Friday, February 22, 2008

Stage Hands

Assembling the motion section and adjusting the elements so they fit.

I love that time when you have to finally begin working on the stage for a play. It means the performance is imminent (unless the producer pulls out!). It is also time to listen carefully to the director, designer, performers, lighting and sound people and stage hands and riggers to make sure all points of view are represented and taken into consideration. (if only it was like that in real life...)

Since the hole pattern in the VeX system is not really well designed (unless someone proves the contrary) I had to notch and cut lots of pieces so that they overlapped correctly in the configuration I needed. As I said before, I think the engineer/s who designed the system probably did it with a preset number of projects in their mind.

I would go back to the drawing board. It seems strange to me that in this age of CAD and relational tools, they could not test at least a few thousand combinations and optimize the design for that. So anyway, the metal is soft enough that it doesn't take that long to adjust.

The Vex control modules, servos and power supply.

Except for Lorena, who is the human performer, choreographer and costume designer for the project and who makes sure her needs and demands are met:-), the rest of the crew is me with occasional help from my friends, like Philip who is working on a Flash interface to control the microprocessors and sensors. I have my doubts about the speed of the image processing functions in the new Flash, but it is worth a try.

For now I am using VeX to build the stage support and to prototype the motion and control system. Ideally I would like to use a faster microprocessor, perhaps Propeller by Parallax which is a multi processor where each one of the 8 processors can operate simultaneously giving you the ability to respond in real time to performer actions, which is what I need to do.

Easier said than done, since programming is not my forte, but my friend Philip, who is in his final year in Architecture, loves coding and we have done great work together. I need to complete the prototype so that we can start programming and optimizing. Everything simpler, easier, faster. Like Ars Electronica 2006 theme said, SIMPLICITY - the art of complexity.

The Creator's new feet

I am also getting so much more familiar with the marionette I've created, since while you are whittling away at blocks of wood and dealing with joints, balance and many other issues, it is difficult to meet the creature on its own terms. Although it is not awake yet I can already see a bit of its character. This is an experience which every puppeteer, or for that matter any artist goes through as it transitions from production to contemplation or analysis and finally to understanding or appreciation.

This process is not so familiar to the engineering folks, since for them, in the majority of cases, everything must be defined or though in toto in advance and there is usually little room for improvisation

Monday, February 18, 2008

Gimme Shelter

Time to create the scaffolding for the Creator's shelter. It will hopefully be as functional and form(ally) beautiful as it can be. In trying to find the right tools and materials I bought some Vex kits when Radio Shack decided to chuck them. So in a way I got a good deal. From a tinkerer's perspective though I wish I had my (very) old Meccano, which from an engineering point of view was a lot more versatile I believe.

The problem with the Vex "system" is that it is not really integrated. It seems to have been designed, not as an optimal modular construction set, but rather limited to some preconceived ideas as to what you should do with it rather than let you decide, as the Meccano system allowed.

I find it very limiting for free form design. Take this example. To construct the very simple structure I needed required me to use ALL 5 kits! and I am not even close to be done.

When you think of which is the most useful and common structural element in construction, I am sure that the majority of "architects" or engineers would agree that it is the humble angle, strong, simple and functional. Well, guess what, the entire Vex kit comes with a whooping 3 angles! yes, that is 1,2,3! But what were they thinking?

This forced me to construct the main columns with rails (of which there are quite a few) which prevented me to attach the rest of the support elements in a simple way.

The kit does come with lots of elements that might have some use in some specific project but it is the least useful grouping of parts in any construction kit that I have found. There must be a reason behind this, and it is probably very sound, like ka-ching! Almost any project will require you to buy extra hardware, at a very steep price, and you can bet (and would win) that the "dedicated" hardware kits bring a completely unbalanced set of elements as well, so that you do keep on buying. Bear in mind that I am not building anything exotic as you can see from the pics.

The structure is 80 cm. tall and 33cm wide, making it a harmonic rectangle area. Of course it is not exact, since it never occurred to the designers that anybody migh need , want or know about such things as harmonic proportions.

Wednesday, February 06, 2008

String Instrument


Here is the Creator waiting to have his nervous system installed. The secret to a balanced marionette lies mostly in the stringing that controls it both internally and externally.

The strings that hold the different parts of the body from the inside act as ligaments as well as nerves, that stabilize and enable the parts to move in relationship to each other. By transferring forces and movement information through the spinal string, which is the case with our body, it keeps us balanced and acts as a conduit through which our brain controls our movement.

In the case of a traditional marionette, that brain or intelligence comes from the learned hand of the player of the strings, the puppeteer.

In this case it will be the computer or rather the microprocessor, together with the sensorial system that feeds it information about its environment, that will make the equivalent of conscious decisions as to what to do and when.

The other part, the involuntary movements, the character, arise from the structure that has evolved from interacting with the laws and forces that constitute the semiotic "liquid" in which the creature evolves.

This evolution has produced the structural support (skeleton) and the relationship between the systems that allow both us and a marionette designed under those principles to act and respond accordingly, with or without consciousness or awareness of that which ultimately controls us.

This sequence was produced simply by lowering
the spinal control until it no longer supports the body.

Hip Gnosis

Do and learn. The hip and waist proved to be not only very heavy but also out of proportion. Looking back, this happened because I scaled the entire original schematic to simply make it taller without really thinking through the proportion of the individual body parts.

So, here I go again. I redesigned both hip and waist and decided to use pine wood instead cutting the overall weight considerably by almost 300 g. My servos will thank me!

Since I was going to start from a wood block this time, I was able to drill the holes in a more controlled fashion, sort of, because some of them traversed the block at extreme angles. But overall this fact alone made the parts fit better. Molding the parts with Apoxy was fun and quite easy and fast, but not the right solution in this case.

Here you can see the difference in size and weight, of the old and new hip-waist combo. Of course the scale change rippled through the entire puppet since I had to also modify the torso and the legs. I know I must do the same with the arms, which I am putting on hold for now because the wood is so amazingly hard. But it will happen.