2011-10-14 08:38 pm
Entry tags:

Limb Embiggener version 2

2011-10-14 19.42.09

I have taken some photos of my new version of my "limb embiggener" where I've uses bolts instead of fabric tape for the joints.

It still seems much easier then the original skeletonics system that inspired me, and more sturdy than my previous mechanical arm. Hopefully there's enough information to give anyone a good start to making one.

The Perth Artifactory had all the tools I needed - drill press, saw, clamps, measuring tape.

I bought some more bamboo and some long bolts, I think 3/8 inch diameter as the metric ones at Bunnings seemed either too wide or too short, cut some bamboo, drilled the holes in the bamboo, big enough for the bolts to go through either easily or with a push, and fit it all together.

Taped on the bicycle brake from the previous arm, originally from a local bike shop, to be the claw.

The holes through the bamboo were sometimes visibly misaligned, so when I laid the bamboo down with one hole vertical, the other was off vertical. I may have had to widen a hole now and then to give it enough slack to cope with the misalignment, and but generally it seemed remarkably tolerant of my errors.

To wear it, I strap it onto my arm with double-sided velcro - the stuff with hooks on one side and loops on the other.

All my mechanical arm pictures on flickr:

Tensegrity: one of the principles I used in designing it - each length of bamboo should be under compression or tension only, it should not be under significant bending stress. Where it was, I reinforced it with pieces to take the load as compression and tension instead. That's basically how I added the triangles.

There is still a bit more reinforcement that could be done, but it would just help take the weight of parts of the arm, not whatever load is held with the claw.

Some of the bolts stick out a fair bit, so I have to be careful not to scratch things or myself with them by accident.
2011-06-11 09:09 pm

Whuffie credit system

An alternative/complementary trading system different from money can be created, taking inspiration from Ripplepay, LETSystems, Whuffie, and BitTorrent's tit-for-tat selection of peers to swap data with. I am working out how it could work.

It doesn't have all the advantages of money, so it could work better as a supplement than as a replacement.
Read more... )
2011-06-11 07:21 pm

Famous, kind of

The top google search result for limb embiggener was this picture of my unpowered exoskeleton arm!
Extendor Articulated Bamboo Exoskeleton Limb Embiggener

But since seeing Ghost in the Shell I now want four wheeled limbs like the Tachikoma's legs.
Read more... )
2011-04-26 10:33 pm


Ever since Peter Hillier showed me the youtube video Skeletonics showing an unpowered mechanical exoskeleton that roughly doubles the wearer's reach I've wanted something like that.

However I wanted it to be cheaper and quicker to make. I am starting with just a single arm. My first version was a roughly 0.5 scale prototype made from plastic straws held together with sticky tape at both the plain joints and the rotating joints. It worked remarkably well initially though the sticky tape joins didn't last that long. I think it took well under an hour to make.

My second version was made from bamboo with bamboo sticks as the rods ($4.60 at Bunnings for more than I've used so far), cloth tape for the joins, and a $26 worth of bicycle brake parts to substitute for a hand. It took maybe 4 hours to make at the Perth Artifactory which had clamps and saws to cut the bamboo to length.

Issues with the current version:
The bicycle brake hand has a very limited range of motion. But it can still grip a can of soft drink.
With no straps yet, I have to hold the shoulder joint in place with the other hand.
The cloth tape keeps coming loose.
Some of the joints need to be quite loose for the sticks to be able to rotate past each other.

Well I've made the straw version and the stick version, if this is the three little pigs the next version should be made of brick. Unfortunately it's too heavy and brittle.

Possible upgrades:
Straps so it's attached to my arm instead of just held by hand.
Bolts through drilled holes instead of cloth tape. This will require adjusting the design so the rods stay out of each others' way.
Aluminium tubes instead of bamboo. The bamboo's worked pretty well so far though.
Cover the mechanism so it looks more solid. Could use metal foil or fabric.
Also I should get some more pictures up online. Jason put a video of me lifting a drink bottle with the arm here

I haven't worked out how I'm going to upgrade the hand yet. It may end up being more work and than the whole rest of the arm, it's already the most expensive part.
2010-07-26 09:40 pm

My sore throat - the movie trailer

The germ was a more worthy foe than it first appeared.
Last year I thought I had defeated it for good. The cold. The flu. The dreaded lurgy.
In the epic battle between good and a sore throat I thought I was invincible,
but my arrogance was unjustified, and now it's back!
It honed in on my one weakness - insomnia, and has thereby struck a blow against
my immune system.
Can I outwit the tenacious microbes with a combination of wacky ideas
from the internet and logic, or am I doomed to week-long illness a couple
of times a year for the rest of my life?
2010-01-17 10:09 pm

Twitter is the latest battle in my war against internet addiction.

I wouldn't go without the internet, it's so full of good stuff. But it does challenge my willpower.

Every now and then I find a treasure trove of information or conversation. TV Tropes, Facebook and livejournal were like this for me before. The more I read, the more links to other interesting stuff I find. Or I move the web browser closer to my brain. First a PC in my room, then a laptop I could read in bed, now a phone I can keep in my pocket and read anywhere.

The latest one's Twitter, and all the links to web pages on there. I've discovered there's a website with instructions for making aerogels, and encouragement to make them. I've discovered heaps of articles about programming. I discovered a video demo of an augmented reality system to help soldiers repair tanks. I discovered an article about making money as an independent musician. And of course heaps of people writing about twitter itself.

I've also recently discovered Kevin Smith's podcast called Smodcast, but that wasn't from twitter.

As before I tend to read so much stuff I forget most of it, which is kind of unsatisfying. And I don't get to bed early enough.

