Category: Creative

Robot eye tinkering

Not much tinkering today, but I grabbed a few pics.

This is the rotation section of the “head”. I suppose it would be the wrist if it were a grabber-arm. Little motor’s from the autofocus of an old camcorder, main gear is from a printer paper-feed. It already had a bore of 10mm so I pressed a couple of miniature bearings into it to provide ample support. It’s drilled to 8mm on the other side of the face-plate to the bearings are retained but so the M3 screw remains a static axle. The gear is mounted by drilling through three of the six handy injection-moulding marks on the gear, then tapping the plate. Finding screws that would fit in the recess was tricky.

Mind you it’s all tricky. It’s all built from junk I have knocking about. It’s just handy that human civilisation works on a few different standards and measurements, so if you have enough parts to throw at it sooner or later something will stick together. Trial and error’s what’s taking the longest here, rather than outright manufacture.

Another thing that took time was finally assesing a bunch of used servos I picked up ages ago. About half had broken gear teeth, so while I managed to put together about 5 working ones the rest are just partials unless cheap gearsets are still available for them. (some seem to have all-metal gearsets still available in old-stock form, but since I’m not really spending money on this..)

Actually I am spending a little money. About £20 on ebay for a PS3 Eye webcam for the vision and a couple of ultra-tiny servos from China (1.5g each!) to try and make some moving ears.

The small servo on the right there is one of those with a lot of broken gears. But it’s motor is about the same size as the autofocus motor, so I’m going to try and attatch the servo’s position-pot to that loose middle-sized gear. I’m eyeballing everything on this, but I think that will work and give the head about a 60-degree range of rotation from about 190 on the servo. It should be handy to be able to run it as a servo rather than directly.

How those servo parts attach will depend greatly on how I end up rigging the pan-tilt mechanism with some old Futaba FD30M’s (re-branded S20’s). Presuming they still work anyway; I still need to solder new wires to them and hook them up to the Arduino for testing. Mechanically they’re fine though and should be easy enough to connect to even without servo horns, due to the square spindle style.

That’s the plastic cowling that press-fits to the aluminium plate. I have no idea what it’s from, other than that I found it back when I lived in Hastings and it’s been knocking around my parts bins since. I think it may have come from a motorbike, as I did find some odd bits of faring down the main road at times. Else it came from the old stockroom skip at the factory, in which case there’s no clue at all. It’s a nice tapered shape and not too heavy, so will make a nice cowling here.

I cut up some old difuser plastic to see how the final thing might look. I’m thinking of surrounding the cam inside with a few RGB LEDs to convey things visually. I’d like to fit a speaker too, but nothing’s sprung up at me yet in an appealing way. Time will tell.

This is all evolving from this:

It’s a decade-old Logitec Quickcam with no casing attached to an angle-poise lamp (technically 2 , since I combined them to make a more heavy-duty angle-poise frame) via a block of wood. It’s worked quite nicely as a workshop webcam since it’s been pretty stable and allowed me to move the cam rapidly around, but the attachment leaves something to be desired because the image ends up tilted because of the order of axis. At very least it needed a new mounting arrangement which wouldn’t have been hard.. but running a computer-controlled arm into some machine-vision software with off-the-shelf face-tracking scripts to make a motion-tracking robot cameraman? THAT would be fun.

It may also let me toy around with enhanced and more intuitive computer avatar feedback for video-calls or general computer control. And avoid creepy computer avatars like Dreamer or Pintsize.

I might call it Max.

Tinkering..

I should be clearing up.

I should be doing exercises.

I should be learning more database theory, writing adverts, making moulds, doing accounts, doing innumerable small odd-jobs to get in a smidge of extra cash.

But I’m not.

I’ve indulged myself this last couple of days and it’s felt good. I’ve been tinkering in the workshop.

Long story short, I’ve been trying to motorise the angle-poise lamp I have the webcam attached to, with a view to getting it hooked up to some machine-vision software for motion-tracking and having it run as cameraman. At least it started there, and now I’m looking at adding microphones, a speaker and tri-colour LEDs to turn it into a sort of intuitive feedback device.

It’s essentially a robot arm though, with 6 degrees of freedom. I’ve never made a robot arm before. I also have no spare money to throw at it, so I’ve been running through my various parts bins.

Collecting “useful” things, and/or taking them apart to see how they’re assembled is something of a compulsion. However actually recombining them feels like something I’ve let atrophy. It’s been frustrating at points, but it’s an enjoyable indulgence. And it feels like it’s starting to get back into gear a bit.

It’s also helpfully letting me see what parts are actually still any use to me.

Sci, you were a massive dofus.

TLDR: Fun times with teenage 3rd-person rambling.

One of things I’ve been taking on this week is sifting and transcribing the huge pile of old notes I have kicking about. A foot-tall pile of scraps and scrawled-on envelopes.
Most of them are going to be compiled into more succinct lists of ideas, information and so forth. Then the original mess can be tidily burnt, and I can process anything useful out of the notes.

