If I use resin printing to make moulds or patterns for the ABSS project that are the size of a large adult shoe sole, then the typical off-the-shelf consumer-grade resin curing boxes will not be suitable. They are far too small. Fortunately, I spent an afternoon with a knowledgeable local 3D printing expert, and it turns out that building one is simple if you can access some UV lamps of the appropriate wavelength. Craig from 3D Print Monkey sold me a pair of Elegoo customer return parts that were perfect for my needs. These lamps were removed from a batch of Elegoo resin printers fitted with a faulty mechanical part, which made the lamps too focused for use in a printer. As a result, they are just sitting on a shelf with no purpose, so now I have two of them in my possession to build a resin-curing machine.
Below this large lens array is an aluminium PCB filled with high-power UV LEDs. The entire assembly is attached to a heavily finned heatsink because it’s rated at about 60W and gets quite warm. It’s satisfying to repurpose this faulty part into something I can use!
If I add a simple rotation stage, I can leave the unit running unattended for smaller prints. This unit is available on Amazon and is intended for video photography. It is powered by an 18650 cell, so no wires are needed. I covered it with aluminium tape to maximize the reflectance of the UV light inside the container. When curing larger objects, this unit gets removed, and it is sometimes necessary to cure in stages by manually moving the object mid-way through.
To ensure consistent results, I installed a timer module purchased from Amazon. This device retains previous settings to withstand power outages, making it easy to set up and forget about.
I created a hanger for one of the UV units by bolting together some metal brackets. I placed the second UV unit directly onto the bottom of the container. The container was lined with aluminium foil tape to maximize the internal reflectance paths. This ensures that the UV light penetrates the object from every angle, resulting in an even cure.