After much deliberation, i finally pushed the button last week and bought a laser cutter! Hooray!

Its a DC-K40III [eBay], which you might know as the Rabbit HX40a, Omnisign Pro 200, or 'cheap generic eBay chinese 40W laser cutter'.

Of course, being cheap, it has its problems. The first of which will be familiar to anybody who has used a chinese laser cutter before, the dreaded MoshiDraw. This is the software that drives these machines, and can best be described as FUCKING AWFUL. To remedy this issue, I am planning on replacing the Laser's mainboard with a LAOS board from laoslaser.org. This board is a ground-up replacement board , designed for entirely this application.

LAOS Features

• Based around an MBed LPC1768 Microcontroller, a 90mHz ARM chip with 32k of Memory.
• Ethernet controlled - no need to be on a single PC
• Printer Driver - LAOS uses CUPS, so is used as a regular printer.  The CUPS driver is cross platform, with support for Linux, MacOSX, and Windows.
• Direct printing from applications - You can print to it direct from Inkscape, so no worrying about converting to a PDF or HPGL file before printing.
• Open Source Hardware & Software - The most important one from my point fo view, this means the hardware and software are modifiable, so new and exciting features can be added!

More Photos

Well, r2 made it into a maze!  then crashed into the walls of that maze over... and over... and over... anyway, it diddnt work, and looks unlikely to work in the near or far future.

So i've spent some time fiddling with my CAD software, and now have a basic design ready to announce R3volution, my third micromouse!

Its a bit of an... unconventional design, with massive foam rubber wheels that i hope will give me a nice big contact patch, and therefore more traction on the ground.

The Gearbox is made up of 3 parts, a 3d printed 'backbone' and a pair of laser cut 'plates'

They are all designed in OpenSCAD, and set up in a parametric way, so i can adjust things like the angle of the motors and the height of the base plate without having to rebuild the entire cad files from scratch.  

It uses Faulhaber 1524SR motors with integrated encoders and 0.4 mod gearing, giving me a final gear ratio of 1:12.8, slightly higher than most mice (i think), but balanced out by the fact my wheels are HUGE.  The Axle for each side is a m4 bolt, mounted on mf84zz bearings and fixed to a custom wheel mounting system i'll be making on a lathe.

Electronics to follow when i've finished buying parts for & building the gearbox!

OK, I may have gone a bit mad after finding Seeed's Fusion PCB Service.  Yet another new board!

This is a simple board, which adapts these 3.3v USB to serial boards to an xBee socket.  If it works it should allow me to sell some cheap xBee Explorer style boards. 

Download Eagle Files

Download Gerber Files

UPDATE:  Dont use this board!  The SSOP16 package i used to make the library had one row of pins in completely the wrong order (who the hell does this?!?!)  Stay tuned for v1.5.

A new board!

This is a carrier board for the AS5035 magnetic quadrature encoder, it detects the rotation of a magnet above the center of the AS5035 IC, and outputs a quadrature signal.

Its untested at the moment, but i have 10 on the way, for use on R2.  Once tested, i'll have 6 units for sale through gobotics.net

Download Eagle files

Download Gerber Files

Download Eagle Library for AS5035

This is my review of the Duratool D00661 Soldering iron, sold in a kit by Farnell here for £30.38.  First, the kit contents:

The Solder station contains the station itself, and the iron.  The station has an integrated stand, which is easily removable by sliding the whole thing backwards.  It also comes with a slide-out parts tray / sponge holder, in case you need to store any small parts while soldering. 

The iron is a fairly typical unit, but comes with some handy features.  First off, the rubberized grip area helps you keep a good grip on the iron, so should help avoid burns due to dropping the iron.  The element is replaceable, so if you manage to burn it out you can get another for £1.64 without buying a whole new iron.  The tips are changeable, with a wide variety of tips available including: 1mm Pointed, 0.5mm Pointed, 3mm Chisel, 2mm Flat, and 1mm Bevel; each of which cost only £1.11.

The solder station unit has controls for shifting the temperature up and down, and an on/off button.  The dual-readout LCD shows both the current and target temperature, which is an incredibly handy feature for knowing when your iron is up to temperature.  As far as i can tell, the target temperature can only be set in Celsius, so those of you who measure in Fahrenheit or Kelvin are out of luck!  The station lets you adjust the temperature from 150 all the way up to 450 degrees, very handy for lead-free solder!

The iron takes under 30 seconds to get to temperature, and while in use, holds within 5 degrees of the target temperature.  I have noticed that when not in use, the temperature tends to be slightly on the high side (+5-10 degrees) due to the bang-bang style of temperature control, but this will rectify itself once the iron is used.  The iron comes pre-tinned, but i would suggest using tinning compound to make sure the tip stays in tip-top condition.

So, we come to the actual usage of the iron.  I found it works very well for the cost, almost as well as some £100 irons i have used, and far better than any other £30 irons.  I used the included 1.0mm tip to do some SMD soldering on a new R2 board, and very good results.

In summation, this is a good iron for anyone wishing to do hobbyist work, and will work well all the way down to tiny SMD equipment.  I would definitely recommend it to anyone in the market for an iron.  Its not just good for the price, its good!