Sad laser

Pro tip: Never accidentally run your laser without first turning on the water pump.

There was a loud crackling noise and now nothing.

Stay tuned for our next exciting installment where I attempt to source, fit and align a new laser tube.

It's only a 40W invisible laser beam triggered by 20kV and surrounded by water, WCPGW?

Slicing

There are several 3D printers built from mainly lasercut parts. I've looked at the printrbot-LC and the Prusa-i3/Graber-i3.

Unfortunately, they all have parts too large for my small laser cutter. Without modifying the mechanism, I can only reliably cut about 30x20cm. All of the designs also need 6mm thickness material, which I haven't tried cutting.

So, I'm experimenting with building the large parts in two 3mm layers with each layer sliced at different points.

So far, so good...

Storage

I have a lot of junk.
Having more storage for all my bits and pieces is useful, so I cut out and assembled some of these open top boxes. Originally, they were meant for 5mm MDF, so I scaled the design for the 3mm plywood I have.

Very useful.

Accuracy test

The DC-K40III is mechanically sound. But, the controller board and software aren't. Once I had Moshidraw working, one of the first tests I did was to cut out the spirograph business card to check whether the scaling was right.

Not bad at all.

Nexus 4 Charging Dock mk.1

To charge my Nexus 4 mobile phone while sitting on my desk, I designed a simple dock.
The USB cable is embedded inside it and held in place with a little glue.

http://www.thingiverse.com/thing:126459

It works, but the design isn't quite right. The notification LED on the phone is obscured by the base and it could do with being a bit bigger for stability. Next time, I may try to angle the phone a bit as well.

But, this is the magic of rapid prototyping!

Ratchet rattle/gragger

Here's my design for a spinning rattle, a bit like a traditional football rattle or a gragger.

http://www.thingiverse.com/thing:33910

To assemble it, you'll need some glue and a rod, I used a small section from a bamboo cane.

Warning - this thing is noisy and really irritating - it was banned from the house within minutes.

Othello (aka Reversi) mk. 1

Othello is a game I've liked for a long time. In the game, there's an 8x8 board and 64 pieces. Each piece is white on one side and black on the other.

Here's a design I made for a simple board and some pieces, etched on one side, plain on the other.

http://www.thingiverse.com/thing:124002

My first attempt at cutting a set of pieces worked, but I'm not satisfied.
I'm seeing two problems:

• The laser is firing slightly late when starting an arc path (hence the unetched gaps)
• The (old) air compressor wasn't working well and allowed some pieces to get scorched (this should now be fixed)

A toy cart

I was curious to see if I could build a working laser cut toy cart without needing any glue, screws or other materials.

The square axle works surprisingly well and pushes to fit with the wheel.

http://www.thingiverse.com/thing:124712

Better air assist

My lashed up air assist stopped fires, but wasn't very good.
I still got bad scorch marks on cut edges and the tyre inflator air compressor was very noisy.

What I needed was a better way to direct air at the cut. I found another user of the DC-K40III, who gave me a design for a 3D printable nozzle. The STL file is here.

Using Shapeways, I ordered a 3D print (cost ~20UKP, took under a week to deliver) and got back this:

It's now fitted to the laser head along with a small visible laser showing a crosshair.

I replaced the noisy tyre compressor with a cheap airbrushing compressor (AS18-2 from eBay).

Now, I get very little soot left on cuts and I can hear myself think.