I got a paycheck this week and want to splurge. Should I get lego, clothing, or food?

As a white, affluent, non-disabled, hetero-normative male with a steady family life and good university education, I have little to complain about except my own stupidity.

As part of the freshman engineering experience at Northwestern University, teams of 4 or 5 students are assigned problems to solve, commissioned by various clients in the Chicagoland area. Last quarter, my team was addressing the need for a sleek, more lightweight rollator for the elderly. And we chose to make it out of carbon fiber (well, parts of it at least). Here is more or less the process for making a flat Carbon Fiber Reinforced Plastic/Polymer (CFRP) panel. For making curved shapes, you need a curved mold (and negative mold) to squeeze the layers of fiber and epoxy. Without further ado:

Materials Necessary

1. 24 sq. feet, roughly, of plain-weave carbon fiber sheets. Tow size is not direly important, but we used 24k with a loose weave. Each ply was quite thick and heavy. 2 Two flat 2x3’ polypropylene sheets (can be reused for each panel).
2. Very Sharp scissors or rolling cutter capable of cutting carbon fibers.
3. Ample amounts of West System 105 Resin and 206 or 209 Hardener. This is available on McMaster-Carr.
4. Paper towel, disposable cups, Popsicle sticks, and latex gloves.

Preparation

To prepare for the relatively fast-moving resin process, a fair amount of preparation must be made. Remember to wear gloves for this entire process—the resin/epoxy mix is a skin irritant.

1. Lay down one of your polypropylene sheets. This will be the “mold” you will lay the plies on.
2. Surround the edges with paper towel. This is a messy process, and the resin sticks to everything.
3. Cut your carbon fiber fabric into rectangles of approximate size 2x3’ and set them to the size in a clean area. Frayed edges are fine, as they will be cut off later. Remember, you should have plies ready at 90° and 45° weaves.
4. Make sure your polypropylene sheet is clear of all debris, then spray on a single layer of mold release agent such as SLIDE brand EpoXease.

Mold Process

1. Mix West System Resin 105 and Hardener 206 in a 5:1 ratio in a small cup. If using the West System minipump system, 3 or 4 from each is appropriate (as each pump is already in the 5:1 proportion). Now the clock is ticking, with your resin/hardener mix’ potlife of 15-20 minutes.
2. Stir the contents of the cup and try to work out any medium or large bubbles. Then, Pour most of the contents of your resin mixture around the polypropylene sheet, and use the wide side of a Popsicle stick to spread it around evenly.
3. Pick up one ply and lay it down evenly such that it covers the polypropylene sheet. Press down and check for any air pockets or uneven patches between the fabric and the mold. Press down with your hands so that the weaves absorb the resin on the polypropylene sheet.
4. Mix another 3 or 4 pumps of resin/hardener mix and pour this over the sheet. Spread evenly as best you can with your hands and Popsicle sticks, taking care not to distort the fibers. This is subjective, but try to assure that the entire rectangle is “wetted” fully with the mixture. If in doubt, add a little bit more, press, spread, and move forward.
5. Repeat steps 3 through 5 until all plies are used, making sure to use the 90-45-45-90 layering technique. If necessary, plies can be cut and patchworked together—just do not allow for overlapping. This is best done in the middle layers. Work as fast as possible, but the “working time” for the resin mix is around 50 minutes, so quite ample.
6. Once you’ve reached the top layer, add another pump or two of resin/hardener mixture and spread evenly. Check for bubbles or “dry” patches.
7. (Optional) Once fully wet, lay your second polypropylene sheet on top of the carbon fiber sheets. You may leave small weights on top if you desire to adjust thickness. This will ensure smooth surfaces on both sides of the panel.
8. Wait 24 or more hours without touching the panel for the resin to set. After this, carefully unstick the now-rigid mass from the polypropylene sheet(s)—it should be easy due to the EpoXease spray.

Tip for clean-up: use a razor blade to scrape runoff resin from the polypropylene sheets before reusing them to ensure maximum smoothness.

To cut the finished panel, we suggest using a water cutter if you have access, but a bandsaw (followed by some edge filing) works well too.

And for the record, this youtube video is pretty darn good at explaining the whole thing.

It’s now been a few days since I returned from Morocco, but I have some observations to share (à la Nick Gray). I spent a week in the country with my mother—Two days in Fès, about one and a half days in Marrakech, a day and a half doing on a “desert expedition,” and a day in Casablanca. It was a quick trip and included lots of transit, but I am happy with that, and my mom is as well—she is a Geographer and likes few things more than just observing landscape.

For reference, at the moment, $1 USD ~ 8 DH (Dirhams).

Some notes:

1. The country feels very european—that’s the French influence talking. Few things convey this better to me than seeing lots of roundabouts in the road system!

2. Yet, it is still a “developing” country. There are some problems that need addressing: namely, the absolute lack of a job market for college-educated people and the amounts of trash everywhere.

