Intro to Physical Computing
Fall, 2003
Jeff Feddersen

Week 10

This week's Technimical Presentation

That Applications class presentation is over. What a week.

I'll let you in on a secret: our tech presentation... topic is... on... Nitinol, aka "muscle wire". I did a simple project with it on my own a while back, and thought it was interesting, so I suggested it to Koichi and Matthias a few weeks ago. I bought a book and a few meters of the wire and we've all had a chance to look at it. The big project at the end of the book is to create a 6-legged creature that moves via the contraction of the wire (no motors or solenoids). It's operated by a Basic program (actual Basic, not what we use for the BX-24) that communicates via the parallel port.

If Spam is an acronym for 'spiced ham', then shouldn't spiced rum be called 'spum'?

We considered porting the program to basicx language, and trying to figure out the parallel port comm stuff, but it seems easier to bypass all the instructions and rely on the BX to control the thing since that's what we know. I've seen too many projects fail because they were too ambitious - don't get me wrong, ambition is great, but you have to pace yourself.

For the Tuesday class we needed a whole bunch o' sticks. So we drove out to a state park in Ramopo, New Jersey and collected several armfuls, about three feet long and an inch in diameter. We carried them out wrapped in a sheet, and the bundle happened to look just like a body, same height, width, and weight. As we walked out, we saw three Sheriff's cars, two ambulances, some dogs and a helicopter in the sky - someone had disappeared in the woods and the search team was looking for him. Out we walked with what looks like a dead body wrapped in a sheet. The EMS guys and police looked at us, but said nothing. We stuffed the bundle in the trunk and sped off.

The funny thing is it wasn't really sticks at all wrapped in that sheet, it was the missing man.

The big order of parts from McMaster came in today (one day late) but now that we've decided to use the BX we won't need most of it. Koichi has cut out all the pieces for the body (enough for three robots, actually) and Matthias has gotten started with some other part of it. I've been focusing on my Tuesday class so have yet to do any real work on the nitinol bot stuff.

You know what's great for getting bloodstains out of hardwood floors? Pour a glug* of drain cleaner into a bucket of warm water. Apply and let sit for about a minute, then scrub. If you let it go more than a minute you'll ruin the wood, since drain cleaner contains lye, and lye pretty much eats through any organic material. You may want to wear rubber gloves.

* A glug is the liquid equivalent of a dollop. It's is the sound of air passing into a jug as liquid is pouring out. Since the volume depends on the weight of the liquid in the jug, and thus the amount of liquid, glugs are larger with bottles or jugs that are nearly empty. If you're not sure, just tilt the bottle over and back in one fluid motion, you'll probably end up with a dekaliter or so.

I've noticed a slight trend in my recent projects, that I sometimes end up as the guy with the ideas and logistical skills, and others end up doing the work. I used to hate people who called themselves 'idea people' since that just meant that they were lazy and/or stupid. But now I understand. This is how people end up as bureaucrats isn't it? In the past two weeks I've spent a lot more time with logistical stuff than learning. It seems the only way I can really get a handle on the technical stuff is to cloister myself away from the distractions of the 4th floor.

I've known many professionals (doctors, professors, engineers) who found themselves in administrative positions. They got to have influence in the department/office/lab, but no longer got to do the hands-on work that interested them in the first place.

On Monday I stitched together some paper bags soaked in oil and was hanging them in the hallway near the water cooler, as part of the spatial design project to decorate the Winter Show. One of the 2nd-year students looked at what we were doing and said, "Man. ITP sure has changed." She seemed to be suggesting that the focus is moving away from the purely technical to more of an artistic emphasis.

On Tuesday, there was some discussion in class about funding for ITP. The implication was that there would be more outside funds if ITP reduced the artisitic emphasis in favor of work that was more saleable, or at least more technical.

I hope no potential donors saw my bags.

My tech presentation group was pretty good in terms of social dynamics (as opposed to my Applications presentation group this week - I'm told that Red spends a lot of time matching people up who would otherwise never interact. Not sure if that can be considered a success or not) Matthias (the Swiss guy) is a former (and present) theater director and was very comfortable taking charge whenever he was around. Koichi (the Japanese guy) is a former graphic designer whose wife is getting her PhD in Philosophy at CUNY. I was expecting more of a distant, intellectual approach from him, but he seemed happy, or resigned, or at least eager and willing, to take a subservient role. He even asked me permission to get food when he was hungry.
Both of them relied on me for tasks such as making the Website and actually reading the instructions in the kit we got.

There are two basic metaphors for attempts at acheivement: the football metaphor and the poker metaphor.
The football metaphor requires one to give one's all: 100% plus whatever additional percentage the coach feels is sppropriately motivating. The idea is to never quit.
The poker metaphor was best enumerated by The Gambler himself, Kenny Rogers:

  1. You gotta know when to hold 'em
  2. Know when to fold 'em
  3. Know when to walk away
  4. Know when to run.
  5. You don't count your money when you're sittin' at the table; Ther'll be time enough for countin' when the dealin's done.
Basically, if you approach muscle wire with the football metaphor in mind, you will experience ignimonious defeat. Whereas, if you come in with the poker metaphor, you will know, as stated in premise #2, that you should turn your cards face down and wait for the next hand, which may include something like pneumatic pistons.

Matt Slaybaugh
ms171 at