Pop!

There is so much to talk about and no time with which to talk about it right now. Here, in fact, is a list. I'll talk briefly about some things in this post, and may expound on some in later posts; leave a comment if you want to hear more about anything in particular.

• Friday was the Barnstormers' trip out to Edwards Air Force Base.
• Saturday Proctor Elaine set up a trip for a bunch of us to go to some hot springs.
• Sunday I went to USC for the Intercollegiate Swing Dance Challenge my sister organized.
• Clinic:
• Code Freeze was on Tuesday
• Final report rough draft is due Friday
• Next Presentation is on next Tuesday
• Graduation is in less than a month.

First, the Edwards trip. I have a difficult time expressing how cool last Friday was. We got to fly the F-16 simulator, then at the end of the day we got to walk around the F-16 flightline and see the real F-16s up close and personal. Our guide, Nate Cook (HMC class of '95), told us what each new thing on the F-16 was and then took us into the hangar and showed us some dummy bombs that they have for testing. He talked to us about the difference between dumb bombs, which are purely ballistic, and smart bombs, which guide themselves in to their target. We got to see the Global Hawks in their hangar. One of them was fueled and it's impressive how much droop the weight of the fuel causes in the wings.

The trip to the hot springs was quite lovely; the springs themselves are at the end of a mile-and-a-half hike. I was getting nervous hiking all that way through weather somewhere in the 90s, but the springs are right on the bank of a creek that was flowing with frigid water, and we actually had to cross the creek to get to the hot water. That was a nice, refreshing end to the hike before we went to relax in the springs. I now have a lovely peeling sunburn across my upper back. It has a hand-print on the back of my left shoulder, where I could reach.

My sister called me to find out if anyone from Claremont was coming to her Swing Challenge at USC (she's the president of their swing club and has been working on making this happen for several months). I asked some of the dancers here and then told her that no, the Claremont Colleges Ballroom Dance Company (CCBDC) had not heard. She asked if they were the right people. After all, this was a swing competition. At Claremont, I assured her, "Ballroom" means "Dancing with Partners" instead of "Waltz, etc." (those five are more properly the "Standard Dances").

It ended up that most of the company members had practice that night, but one girl and I were able to make it, so the two of us represented Claremont in the Jack and Jill challenge. A Jack and Jill is a swing competition in which each person dances with another, chosen mostly at random (leads and follows dance with a partner of the opposite type). I didn't get through the first round (11 leads, and all of them way outclassed me) but I had a great time anyway. Our other Claremont rep took 5th place, though!

For now, that's it. I'll talk more about clinic when I don't have to be doing it quite as much.

~KMarsh

Tools: Now with 100% more Photographs!

Okay, so it's just two, but hey, that's infinitely better than none. I've even got some mathematicians here to prove it. I have leftover pieces of stock for my screwdriver, so I can give you a before and after picture of that, although I don't have any intermediate pictures:
The cylinder on the far left is the acrylic stock for the handle. To prepare it, you need to face the ends (scrape off the rough edges made by sawing it off from the rest of the stock) and drill the central hole for the blade to go into. Both those steps are done using the lathe (drilling on the lathe will always feel odd to me, since it's the part that is spinning, not the drill bit). Next you use the lathe to carve out the cone. The milling machine then bores out the six flutes along the length of the handle, and it's back to the lathe to file the dome on the end into shape.

Finally the entire thing is polished -- first you sand it with coarse-grit sandpaper, then with two or three finer grades of sandpaper until you finish off by rubbing it down with toothpaste using a sock. If you do it right and put some elbow grease into it you'll get nearly a mirror finish to the plastic which is quite remarkable to see: scratches from machining the handle make the surface of the acrylic very cloudy and it looks like it will never again be as clear as the stock you were given.

The blade is placed into a holder that keeps it at the proper angle for machining the tip, the mill is used to take off the material from one side of the blade and then you flip the whole thing over in the jig to machine the other side. The other end is then faced to length on the mill and a tiny hole is drilled right in the very center of the blade near one end. A matching hole is drilled in the handle and the blade slides in and is held in place with a small pin. Before assembling the screwdriver, the blade is heat treated to increase its hardness and toughness and then polished in a sandblaster.

The hammer, shown disassembled with each piece next to a piece of stock where available, is a much more demanding tool, owing mostly to its increased complexity.
This is a machinist's hammer, not a claw hammer, and it has two faces: a soft face made out of nylon for easily-damaged pieces and a hard-face for driving nails and other more traditional hammer tasks. The first piece I made was the hard face. The hard face is made of AISI 4340 carbon steel and machined entirely on the lathe. After machining it is heat treated just like the screwdriver blade. The 4340 steel is quite hard to begin with and is much more difficult to machine than any of the other materials we use in this class.

After working with the hard face, machining the nylon for the soft face felt like butter. There wasn't much to do for this beyond facing it and reducing the diameter. The only noteworthy part was tapping the hole drilled in the back side so that we can easily thread a set screw into it to hold it on to the hammer head.

