Mapping the mine with 3D printing

3D Systems and BCA Consulting combined forces on an ambitious client venture to 3D print a mine map that could be broken down by project phases. Australian Mining writes.

3D printing, less commonly known as additive manufacturing, is finding a foothold in the mining industry, particularly for the construction of specialist parts and displays.

It is also useful for the construction of 3D maps, with recent leaps in technology allowing cartographers and model-makers to produce work with increasingly accurate details. This is something cartographer Ian Widdowson discovered when he embarked on an ambitious mine mapping project with 3D printing specialist 3D Systems.

Widdowson joined resources and extractive-focused consulting practice BCA Consulting (then Bell Cochrane) in 1986 and has worked on countless projects. Recently, he was working locally for a Victoria-based mining client that approached him with an unusual request.

The company wanted to demonstrate the environmental impact of a planned mine project to locals and government officials in simple terms, including how operations were going to pan out in various phases over the next 25-30 years

The client, a Victorian basalt miner and Construction Material Processors Association (CMPA) member, was adamant the model show that much of its operation would take place underground with minimal visual disturbances, while also conveying the different stages of excavation in sequence to help stakeholders contextualise the impact of each phase spanning the 30-year project.

Widdowson came up with the idea of presenting a jigsaw-like 3D relief map of the project area, with removable parts that indicated the various project phases in five- to seven-year “segments”.

Though skilled at producing 3D models by hand, Widdowson entered the 3D printing arena for the first time in his career to develop the project. He decided to approach the Melbourne-based Asia-Pacific branch of 3D Systems On Demand Manufacturing for help.

Typically, 3D printed items are envisaged as vector-based models with the use of computer-aided design (CAD) software before being interpreted and 3D printed. While several methods of 3D printing exist, a technique similar to selective laser sintering (SLS) was ultimately chosen for the project.

The SLS process uses a nylon-based powder that is scanned by high-power CO2 lasers to fuse plastic powder particles together, layer by layer, to form a solid model. Producing parts using 3D printing was new territory for Widdowson.

“We wanted to demonstrate sequencing — the flat staging of what was proposed for extraction at the site over a 25–30 year period,” Widdowson explains.

The map initially began as a 2D drawing then built in 3D vector graphics by Widdowson and a colleague using software programs such as MapInfo and Minesight, which was used to convert 2D images into 3D.

3D Systems’ role was to then translate the vector renders into physical objects. This is where prototyping consultant Jon Bloomfield came in, using the company’s own ProJet CJP 660Pro 3D printer.

“Jonathan was the conduit for us,” explains Widdowson. “He understood what I wanted to try and demonstrate with the jigsaw concept of placing the pieces back together to end up with a smooth surface. He was definitely the person to facilitate that.

The 660Pro uses a powder-based system similar to the SLS process; however, instead of a nylon-based powder, it makes use of a gypsum-like material.

“The great thing about the 660Pro is that it incorporates an overhead inkjet system that selectively binds the surface of a powder bed as it slowly lowers, eventually giving shape and colour to a model. The model is then airbrushed clean of loose powder and strengthened in a dip of liquid infiltrant,” explains Bloomfield.

“After discussing a number of key technical requirements, Ian and I both agreed that producing a model that could convey to stakeholders the full extent of the extraction, in terms of timeline and scale, would be necessary for it to have the greatest visual impact and fulfil Ian’s initial vision.”.

In a process similar to photogrammetry, the model’s detailed surface texture was created from aerial JPEG photography that was distorted using geo-referencing in order to correctly wrap around the 3D terrain without warping.

In addition to the 20 by 29cm jigsaw-based model, a second model of 12 by 29cm showing a volcanic scoria cone adjacent to the client’s project area was built.

While the immediate area around this scoria cone was not a part of the project site by itself, Widdowson and Bloomfield felt its inclusion could provide additional relief details that added a decipherable sense of perspective for observers, particularly to show the relative depth of the mine.

The areas of the model showing the extraction points were coloured off-white-to-grey in order to make sure underground areas were readable and provided a reference to the project’s status as a basalt mine.

“Obviously the geology of the area changes,” explains Widdowson, “and because we’re on the edge of a scoria cone, some of the material there might be a pinky grey.

“We made the decision to use that one colour to keep things simple so that when people saw that colour they understood that it was beneath the surface from that point of view.”

In addition to the models, laminated aerial overlays were produced that could be placed over the models to show the various buffer zones. The models were placed on the table first and then the overlays would lay at the top of the model with the model poking through to provide a broader context for the overall mine site and the surrounding area throughout each individual phase of the project.

“After months of working together to bring this model to life, it was clear that Ian’s concept of visualising excavation projects in this way could really change how future site proposals within the mining industry are presented,” says Bloomfield.

3D Systems and BCA set a precedent with the finished project, which took several months of liaising from concept to execution. Widdowson claims he had never seen a mine model built and utilised in such an extensive way in 30 years.

“It was only because Jon was very conducive to listening and comprehending what I was trying to make — and because he knew the capabilities of the 3D printer technology — that we worked backwards and forwards to ensure we could actually get an end product that was going to tick as many of the boxes as possible,” says Widdowson.

“From that point of view, he had a wonderful ability to understand what I was saying. I’m sure there would be quite a lot of people who would shy away from it but he embraced it.”