say, "Are you people crazy!" What bunch of eggheads dreamed up this process, and have you not stepped back in the last 3 or 4 decades to see what a ridiculous house of cards you have built? One of the first things we learn as engineers is the concept of significant digits. If you are using data with only one decimal of accuracy, your answer can never be any better than one decimal. But the aerospace industry is spending millions of dollars every year shooting chickens out of a cannon trying to meet requirements that all started with someone's best guess about what size bird will hit a plane at a predetermined velocity. With that kind of fidelity as the input, we are wasting a lot of resources trying to introduce chickens to windshields. Develop a standard impact test that can be performed in a lab. Use energy calculations. Come on people! And to the guys that think a gel pack can't be made to adequately represent a bird, I say let's talk about Neal Armstrong walking on the moon. Or let's talk about the fact that I have a 99-cent App on my iPhone that emulates my HP 41CV. Seriously, we aren't smart enough to do better than chicken chuckin? I don't believe it.
Lucky me, I recently had the good fortune of watching several shots using freshly "euthanized" chickens. No fear of these birds being frozen. It was so hot there was an evaporative fan keeping them cool. No such luck for the test observers. The reason for the fans was not only to keep the chickens alive, but also to make sure they didn't lose too much weight in the hot southwest sun. That's because they had to be within a certain weight in order for the test to be valid, and you can only make minor adjustments by injecting fluid or clipping off toes. These tests can also be performed using gel packs, but not all certifying agencies will accept them (the argument is that the consistency is not enough like a bird).
There is also a velocity requirement for the bird hitting the target. What is the target speed? Well, it depends. A lot. On what does it depend, you might ask? Good question. Depends on the certifying agency and the intended use. If that sounds vague, then you are doing a good job keeping up with me. So through some less-than-exact science, a target weight and velocity are determined. It is not clear exactly how the OEM is supposed to insure that no over-weight, or fast flying birds stray into the flight path of the craft once it has been certified to a lesser threat.
And since we have requirements, we have to have tolerances. The birds are weighed to the gram and adjusted appropriately. The velocity tolerance is normally around 2-percent of the target speed. So, now we are ready to perform a test. We have a recently deceased chicken that weighs maybe anywhere from 3 - 7 lbs (depending on your requirements), but is weighed to the gram. We then attempt to push this chicken through a 30' tube using compressed nitrogen (think "punkin chunkin") and hit a target within a few inches at a speed within a few MPH (or knots). If your strike is too slow, it doesn't count. If it is too fast, and you break something, your test is worthless. If you happen to be outside, your shots will be affected by the temperature AND you will have to maintain your test article at a specific temperature. Even if you are inside, chicken chunkin is not a highly repeatable process.
Which brings me to my point (Ha, I bet you thought I didn't have one!) As a person new to this process, I'd just like to say, "Are you people crazy!" What bunch of eggheads dreamed up this process, and have you not stepped back in the last 3 or 4 decades to see what a ridiculous house of cards you have built? One of the first things we learn as engineers is the concept of significant digits. If you are using data with only one decimal of accuracy, your answer can never be any better than one decimal. But the aerospace industry is spending millions of dollars every year shooting chickens out of a cannon trying to meet requirements that all started with someone's best guess about what size bird will hit a plane at a predetermined velocity. With that kind of fidelity as the input, we are wasting a lot of resources trying to introduce chickens to windshields. Develop a standard impact test that can be performed in a lab. Use energy calculations. Come on people! And to the guys that think a gel pack can't be made to adequately represent a bird, I say let's talk about Neal Armstrong walking on the moon. Or let's talk about the fact that I have a 99-cent App on my iPhone that emulates my HP 41CV. Seriously, we aren't smart enough to do better than chicken chuckin? I don't believe it.
Tuesday, July 13, 2010
FBD
Just in case I was too vague earlier, an FBD is a "Free Body Diagram". This is one of the fundamental tools of an engineer, but seemingly it is becoming a "lost art." Most of the younger engineers I work with don't seem to appreciate or be able to use them effectively, which is a real problem. With the advent of so much graphics and analysis software, they don't seem to grasp the fundamentals, or even why they are important. (Wow it really makes me feel old to talk about "the younger generation.")
My favorite t-shirt of all time: a picture of Clint Eastwood in one of his tough spaghetti western outfits, like in Hang 'em High, or High Plains Drifter.... and the caption reads, "Free Body Diagram, or Die!" I've only seen the t-shirt once, and I'm jealous.
My favorite t-shirt of all time: a picture of Clint Eastwood in one of his tough spaghetti western outfits, like in Hang 'em High, or High Plains Drifter.... and the caption reads, "Free Body Diagram, or Die!" I've only seen the t-shirt once, and I'm jealous.
I'm Baaaack (read in a Jack Nicholson crazy voice)
Ok, I have a confession (aside from the fact that I hate the Times Roman font.) I stopped blogging for a couple of weeks for two reasons. One, I was in the southwest, trying to shoot chickens at a helicopter cockpit. More about that later. But the second reason is that the only feedback I've had was from my family, who told me it is too hard to post comments on my blog. Going completely open-loop just wasn't working for me. But I was told today that at least other person that knows what a FBD is might have seen this blog and enjoyed it. So that gives me a little encouragement. It was also brought to my attention that since I don't have a counter set up, I really have no idea how many people may have seen it. (duh!)
So, I'll bring my blog up to date, and then try to keep it reasonably current. What's new? I'm half way through the 28 lectures in the Java class I'm "taking" through the Stanford iTunes University. I still think it's great, but I could use some help on a few PC-specific issues if anyone wants to chime in. (And did I mention I'll never buy a 64-bit PC again? Well, it bears repeating.)
So, I'll bring my blog up to date, and then try to keep it reasonably current. What's new? I'm half way through the 28 lectures in the Java class I'm "taking" through the Stanford iTunes University. I still think it's great, but I could use some help on a few PC-specific issues if anyone wants to chime in. (And did I mention I'll never buy a 64-bit PC again? Well, it bears repeating.)
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