The hammer head required quite a bit of machining, both on the lathe and the mill. It's made of AISI 1015 steel, though, and is much easier to work with than the hard face. First it must be faced and the smaller diameters must be reduced on the lathe. Then a hole must be drilled and tapped and a "spotface" (very small washer-like indentation against the face of the piece) produced for the nylon soft face to attach to. The other side is drilled out, then reamed to a very tight specification so that the hard face can press-fit into it and hold without slipping out. That hole has a countersink bored into it to make room for the chamfer on the hard face between the two diameters. The head is transferred to the mill where the flats are cut on the sides and the slot for the handle is bored.

Finally, the handle is worked from a piece of wood and the entire thing is assembled. To hold the handle in the head a slot is cut in the top of the handle and a wedge driven between the two pieces of the slot. The spec-sheet says that the wedge is made out of "Red Devil #4" which has defied my preliminary attempts to define.

Moral of the story: take a machine shop class. It's fun, and amazingly useful even if you never step inside a shop again.

~Kyle Marsh

April crunchtimes brings May graduations?

One of my professors just called April the worst month of the year. I had never thought of it that way, but in a way it is, and has been since I was maybe 10 or so. The second half of spring semester always comes upon us suddenly: it's staggering (and more than slightly terrifying, truth be told) to think that I only have 6 weeks of school left: 4 weeks of classes, projects week (finals week, too, for seniors), and an empty week (finals week for the rest of the school).

The downside of this, of course, is the 4 weeks I have to get EVERYTHING done. That includes my Computer Vision independent study, Clinic, Clinic presentation, Clinic poster, Clinic report, Photography, Philosophy of Mind, and tools.

Tools is my current favorite. I'm making my hammer now, and I just finished all the work that I need to do on the metal lathe. A quick search of my archives tells me that I haven't actually talked about tools yet, which is strange since I really enjoy it and I'm taking it for pure enjoyment. Tools, or E-8, is one of the first engineering classes that prospective engineering students take at Mudd. It's the introductory shop course, called "Tools" because that's what you build. You use the sheet-metal shop to craft a tool tray, bending, cutting and welding sheet metal into shape. You use the metal shop to build a flat head screwdriver, and most of a machinist's hammer (something like this, with one face made of nylon and the other of hardened steel). You use the wood shop to build the hammer handle.

I have not yet made my tool tray, but I've finished my screwdriver and much of my hammer. The screwdriver handle is made from acrylic using the lathe and the mill, and the blade is made on the mill. The hammer is the most complex piece. The hammer head (a short piece of 1in steel bar stock) is machined on the lathe and mill to fit the handle and both faces. The handle is made with the band-saw and wood lathe followed by a LOT of sanding. The hard face is machined from carbon steel on the lathe, followed by some filing, and then heat treated to bring it up to full hardness. It's polished by sand-blasting and fits into the head by press-fitting. The soft face is made from nylon (the nicest material I've worked with on the lathe) and attaches to the head with a screw. I'll post pictures of my pieces when I get off my butt and take some pictures (possibly tomorrow).

The shop proctors tried to chastise me when I told them (on, say, Wednesday night) that I hadn't started my hammer yet (due Friday of the following week). I corrected them. I am not a sophomore engineering student with no time. I'm a senior computer science student taking this class for fun. I can be in the shop every morning for 3 hours if I feel like it, and if I don't feel like it, I can drop the class (HMC's drop date is insanely late in the semester) or turn in half a hammer. It's a good way to approach the class.

In other news, I photoshopped up my senior page for the yearbook yesterday. Each senior gets a full page in the yearbook to decorate as desired, so I sifted through my (meagre) photo collection and placed the pictures on a canvas in Photoshop.
The pictures include me eating a Chinese-Donut-Burger, my barnstormers co-president, my girlfriend, my roommate (first three years; we have singles now), a prank some friends and I pulled, a prank some friends pulled on me, a few Halloween costumes (I'm the Rorschach near the top), me getting my head shaved for a friend who had cancer sophomore year (he's doing fine and back at school), the boxers a friend decided to hang on her wall after finding them in her laundry, the Mudd Amateur Rocketry Club at ROCStock a few years ago, Iris Critchell with her Cessna 172, and Rotsnake. And lots of gratuitous Photoshop effects.

I discovered Photoshop brush packs. Thus I have a coffee stain, ink stain, and crinkled-paper effects. The torn edges, actually, are incredibly simple to do in newer versions of Photoshop: turn on layer-effects and add a drop shadow, inner glow and outer glow to the layer. That gives the very slight drop-shadow to create some depth in the image and a thin white border to each picture. Take the eraser tool and grab a ragged brush, then erase the corners/edges of the photo. The white border now looks like torn paper where you've erased the image. I used this to create pinholes, torn corners where pushpins may have been ripped out, and half-ripped photographs. Putting the whole thing on a wooden surface gave it a bit more context, and I couldn't resist the coffee stain. The tape strikes me as a bit cheesy, but not too much and I had just learned how to make the tape.

As for post-graduation plans, I'm not sure yet where I'll be working; I have an offer from DreamHost, and I'm waiting on a few more. I'll probably take the summer off, though, and start in the fall. Over the summer I think I might take some classes at The Crucible in Oakland and visit old friends.

~KMarsh