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MrCNC - part 1

Today I present the latest project to come out of my workshop: a CNC machine! CNC stands for Computer Numeric Control, which is a fancy way of saying computer-controlled. A CNC machine has a rotating spindle that is movable in 3 dimensions and is able to carve, cut, and machine objects according to the input file on the computer.

Building it has taken most of the past month. An initial plan was roughed out on the computer and I started ordering bits online.

The first bit to be built was the bed of the machine. I made this out of Open Beam, which is aluminium extrusion, 15x15mm with built in slots to accept M3 nuts. This makes it easy to bolt the bits together, like some kind of giant Meccano set. The corners are chopped up T connectors and help square things up.

Ends for the bed were made out of 6mm MDF, which is g...

A vertical drill press

If there is one thing every engineer needs, it's a drill press. And I may be an engineer, but I did not have one. So I decided to make one. The thought pattern went something like this:

I have a pile of fairly crude model railway carriages that aren't being used. I should reuse their components and make my own carriages. I could cast the bodies. I need to make a master for the casting. I could design it on the computer and get it laser cut? No, that would take too long (1 month waiting period on laser cutting!) I could cut them out by hand? Mmmm I could, but it would be hard to get them perfect . If I had my own laser cutter I could cut them myself. Hmm… no, laser cutters are too expensive, and too dangerous. What if I had a machine that could cut them, but not using a laser? Michael does some googling … hmm, that machine would be called a CNC router. Does some more googling… and they can be very accurate and cut almost as ...

Introducing Utrainia

I haven't written in my blog for quite some time, but that doesn't mean I haven't been active. Moving to Masterton meant I had to leave my model railway behind, no small sacrifice! However I've been busy modelling while up here, just on a smaller scale.

In my 6 months up here I've built 3 small N scale modules. Each one is a small self-contained scene, 750mm long by 300 to 400mm wide. So far I have a coastal scene based on the Kaikoura Coast, a blizzard scene based on Marias Pass, and a prairie scene based on a lonely grain elevator near Lind, Washington.

Each module connects together to form a larger railway. They're all small and lightweight, and easily portable, so next time I move they can come with me.

I've been haphazardly sharing my progress here and there, but never on my blog. One day while pondering over dinner what to call my railway I had a brainwave: Utrainia . Utrainia is a portma...

DIY earrings

Recently it was my six month anniversary with Rachel. She'd been dropping many "subtle" hints about all the things I should buy her to celebrate, but why buy when you can make?? So since jewellery featured so prominently in her wishlists I decided I'd make her some earrings. After tossing around a few ideas I happened across my old metal casting gear and half a white metal ingot, which gave me the idea of casting some earrings. And so with much vigor I launched into my next project.

Step one was to make a postitive to cast from. I dug out my trusty supply of blue plasticine and set to work. Working with a scalpel on an old mirror I made up positive and a box to hold the plaster.

Step two was to make the negative. I poured some plaster into the mold and then put it on a vibrating table to vibrate out any air bubbles. The plastic tray is to catch any spills.

A few hours later it ha...

Mr Blimp

We have a lot of helium here at the flat, a lot! As in two canisters worth. But anyway, I started my weekend by cleaning the garage and doing the washing, but by Saturday afternoon I was all done and had nothing to do. The thought of wasting an entire weekend without making something sent shivers through me, so for whatever reason I decided that I would make a cellphone controlled blimp. I suspect that decision probably had something to do with the package I'd just received from China, that contained a $6 bluetooth serial interface board. I was itching to use it!

A quick rummage around later and I found some spare LB1973M ICs, perfect for driving two small DC motors. Also in my DealExtreme package were a couple of mini solar toys which had some very small motors and gears, ideal for powering this thing.

A few hours later and I'd designed my circuit:

Based around an Arduino, i.e. an ATMega168. The power comes from a sma...