3D Printing

During the Covid-19 lockdown, I started a new hobby – 3D Printing at home. At first this was to print customisable parts for my wargaming hobby I’ve had since I was 11 (I’d grow out of it, they said), but I’m beginning to find new applications.

3D printing a ‘leaky dam’. Left shows a virtual 3D model captured by Josh Wolstenholme using photogrammtery. Middle is the 3D printed version before painting with supports attached. Right shows the model painted by me (this was fun). There were a few steps in between! You can view Josh’s 3D models here on SketchFab.

I use a resin printer (Elegoo Mars Pro). This uses UV light from a screen the size of a mobile phone to solidify layers from a vat of liquid resin. This is different from what most people think of when you mention 3D printing, most people are familiar with FDM printers that use a heated nozzle to melt plastic filament into layers. Resin printing is able to produce much greater detail than FDM but you have to negotiate the resin, which is toxic to you and the environment if handled poorly.

Consequently, I print in my garage when the outside temperature allows (March to October in the UK). I make sure I have the correct PPE: nitrile gloves (so the resin does not seep through them), goggles, and a face mask (to catch stray splashes). My area is well ventilated, close to the garage door and I often have a fan running when I’m working in there to move the air around.

3D printed cityscapes. These prints were made from LiDAR data processed using the DEMto3D tool in the open source QGIS. The first image is a print of Southsea, Portsmouth, UK, made for my in-laws. The second is the city centre of Hull, UK. The third image shows the processing of the Hull scene in the ‘slicer’ software Chitubox. The prints were painted by me and framed by Amy Skinner.

Something to consider with resin prints is waste material. When a print is finished, it needs to be washed. I choose to use a water washable resin and I clean them in pickle jars (they have a handy basket), using the same water all summer and topping up as I need. You should NEVER wash under a tap or pour used water down drains – uncured resin is harmful to the environment. To dispose of it, I blast the water under a UV lamp to cure any resin and allow the excess water to evaporate away in the sun, before bagging and binning the solid waste. Likewise, all paper towels and excess resin (from supporting structures) are put under a UV lamp before being disposed of. Sadly, there can be a lot of waste and I’d be keen to learn about ways to reduce or reuse any of it.

My first 3D print, processed and printed for me by Rob Miles in 2015 on an FDM printer. The data is from my Humber model and Rob applied a 50x elevation exaggeration to pick out the shape of the land across this large, flat region.

3D prints of the NERC PEGASUS field site, the Chumpe Glacier, Peru. The blue on one of the prints is the extent and heights of the glacier ice, whilst the all grey print shows the land elevations without any ice. Note: I managed to break one of the prints apart whilst snipping off excess resin but it went back together ok.