Sunday, October 13, 2013

A Better Zombie Bunker

To kick off Season 4 of The Walking Dead, I decided to do a little engineering exercise to design a better zombie "bunker". 

- Doesn't require occupants to remain quiet.
- Continuously destroys zombies without using extra resources or labor.
- Easier to manufacture than underground bunkers.
- Scaleable: greenhouse or extra living quarters can be installed adjacent to preceding structures.
- Occupants do not suffer psychological effects of living underground.
- If lights are kept on, the bunker continues to dispose of zombies after occupants pass away or leave.
- Bodies cannot pile up around the structure as with a traditional fortified structure.
- Sanitary: occupant waste can be dumped directly into river below.
- Spacious: extra ceiling height is not as expensive as with an underground bunker.

- Still requires heavy machinery to install.
- Occupants hear the constant moans of zombies outside.
- Still requires greenhouse and/or outside source for food.
- Fresh water must be pumped or lifted from upriver.
- Difficult to install with zombies present.
- Possible harmonic oscillation in high winds.
- Becomes less effective at zombie disposal after all light bulbs burn out.

Additional ideas:
- Add windmill, wind chimes, or other wind-activated devices to attract zombies after lights burn out.
- Add skylights and 2-way mirrors so that occupants don't have to see zombies, but still get sunlight.
- Zipline?

What do you think?

Sunday, June 2, 2013

Contour HD Gen1 Review

In October 2011, I participated in the first Run For Your Lives event, a 5k in which the runners are chased by zombies. Since it was the first one, I wanted to film it for this blog, and I decided to get a sports camcorder to wear while I ran. There were only two notable sports camcorders available at the time: the GoPro and the Contour HD. I chose the first generation Contour HD over the GoPro because the Contour had a simple switch on the top of it to start recording. It also sits on the side of your head instead of on the front. Here is a summary of my experience with the Contour HD:

Battery Cover:

The company claims that the camera is mud-proof. Under extremely gentle conditions, it is. The biggest problem is the design of the battery cover. It's a rubberized piece of plastic that slides over the battery/USB port/microSD slot to keep mud out. Unfortunately, there is no seal on this piece and it will let water in with just a light rain. It snaps on and off(there's no latch or button to secure it), so if the cover is bumped against anything, it will come off. To be fair, although the camera has let water in, the water did not cause any problems with the circuitry. The company recommends their waterproof housing if you want to submerge the camera.


The sliding REC switch on top of the camera was Contour's most marketed feature. It's a good idea, because unlike a button, you can feel the position of a switch without taking the camera off of your head. However, the switch has very shallow stippling and the other surfaces of the camera are completely smooth. For the switch to be secured in either position, they made it really stiff. This make it really difficult to turn on the camera with gloves or with mud on the camera. To make matters worse, if you put any pressure on the battery cover when sliding the switch to the "off" position, the battery cover comes off. Seriously that battery cover is a POS design.


The Contour HD comes with two lasers attached to the rotating lens assembly. When activated, these allow you to rotate the head to make the camera level, as well as point it in the right direction. These do help a lot, since the headband(separate product) tends to point the camera towards the sky. The lasers are just arbitrarily positioned toward the middle of the frame, so you get no sense of what is in frame or out of frame. Still, it's better than GoPro's method of guess-and-check. I think some newer Contour cameras let you stream to a smartphone to aid in framing.


There's only one button on the outside of the camera. Hold to power on(sounds one beep), hold to power off(sounds two beeps). Press once while powered on to activate the lasers for ~15 seconds. There is a green light on the front of the camera that you can see out of the corner of your eye, so you know when the camera is on and ready to record. This light turns orange once the camera starts recording. If you take off the battery cover, you will find a small switch that allows you to choose between two recording settings(you set these in the software). That's all you really need. I actually really like the interface.

The included software is required to adjust the recording settings for the camera. You can choose video resolution, shutter speed, and lighting options. The camera doesn't come with a wall charger, so you have to use the USB port on your computer to charge the battery. Unfortunately, plugging the camera into your computer automatically launches the Contour Storyteller software. It's annoying, but you can turn it off in Preferences. Another annoying aspect of the software is that it requires you to create an online account. You have to create the account before it will let you adjust the settings on your camera. Why is this even a thing? It's just stupid.

Would I recommend this camera to a friend? No. Not until they fix the idiotic battery cover. And it really wouldn't take much effort for them to make it waterproof. Seeing how quickly digital cameras are evolving, I'm sure these sports cameras will be exponentially smaller and lighter in the next few years.

Saturday, April 27, 2013

The Ice King's Crown

My friends and I are big Adventure Time fans so I decided to make a prop from the show IRL. I made this back in February as a belated Christmas gift for my crazy Asian friend who bites people. Sorry I was in a rush to make this one so I don't have any in-progress photos.

