Phone Case Versions 1-3

Last winter, I designed a phone case for fun. When I designed it, I envisioned it out of aluminum. This idea was quickly scrapped as I thought about the effects on signal strength and how it was very easy to 'hold the iPhone 4 wrong,' according to Steve Jobs. In the summer of 2012, BU got a MakerBot Replicator and I decided to give my design a shot. 

Original.

There happened to be black plastic in the machine, so the case was black. It was a pretty good first try. The major things I didn't like about it were how flimsy it was, and how it didn't hold on to the phone as well as I wanted. It could be pushed side to side over the grooves on the iPhone 4 very easily. Additionally, the buttons were a bit tough to reach, despite the little recessions in the case.

At the time of the pictures, I didn't have any 1/2" 4-40 screws on hand, so this is the best I have. The screws were filed down and a hex nut was put on the back to hold it in place. This idea was scrapped because the nuts kept falling off and also placed unnecessary strain on the very thin corners of the first iteration of the case.

The next iteration came in late November. I had been using the first version for about a month after my 'real' case bit the dust. Props to Speck though, that case lasted me a year and a half. This second version had several modifications. The first was that the buttons were SUPER easy to reach, and the second was that everything was thicker. I did print one back piece with hexagonal cutouts for nuts just to entertain the idea again, but it felt forced and didn't look that great, given that I wanted to keep the case as compact as possible.

 This time the plastic in the machine was not black, but red!

After using the case for a few weeks and completing finals for fall 2012, I realized that I hadn't got any gifts for most of my friends for their respective winter holidays. Like any clever, financially broke engineer, I printed them iPhone cases with a little bit of personalization to make it seem like I put some effort into their gifts. (Boy, did I fool them...) Unfortunately, several weeks later one of them reported a four foot drop onto a tile bathroom floor which spawned a crack in the top. This quickly propagated inward and the upper left joint came loose. Just today, the other friend sent me a picture of his mutilated phone case, which had suffered similar failures. I'll take this time to say that my 'V2' case is perfectly fine and has survived several drops, albeit not onto tile floors. 

Tile floor: 1
  Case V2: 0

Bear attack.

Regardless, this motivated me to design version 3, which made the top piece significantly thicker and changed the structure of the side on the front only. The left side now appears to be whole from the front, but has a chunk cut out so that fingers can easily reach buttons from the back without sacrificing structural integrity.

So there you have it. We'll see how this iteration fares in the real world and I'll update the post with changes. Side note: several people have suggested that I try to mill this out of a stronger material, such as polycarbonate. This sounds like a good idea and wouldn't be too difficult to do in theory. This might happen. Hmmm.

Noble Six Helmet

Wow, it's been a really long time since I've updated this, mostly because I've been busy recovering from an appendectomy and pretending to be musical. A few posts ago, I mentioned that I was making something for a friend's birthday. That thing was my short-lived adventure into the world of prop making. Basing my designs off of those from 405th.com, I created laser cuttable files for Noble Six's helmet, from Bungie's Halo: Reach. I replicate the pepakura build in AutoCAD and cut the shapes out of 110 lb cardstock. The designs ended up on 11 sheets of the stuff, and took about two hours to cut, including setup. I still have most of the ream of cardstock. As a joke, I printed an essay on it, but have found no other use for it.

Guided by the original files in Pepakura Designer, I made a few of the major pieces, and then gradually glued them all together. 

Note to those thinking about doing this: hot glue is strongly advised because of the quick set time and the ability to heat it up again if you make a mistake. Keep plenty of glue on hand (I went through about a dozen of the small sticks in the process) and give your glue gun a break every so often - the handle on mine got pretty hot after a while.

Next in the process was the fiberglass and bondo. I used fiberglass mat and resin on the inside for structural integrity (bonus: itchy fingers) and bondo on the outside to smooth out the fairly wrinkly paper, add some bulk where needed, and hide errors.

Fiberglass. Note to self: use cloth next time; mat sucks.

I just realized that I don't have a picture of the helmet after I sanded down the whole thing. Oops. Anyway, the next step was painting the thing. The order of coats are 2X black matte, 2X silver, 2X blue, and finally black on the back and the visor perimeter. Painters tape was used to section off different areas that didn't need to be painted after a certain point, such as the visor. Vaseline was applied in 'swaths' to imitate scratches from battle.

Second coat of black. Nice and thick... and drippy.

First coat of silver.......... right.

2X silver.

Blue (as per Ben's character in the game)

It's a lion.

"Done."

Bonus ALVIN.

So at this point you're probably thinking something along the lines of, 'That came out pretty well for his first shot at making a prop from a video game, but how the heck is he supposed to see out of the darn thing?'

I was thinking that too; I'm glad we're on the same page.

At The Saturday Thing sometime in the fall of 2012, I got around to trying to make a visor for the helmet. This was supposed to just be practice, but I sorta decided it wasn't worth the effort to do it again. I started out by cutting out the silver chunk and making a frame/jig that I would use to press the acrylic piece into place. I used a heat gun and a large PVC pipe to make a rough bend in the acrylic, pressed it into place with the jig, and glued it into place. Not perfect, but it'll do.

The visor-hole and rough cut/bend of the acrylic piece.

This took a long time.

"So thats our new number Six?"

So there you have it. I have another blank helmet in my garage that I built on a whim, thinking I would have the time to make another helmet. I may try to do something with it, or it may just sit indefinitely.

