Download
1 / 38
380 likes | 572 Vues
Engineering 181 Lab Session One: Introduction to Engineering Design and the Kodak Single Use Camera. How will the lab sessions work?. We’ll begin with a short lecture Lab work will be done in groups of four Structured exercise during lab hours Extra work to do outside lab hours
E N D
Engineering 181 Lab Session One:Introduction to Engineering Designand the Kodak Single Use Camera
How will the lab sessions work? • We’ll begin with a short lecture • Lab work will be done in groups of four • Structured exercise during lab hours • Extra work to do outside lab hours • Every lab has a report due one week later • The emphasis is on working in groups
Two major projects this quarter: • The first five weeks will concentrate on the Kodak single use camera: mechanisms, optics, electronics, and manufacturing. • The second five weeks will examine your bicycle: structures, materials, testing, and manufacturing.
Goals for both lab projects: • To understand how designers think • To gain some feel for what a “good” design entails • To begin to learn how we can analyze designs and improve on them.
What you can expect from us: • To be on time and prepared to teach. • To be interested in what we’re talking to you about. • To be willing and available to discuss the material, answer questions, and help you get started in engineering at Ohio State. • To get your assignments graded quickly.
What we expect from you: • To be on time for class, and prepared to take part in the labs; • To pay attention during lectures; • To prepare ahead of time when asked; • To carry your share of the load in your group. • To complete your assignments.
A word about credit hours: This class is likely to take as much time as many of your five credit hour courses. This isn’t unusual for engineering courses, because we have a lot to teach, and only four years (+) to do it. This is part of the price you pay for being in the best college at OSU.
Let’s begin with a simple question: What is engineering??
One possible answer, from theOxford English Dictionary: Engineering is: i) “the application of science for directly useful purposes…” ii) “the action of working artfully to bring something about…”
Which raises some other questions: • Is engineering just “applied science”? • Is the engineer’s job the same as the scientists? Engineers and scientists both solve problems, right? • If that’s the case, why are we in separate colleges at OSU?
If engineers are just “problem solvers”, then how are we different from physicists, stock brokers, or mathematicians? • And while we’re on the subject, aren’t engineers famous for creating as many problems as they solve?
Is there anything essential about what engineers do that would clearly separate us from every other profession?
Yes, there is: engineers generally are interested in creating something new and different, based on what we know (or think we know) to be true about the physical world. The word that gets used a lot in this context is design.
A working definition of engineering: • “Engineering is design performed in the presence of limiting factors and conditions.” • Design is the key: as engineers, we’re about creating new things, based on our understanding of the physical world.
What kinds of things do we design? • A new bridge on Lane Avenue (CE, WE); • A racing bicycle (ME, MSE, ISE, ChemE) • A fuel cell for NASA (Aero, ChemE, EE) • A new operating system (EE, CSE) • The key point: in every case, it’s new and somehow different than what came before.
However, it’s almost never the case that our ideas are totally new. Almost every engineered object is an improvement or a refinement of someone else’s bright idea. A few “for instances”…
A weather satellite for a neighboring planet… (arrived Thursday)
How about a robot explorer for that same neighboring planet?
Good engineers and designers constantly look around to see what other smart folks have done, before they begin to work. • This avoids the problem of “reinventing the wheel”. (This technique is called “reverse engineering”, or less politely, “stealing”.)
When we talk about figuring out how the world works, we use the word, analysis. • You’re going to spend a lot of time during the next four (or five) years here learning to analyze problems, situations, designs, and ideas.
Analysis is crucial to engineering: without our tools for doing analysis, we’re not really engineering, we’re just guessing. • One thing that sets engineers apart from normal people is our penchant for attaching numbers to things… and we have a lot of ways to do that…
However, analysis alone isn’t engineering, it’s science. • (Warning: this is one professor’s view.) • It’s when we use analysis to help us create something new, that we’re actually engaged in the other side of engineering, synthesis.
Synthesis: • A five-dollar professor-word for “design”. • It’s what we do when we put our analytic skills and our ideas to work creating something new. • It’s what sets us apart from most of the rest of the world...
How about limiting factors? • Usually we think of natural laws, but often the really severe limits are imposed by our fellow humans. • We call these limiting factors constraints, because they constrain our designs in some way. • Sometimes we see them ahead of time, sometimes we don’t…
Some typical kinds of constraints: • Performance • weight • speed • rigidity • Cost • Material • ??
Another example: • The lowly, much neglected, two piece aluminum can…
Some questions to ask about any design: • What were the constraints? • How well did the designers deal with them? • Did they overlook any? • What tradeoffs did they make? • How could we design it better?
Reverse engineering: • When we take another design apart to figure out how it works, and how the designers solved the constraint problems, we’re doing reverse engineering. • In this class, that’s what we’ll be doing for the next few weeks with the Kodak Camera.
Kodak Single Use Camera: • What constrains this design? • Performance • Economics • Materials • Production • ???
What we’ll do today: • Take some photos with the camera for use in Labs Two and Four. • We’ll use these photos later to estimate: • Shutter speed • Flash duration • Focal length of the lens • Depth of field of the lens
Shutter and flash speed estimation: • Today: take photos of bike wheels • without using the flash (cover the flash window!) • with the flash • Develop your film this week, and bring the photos with you to class next week. • Knowing the wheel speed, we can estimate the shutter speed and flash duration.
Depth of field and focal length: • Today: take photos of meter bars at known locations. • Develop film this week. • Bring photos to Lab Three to determine focal length and depth of field.
Procedure for today: • Find your name at one of the tables, and introduce yourself to your group; • Form three “supergroups” of three small groups; • Each supergroup will rotate between the two bikes and the meter bars. • Make sure you get photos of both bikes and the meter bars before you leave!
One word of warning: • Bring the camera and photos with you to lab next week, when we’ll take the camera apart. • Do not take the camera apart yourself ahead of time! It contains a capacitor charged with 330 volts, and it can give you a nasty shock if you touch it!