Ice King (a.k.a. Simon Petrikov)
It's my take on the Ice King's crown. For the "gold" part, I first tried gluing plastic paint buckets together, but they were too thin. I ended up covering the outside of one bucket in Bondo and then cutting in the peaks with a jeweler's saw. For the jewels, I cut a positive mold for each one out of a scrap of cutting board, then pressed them into clay to make a negative mold. Then I mixed up some casting resin and red dye and cast the jewels. They were epoxied onto the crown before I locked them in with Bondo bezels.

If I were to do it again, I would use a more acute conic shape and make the peaks taller. I might also use fiberglass-reinforced Bondo and try a different gold paint. If I'm real adventurous I'll cast the thing out of scrap aluminum.

I've got some RepRap projects and another prop build in mind so stay tuned.

Sunday, March 3, 2013

The Biggest Selling Point at the 2013 Washington Auto Show

Me and some foreign kid went to the 2013 Washington Auto Show in D.C. a few weeks back. Honestly, there wasn't anything spectacular...until we opened up the hood on the new Scion FR-S! There it was, sitting right on top of the engine: the oil filter!

Photo: Samin Emini

If you've ever changed the oil in a car, you'll appreciate the gift that Subaru has given FR-S owners. Oil filters are greasy, elusive, and tend to tighten themselves to a torque that no human can defeat. And on almost any other modern car, the oil filter is on the bottom of the engine mounted at an inexplicable angle with a skid panel or other parts obscuring its access. When you do finally manage to get it off, the residual oil sitting above the filter drains out all over your hands. The FR-S does you a huge favor by having the oil filter right there, right in front of you for easy access. Additionally, since it's on top, most of the residual oil will drain from it when the oil pan is drained. That way you don't get oil all over the garage floor. The only other time I've seen an oil filter this accessible was on an industrial diesel generator like this one:

On top of all that, they went with the classic form factor instead of Toyota's new plastic shell shit. I was pissed when I had to change the oil on a new Camry and discovered the new filters they're using. Instead of a metal, single piece filter, they chose a plastic shell with plastic threads that requires a special filter insert, and two different o-rings. It's okay to damage a metal oil filter because it's a consumable part, but if you break a plastic shell filter, you're dead in the water. Oh and it costs more. Who's bright idea was this?
Anyway the FR-S has other neat features such as rear seats that are extremely comfortable if you have no legs or head.

Also on display were some of the military's unmanned equipment, including some awesome shit from Boston Dynamics. Seriously if you haven't seen these before, take a look. They're nuts. First up was the RHex Rough-Terrain Robot:

The RHex just looks ridiculous when it's going full speed. I love it.
Next is another one of my favorites, the Sand Flea. That black rubber bumper is actually the foot of a piston that launches the robot over walls and up flights of stairs. It's one of those "Why didn't I think of that?" designs.

They also had a couple standard ROV platforms and a remote-operated mine-clearing skid-steer loader. Wow that's a lot of hyphens.

And last we have a deployable solar power station. I would love to design stuff like this for a living.

Tuesday, December 18, 2012

How To: Classic Toy Car

Instructions in white.
Commentary in blue.

This project was inspired by MAKE Magazine's Fast Toy Wood Car article. Make's car uses layers of laser-cut plywood to form the body of their car. I liked the idea but wanted something more durable, something that would last generations of abuse, or at least a few hand-me-downs. My solution is to shape the car from a single block of wood.

Price: ~$20/car, cheaper if making multiple cars
Difficulty: Pinewood Derby
Time: 30-60 minutes/car, depending on tools used

Step 1: Tools/Materials
-band saw/jig saw/coping saw
-miter saw/hand saw

Monday, November 12, 2012

In Pursuit of Human Flight

Last Friday, I drove up to Maryland to see UMD's Gamera II human-powered quadrotor. They are currently pursuing the Sikorsky Prize, established in 1980. Here's the team testing a new control system:

During this test, Gamera II flew for approximately 65 seconds, unofficially tying the endurance record that the team previously set. This flight time, plus the ability to remain within a specific boundary, satisfies two requirements of the Sikorsky Prize. Because the rotors are so close to the ground, the helicopter is benefiting from a cushioning effect of the air between the rotor blades and the ground. This effect will diminish exponentially when the team attempts sustained flight at the required 3 meters.

The helicopter transfers the pilot's pedal power by unspooling cable from pulleys, mounted on the shafts of each of the four rotors. Flight time is limited by the pilot's stamina and the amount of cable stored in each pulley.

The rotors are constructed of carbon fiber, balsa, and foam, and are covered in a plastic film.

All in all, it was a cool experience. I've never seen so much carbon fiber in my life! I look forward to seeing the team win the Prize.