3. Large, old doors have two knockers. One for one family in the house, the other for a different family. They have slightly different sounds, and people learn to recognize them.

4. A riad is a “guest house” with a garden in the middle. A der is a “guest house” without a garden inside—just a fountain.

5. In general, a riad/der is an old-style house with an interior, open-air courtyard with surrounding rooms. They’re very consistent: marble floors, tile ornamentation (often with intricate zellij patterns), plaster walls, and wooden ceilings. This makes for good heat management in the hot months and cold, just by opening more or fewer windows/doors.

6. Fès is famous for its tanneries (smelly!) and its carpets. The carpets have two sides: one thick and wooly, for winter, the other tighter and more flat, for summer months.

7. “Petit Taxis.” Everywhere. Very noticeable by their red color. Taxis are REALLY cheap. A 20-minute ride cost us 16DH—$2. I’d suggest wearing a seatbelt, but you will really stick out as a tourist if you do so.

8. Also, this is where all of the old Mercedes 1900 and 2400s in the world are. They’re now “Grand Taxis.”

9. Fès has a nice amount of tourist infrastructure: enough so to enjoy the sights and be comfortable, but not enough to feel hassled by the locals. Marrakech, not so much; upon leaving I felt quite “milked” by the local economy for every penny in my pocket. Hustlers everywhere!

10. Casablanca, on the other hand, is a modern, slightly gritty, working city. No hustlers. Some big construction projects—private and infrastructure in nature—are going on, so I look forward to see it develop in recent years. There’s an imitation Rick’s Café there!

11. I’d never been to any Islamic-dominant country, and the difference when church and state are intertwined was noticeable. Hard to say how, but noticeable. The current king—Mohammad VI—is quite well-liked and is doing well. You’ll see his portrait around a lot.

12. Don’t walk on the sidewalk. The sidewalk is for storefronts and donkeys! And tourists!

13. People are friendly, but, as I said (especially in Marrakech), eager to sell. Everybody knows French and Arabic (both my mother and I have a working knowledge of French that helped us get around), and many know English or basic english too.

14. You have to pay for bathrooms. Well, not really, but otherwise the woman standing at the door will give you a nasty glare. They only ask for 1 or 2 DH usually. I only had to use a squat toilet once and most toilets allowed you to flush the toilet paper (!).

15. “We invented the siesta” — Our tour guide, Ahmed, in Marrakech

16. While less conservative than I expected, a woman’s life in Morocco is intensely private. “Men’s” trades, like tanning, metalworking, tailoring, etc. are done in public spaces or work cubbies in the souks (markets). “Women’s” trades, like carpet-weaving and basket-making, are done in their homes. It’s very rare to see women eating in restaurants.

17. Lots of restoration going underway, all the time. Large parts of Fès and Marrakech are UNESCO World Heritage Sites, and they take their ancient pride seriously.

18. The Medina of a city, or the “old city,” is made up of the kasbah (walled city), the mellah (typical jewish quarter), and the souks (markets).

19. Esp. in Marrakech, there are unregulated motorized scooters EVERYWHERE. Watch yourself as they come flying through the tight spaces.

20. Cats are everywhere and very tolerated. I took around 400 photos on the whole trip—45 of which were just of cats. Hanging around, taking care of pests. They even walk around nicer restaurants.

21. If you visit Marrakech, go to Jemaa el-Fna. Perhaps the most tourist-ey place possible, but it’s quite a spectacle. Let yourself get wrassled into a stall by the shouting men, and enjoy the cheap and good food.

22. That said, FOOD. Expect olives and bread with every meal. A “Tajine” is a typical conical dish, used to cook and serve any kinds of meat or couscous dishes. Food is good. Food is cheap. Eat lots.

23. More notable in Casablanca—quite a bit of ethnic variation.

24. Camels are really uncomfortable to ride (especially as someone with male parts). That said, they’re also quite fun to ride, sound like Chewbacca (or maybe that’s vice-versa), and feel like a roller coaster when they stand up or sit down!

25. Schooling is optional for kids. Lots running around at all hours of the day.

26. You’ll hear calls to prayer broadcaster via loudspeaker 5 times a day. Actually a very good wake-up call!

27. There’s a level of local artisanship in the country that simply isn’t found in the U.S.A.. In the souks there are tailors, blacksmiths, tanners, tinsmiths, farmers, dye-makers, and more, simply doing their “artisinal” work, because it’s their work. I don’t quite have the words for how different this is from the industrial, business-driven world here (versus the individuals’ work there).

That’s about that.

I think I like math and art for the same reason. They’re both efforts to express ideas in basic elements—colors and forms for art, symbols and numbers for math.

Landed an internship in NYC for most of the summer!

Hopefully I’ll kick around Chicago long enough to attend Brickworld first though—dates aren’t quite set yet. Maybe some time at home with my own lego and video games too…

I’ll be making math models to explain growth in developing countries. I’m thrilled.