SLA 3D Prints

Please don’t look too closely at my keyboard

The first I heard of 3D printing machines was in the mid-90’s; I remember hearing of things described as “Santa Claus Machines” (perhaps this old Wired article had something to do with the name) which used computer-controlled UV light to harden a special resin. Dad bought a little bit of the resin, which I remember hearing was hideously expensive, and we had grand plans for making things with it, but we still haven’t got around to finishing the required CO2 laser’s power supply…

Fortunately, here in The Future, we can easily and inexpensively get UV lasers with power supplies, or even simple UV LEDs (remember, when that Wired article was written, blue LEDs were still a year or two away from Digikey’s phonebook-thin pages). The resin is still fairly expensive at ~$150NZD/L, so you’ll not want to be asking Santa for anything too big, but it’s approachable.

Of course, now everyone and their uncle has an FDM-type 3D printer, so dealing with the expensive resin and UV light isn’t so appealing anyways…

Except! SLA printers work really really well, and you can pay someone else to do the printing for you. Not even very much money – our friends at Dangerous Prototypes sent me the part at the top of this post (along with some circuit boards) for $3USD, and look at the quality!

3D printing in commercial products

I was recently tinkering with a thing at work, and was surprised to find that a couple internal parts of this thing are 3D printed using a printer of the same type we’ve got at the makerspace!

This is a Thinklabs One digital stethoscope, available for sale online through mainstream retailers for about $500USD. Check out the grey plastic ring around the blue part.


Talk: 3D printing

Here’s some references from the 3D printing talk:

First of all Thingiverse where you can find 1000s of things to build and make


The “reprap host” slicing application can be downloaded from

you’ll need a working Java runtime to use it.
You need to download the config file for our working reprap from:

install it in ~/.reprap (or wherever else reprap host stores stuff on your computer). To slice:

  • press ‘load STL’ to load an object
  • drag the loaded object a little on to the be – about 1 square diagonally
  • press the green ‘Print’ button

always quit and restart reprap host between objects – put the resulting ‘.gcode’ file on a USB key and bring it in to print


There’s also a design guide to help you make stuff that prints well:

OpenSCAD – the 3D CAD program I was using is available at:

Instructions for repairing bogus STL files:
You can also use netfabb