Author: Madox

Parametric Modelling in Google Sketchup and Ponoko friendly SVG export for Sketchup

The problem

I’ve recently signed up Ponoko’s Prime account and wanted to get something made.  I rather into a rather annoying problem, Alibre Xpress doesn’t have a SVG export.  I needed a way to design something and export it as SVG.

I’ll admit the long post title is a problem too 🙂

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Rapid Prototyping – Mechanical Iris Diaphragm (New & Improved!)

Last time around I ran into two major issues.

  1. Tolerance between moving parts was too tight.  My pivot pins on the inner ring were pretty much jammed into their holes…
  2. Fragility of the part.  Using 1mm diameter pivot pins using the detail material (weak) was not a good idea.  Coupled with the tight pin problem above, it meant I accidentally snapped a couple of pivot pins off the blades when I tried to rotate close the iris.
  3. Coarse triangulation of the exported STL which made the two rings too ‘blocky’ to rotate freely with each another.  My fault, fixed by (labourously) tweaking/experimenting with Alibre’s Export.

So how did I fix it all?

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Cute colourful heart rings!

Heart Rings painted by Peter Paul (Shapeways)
Heart Rings painted by Peter Paul (Shapeways)

I just ran into this Shapeways Blog Post and couldn’t resist reposting this photo of those colourful ring fest.  If you’ve read earlier in my mechanical iris diaphragm post I was just playing around with Alibre Xpress and see if I could design a ring using that, guess someone at Shapeways thought they were cute and printed them out!  The rings are painted using a water based paint, I just wonder how it’ll look with an acrylic paint to smoothen out the surface somewhat.

Compiling a toolchain for ARM7 under Ubuntu

Well this chronicles my first attempt at compiling a toolchain for programming ARM’s in ELF code.

Why do I need a toolchain for programming ARMs?

  1. I found a LPC2378-STK development board in my room
  2. I want to give ARM programming a try (PS WinAVR is great for programming AVRs)
  3. I found I have some spare ARM7 LPC2378’s lying around (WTF?) and thought I’ll actually complete my Chumby Speedometer on my car project!

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Cowsay? Madoxsay! Fun (or oh so wrong) things in Ubuntu…

It started with a colleague walking by my desk today and asking me if I had ‘cowsays’ installed on my machine, never having heard of it before he dared me to just try run it.  A short command not found and a subsequent apt-get install later… I didn’t know whether to burst out laughing or slap my forehead.

 ________________________________________
/ This is a very very useful and         \
| productive program available in Ubuntu |
\ and other Debian distributions...      /
 ----------------------------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

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Java not working on Firefox 3.0.4 in Ubuntu 8.10 Intrepid Ibex?

Well it was just nagging me, and for anyone who runs into this problem here’s the solution (to the ever moving Firefox path problem)

cd /usr/lib/firefox-3.0.4/plugins

sudo ln -s /usr/lib/jvm/java-6-sun/jre/plugin/i386/ns7/libjavaplugin_oji.so

Assuming you already had the sun-java packages (anyway if not just get it).

Reverse Engineering the Mazda CAN Bus – Part 1

Controller-Area Network or CAN Bus is one of many automotive communication buses for communications between various ‘car computers’.  Information such as speed, fuel consumption, accelerator pedal position is all transmitted between the various controllers of a car akin to ‘fly-by-wire’ control systems of aircraft but I guess ‘drive-by-wire’ is more appropriate in this case.

There are other rival bus technologies include LIN (Local Interconnect Network) which is supposed to be a lower cost alternative to CAN, but I’m not interested in that.  Why?  My car uses the CAN bus, not LIN, not Ethernet.  So lets go about figuring what can be gleened from the communications whizzing around my car!

Aside from CAN bus, my car has a pig too. This photo is from 2 years ago and the pig no longer has the tail or the tag on its ass...
Aside from CAN bus, my car has a pig too (Long story). This photo is from 2 years ago and the pig no longer has the weird thing hanging from its belly or the tag on its ass...

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