 I have a few more posts coming soon, mainly something about a phone case and some really tiny things. Happy reading!

MRT Alaska Trip - August 2012

After mentoring in the Engineering Design Workshop each day, I worked with the MIT Marine Robotics Team to prepare for a testing trip in Alaska. Over the course of June and July we prepared two gliders for testing in a pool and in open water. One of the gliders was about two and a half feet long and served as a proof-of-concept model and experimental platform for sensors such as GPS, pressure, and dive/rise indicators.

Tommy and Baby glider

The second glider was our main focus. At five feet long and 60 lbs operating weight (about 45 lbs without ballast), it was tons of fun to bring through TSA... twice. After an hour long private security scan and half a day of travel, everything and everyone made it to Ketchikan safely.

Bubble wrap + greenie

The people at Ketchikan Gateway Borough very kindly let us use their dive pool for testing almost every day during the trip. It was an excellent place to test because the pool was nearly empty at 8am and we could easily trim the glider, check for leaks, test sensors, and get great footage from a GoPro mounted on Tom's ROV at the same time.

And they had a slide two slides.

The team also helped with a program called SeaGlide, which introduced middle school students to the world of underwater vehicles and showed them how to make mini-gliders using water bottles and an arduino. The program was spearheaded by Robert Vieth who specializes in STEM outreach in Alaska. Several employees from the Carderock division of NAVSEA also helped with the program.

Cleaning up a few of the 3D printed parts with our fancy knives

We also toured SEAFAC, but weren't allowed to take pictures most of the time, probably for a good reason. The best I could do for photos were a few on the boat ride out and one in their machine shop.

Biggest lathe I've ever seen

Lastly, the highlight of the trip happened after we had been given a tour of the mariculture facility and were allowed to test our large glider after showing it to the kids in the SeaGlide program. Gary Freitag was kind enough to let us use his SeaBotix ROV to get footage of the glider in the ocean. It also had a manipulator arm that we could use to grab the glider in case the glider decided it didn't want to come back up. That didn't happen, but the first untethered run was pretty terrifying/awesome anyway.

And so we put the buoyancy engine on a timer, dropped the glider in the ocean, and waited. David was in a kayak and I was piloting the ROV and everyone else was useless. Just kidding, they helped feed the tether off of the 800' spool. 

Warning: the awesomeness of the story that follows is not accurately portrayed over the internet. I'm not even going to try.

- Glider put in water

- Glider floats, refuses to sink despite pleas of MRT

- Two washers zip tied to back of glider

- Glider is pretty darn close to perfectly trimmed

- Glider starts dive cycle

- Dive looks good

- People start to remember that there is no tether

- Excitement ensues

- David is alone outside because everyone is inside looking at the ROV screen

- 20' below surface

- 30' below surface - we reached our target depth for the trip!

- Glider still diving

- People start to freak out

- Tom tells Adrian, "DON'T LOSE THE GLIDER. STAY WITH IT"

- Adrian stays with the glider

- 43' below surface

- GLIDER STARTS TO PULL OUT OF DIVE

- GLIDER COMES BACK UP TO THE SURFACE

- EVERYONE IS GOING CRAZY

- WE DID IT! WE DID IT!

- WOOOOOOOOOO

A video of our most glorious moment, accompanied by appropriate music follows. A few notes: the FS at the bottom stands for Feet Seawater, and the CA stands for Camera Angle. This is how we got our depth reading for the glider.

After we pulled the glider out, we got to have some fun with the ROV. Ed ended up stabbing picking up a sea cucumber from 200' and brought it up. When it got to the surface, it was a bit floppy from the pressure change, but fortunately it didn't evacuate its bowels on us, as sea cucumbers are known to do.

warp speed

"It's what's for dinner"

After returning the sea cucumber to its home and packing up, we merrily feasted on land animals, as seen in the following picture.

Kodak moment

Engineering Design Workshop 2012

In July of 2012, The Edgerton Center hosted the annual Engineering Design Workshop. The program brings in high school students from around the world to work in teams on a project of their choice. This year the program had 24 kids and 6 mentors, which turned out to be a pretty good ratio. In addition to the mentors, the workshop had Ed Moriarty and John McGoldrick as general overseers and sources of infinite wisdom.

Ed talking with the kids on the first day

 My group decided to make an autonomous vehicle with the final goal of having it deliver caffeinated beverages to Ed. This goal was never completely achieved, but the wall-avoiding robot we ended up with worked well and everyone involved gained valuable experience.

A few photos along the way:

Yashasvi sitting on David's group's project

People doing things with stuff

Ed skyping in from Alaska for design review and updates

JDOB/UAF/ASRA says hi!

John the shop safety specialist

my first steering assembly

Rolling chassis

Intermediate step: RC vehicle

After staring at the vehicle for a few hours we discovered that unnamed student
had used digital pins when he should have used analog pins

Making the vehicle 'safer'

Battleship group

Single-fan hovercraft group

Batmobile group and the resulting tricycle

Dual-fan hovercraft group

Autonomous vehicle group

And so another Engineering Design Workshop came to a close and some of us went back to a normal sleep schedule and some did not. At the same time as the workshop, three of the six mentors (Jackie, David, and myself) were also preparing to test an underwater glider in Alaska and left for testing the day after the workshop ended. I'll post about that in a few days when I sort through the thousands of photos and videos that were taken on the trip. In the meantime, here's a preview:

$50,000 ROV catches dinner