I’ve just finished transcribing this gem though which will be avoiding the burn pile for the time being. It’s a handy reminder of how far I’ve come, even if it does make excruciating reading.

The bit that bugs me the most is that as I started transcribing it I figured it was something I’d written early in high-school, maybe around 13-14 years of age. But no, I hit the point where it talks about being 17 in past-tense. I was 18 years old and wrote like this? How was I never tested for dyslexia?
Maybe that’s for the best anyway considering how I wore my existing faults as a badge of pride then.

Anyway here it is, original spelling and obsession with commas preserved.

Continue reading “Sci, you were a massive dofus.”

Writing: Disposable FTL premise

Some ad-hoc writing on the premise of a disposable FTL system.

The matte funnel-shaped device sat dead out in front of the ship while it’s backdrop of stars spun around and around. The ship was spinning up for jump gyro-stabilisation. Putting the spin on the ship was the only way of keeping the course at FTL speed reasonably straight. The slightest discrepancy in mass had lead to the early Hoppers being flung wildly off their path, tumbling and tearing themselves apart. It was far more reliable to rifle the ship for handling the unpredictable gravitational eddies that buffeted the ships protective field as it hit midpoint.

The rest of the crew had all headed off to their duty stations now, or secured themselves for flight. A few hours ago the observation deck had been packed in nervous silence as the updates had trickled over the intercom. People were attentive as one of the Pinches had been unloaded from the rack, and watched with silent fear as it had been fuelled up with antimatter. The SS Boseman had been lost that way; a slight fluctuation in the magnetic containment of the transfer line. A single atom tearing the line open, obliterating the ship. The “Black Bit” quantum-entanglement data feed told mission control everything.

At one point the ensign had halted his words for a second, and the whole room had bodily stiffened to a fearful acceptance that death was an instant away.

But now it was out there. In a few minutes time the antimatter would annihilate with it’s matter half, destroying the intensely charged field coils and creating a precisely focussed funnel of gravitational energy, pulling two distant points in space together for a few seconds.

Hundreds of sensors had us placed to within fractions of a millimetre of our set distance from the Pinch device. Close enough to be pulled into the correct portion of the gradient, far enough away not to be destroyed by the radiation blast or it’s monatomic debris. If the dispersing field around the ship didn’t fail, it would still overload at the other end, with the rhythmic popping of capacitor banks being jettisoned before they too exploded. And with luck we would find ourselves within 5 Au of our destination, still with enough time to correct for insertion into the target star-system. If not, then we’d have to pick another system and try another Hop. These things don’t work for short journeys yet.

Hopping so far in an instant only to spend the following couple of years coasting on the final leg seems an insult to some. Trust me that you need that rest to regain your witts. But it’s still a better option than spending an extra 70 years coming the scenic route, or arriving too close to correct your delta-V and passing right past your target.

The blast shields are closing. Next the forward 30 decks will be evacuated of personnel and air. The magic time’s coming up fast now. Wish us luck!

Star Trek meets Firefly

Short mulling on antimatter as a big-bang-battery for FTL drive systems.

Last year I think it was, someone suggested that the USA could soon use a “Z-pinch” device to create the needed energy gradients to allow a spacecraft to exceed the speed of light.

Aside from the frankly terrifying thought of interstellar expansion being sponsored by Starbucks and Disney, it’s a nice idea. But you still need a power source.

In Star Trek the whole ship’s powered by a massive anti-matter reactor. Oh, it has several small fusion power sources dotted around the ship, including some dedicated for the Impulse Engines if I remember rightly. Yet the anti-matter plant, the “warp core”, runs 24/7.  Before this gets too long-winded, I have trouble with how much power the ship requires. Okay, the warp drive bends space-time to extreme degrees, the transporters are essentially managing very controlled atomic annihilation and reconstruction, the replicators also do the matter-energy conversion as does the holodeck to some degree. It’s quite frivolous, but expected in an apparently “free energy” future.

Within our lifetimes though, the economy of having a sustained annihilation reaction seems questionable. However if I understand it, the Z-pinch concept is to create a sudden burst of energy, that would somehow flip the vessel across great distances. To be able to do that continually would need something like the Trek reactor. But since the Pinch seems to be a one-shot concept, you’d only need a single burst of energy.

Antimatter is a terrible thing, and controlling such a fundamentally unstable substance would be very tricky. However it does go bang very nicely. So if you need a sudden intense burst of power, such as for energising a Z-pinch device (possibly explosively in a similar method to an EMP device*) then a bottle of antimatter may be just the battery you require.

I recall hearing that the interstellar engine on Serenity, in Joss Whedon’s Firefly, was planned to be the sort of drive that wasn’t casually used, but that everyone held on for dear life and hoped it wouldn’t explode when turned on.

An annihilation-powered-Z-pinch would probably be a similar, terrifying experience.

* I wonder if any sci-fi writers have yet considered the use of a one-shot disposable FTL drive?