Advice to self: write down interesting links to read them later. Take time to write my own thoughts instead of jumping from one to another of other peoples. And don't get hooked on reading the infinite supply of people arguing with each other.
2008-03-04 07:17 pm

Project: Playfulness and delight.

I just watched My Neighbor Totoro and those kids really knew how to have fun and appreciate their surroundings (mainly by running around exploring it). I don't think I was that relentlessly playful when I was that age. *envy*. So I need a plan to become more playful (ha ha ha!)

Step 1: make silly faces.
Step 2: sing loudly in the car. (only by myself, or with others?)
Step 3: considering making farty noises, but some people don't appreciate the humour. I dunno.
Step 4: identify other playful people and copy them.

Running around doesn't work so well. Sometimes I run with impatience if walking is too dull. People might think I'm a criminal if they see me running down the street. Eating strange food mixtures is something I already do. Maybe I'll do it more often.

I'm not quite sure how serious I am with this plan. Partly serious I guess. But amused.

Oh yeah, step 5: solicit ideas from anyone who's reading. Not that I'll necessarily want to do any, I can be pretty self-conscious. But I like options. And it might be funny to think about.
2007-10-24 05:07 pm

Science fiction goodness

I haven't read any of flurb.net yet, I've only heard one story from it elsewhere (Cory Doctorow's I Rowboat, recommended), but I'm looking forward to doing so.
Spotted in warrenellis.com syndicated lj feed via dalekboy
2007-09-13 06:51 pm

Pssst. Perth cyberpunk convention. Pass it on.

Night's Edge could use some promotion,and is also looking for panelists and volunteers.

Date: 10th and 11th of November, 2007
Place: Emerald Hotel, Perth
Cost: $50 Full, $45 Concession
E-mail address: nightsedgecon@gmail.com
Blog where I got that info: http://nightsedge.blogspot.com/
2007-08-23 10:32 pm

(no subject)

I left the dalek toy thay says "exterminate" at Adrian's birthday party last weekend. Anyone else who was there know where it ended up?
2007-08-12 12:25 pm

(no subject)

I was informed last night that you can stick a cup in a shirt pocket. It's called ... pocket cup. It really works. Thanks [livejournal.com profile] karenanning (and credit to the Mighty Boosh for the idea)
2006-12-13 07:09 am

Man single-handedly moves big rocks, barn

I've long been interested in how stuff can be done without modern technology or expensive machines.
This guy moves enormous weights using wood and stone.
2006-11-14 11:34 am

Zombie Walk

Just saw an article on Wikipedia about people dressing up as zombies and walking through city streets with that walk zombies have. The world is full of amazing things. There's something a bit strange about well-organised zombies. One of the websites says "walk with fellow zombies" and I imagine these isolated zombies (maybe there was a small partial apocalypse) sitting at home and searching for each other on the internet. And maybe having trouble using the computer. Come to think of it, they might not have a place to live, so they go into a library or internet cafe and ask for help doing it, resisting only with great difficulty eating the staff.
2006-10-30 05:21 pm

ChessRogue and the Roguelikes

I've been trying out some of the new smaller
roguelike games, some which have been made for 7 day roguelike challenges.

ChessRogue was one I'd played before, but there's a newer version which allegedly makes it a bit easier on the later levels. It breaks a lot of the roguelike conventions. There's no hit points, you can see the whole level, there's no character levels (but there is character advancement) and there's several other differences. I think the character advancement is more interesting actually, it's very satisfying getting the new powers. The game feels partly like a series of puzzles: learn a way to defeat pawns until you get the power that makes that easy, then how to defeat the mobile bishops (some are easy since they're stuck in a corridor with no diagonal moves available). Defeat enough knights and they become easy, except in their ever increasing numbers they can be a challenge. I really like this one for its novelty relative to other games.

Quest for Pants I found this one a bit frustrating, and it reminds me of the original rogue. Not much more to say about it since I haven't played that much. Still quite impressive for a game made in 7 days.

Frozen Depths seems like it was made to demonstrate an alternative to food and hunger. The temperature system has some similarities and some differences compared to a hunger system, and it seems like much more of the focus for the game. Starting off naked is a little unrealistic but never mind. The monsters do somehow have a different feel to other games, but I wonder if it's just their names. The icey depths also feel a bit different from a regular dungeon. This one's interesting because it makes the setting different with lots of small differences.

Tried some of the windows games in wine, with two problems: two of the diagonal movement keys didn't work, and the most interesting one, Dwarf Fortress didn't work.

Played just a little bit of Z-Day the zombie-themed game, but I think I need to read the instructions to get much further.
2006-10-10 11:50 am

Folk corollaries

These are some things I came up with a couple of months ago.

Look before you leap.
He who hesitates is lost

Get lost before you leap

Practice makes perfect
But nobody's perfect

Nobody has ever practiced

There's no such thing as a free lunch
The best things in life are free

There's no such thing as the best lunch

If we further postulate the existence of at least one lunch, it follows that there is an infinite sequence of lunches of improving quality, because if you ever got to the end of the sequence, you would have found the best lunch.

Look before you leap
Never look a gift horse in the mouth

Never leap into the mouth of a gift horse
2006-10-08 09:02 pm

Corn smut

I saw Mexican truffles on [livejournal.com profile] drhoz's LJ. That would be fun to offer people to eat. I wonder if it's available in Perth.
2006-10-08 12:56 pm

Live journal stuff

Now I've started posting I should subscribe to my own journal.

Stuff to write about:
Uni Graduation
Mexican Truffles (that's easy, I'll do it now)
2006-10-06 10:21 am

That name's already been used

I heard the new Commodore Amiga being promoted on radio. In print they'd spell it Omega, and it's clear that it's a car from Holden, but it's still funny hearing the name.