BigRep has solved a major barrier to large-format 3D printing in a very ingenious way.
The problem being solved is warped prints.
Wait a moment, you say, “hasn’t that already been solved”.
Well, yes, it has – but only for smaller machines. Smaller desktop units would typically employ a heated print surface that keeps the temperature of the first layer of plastic just at the point where it won’t warp. Too high and it would deform, too low and it would contract due to cooling and a warp would develop.
Warping is an insidious problem because it not only deforms the object’s shape, it can also cause the print to fail entirely if the print becomes loose from the print bed. I hate warping!
But it’s a property of the majority of plastics used in 3D printing. When heated, they slightly expand. When cooled, they slightly shrink. And you need it hot during printing and cool to use the object. It’s unsolvable, or so it would seem.
Major players in the industry overcome the problem by simply heating their build chambers. Stratasys, for example, tends to keep their printers at around 70C internally during printing. When the print completes, the plastic simply cools uniformly in all directions, preventing warp.
But open-format large-scale 3D printers such as BigRep’s ONE are more affected by this problem than smaller machines, simply because larger prints offer more warp opportunity: shrinks are amplified over the longer axes of the model.
BigRep overcomes this partially by printing in PLA and using a heated print bed. But the problem is that PLA is not an appropriate material for all purposes.
If ABS plastic was attempted to be printed on a BigRep or other unheated large-format device, it would surely warp catastrophically, making large ABS prints nearly impossible.
A few years ago BigRep had the notion of heating the build volume, and they even built a prototype of such a machine, shown here.
However, that extra hardware and control systems dramatically increased the price of the unit.
Was there another solution? Yes! BigRep CEO René Gurka hinted at possibility of changing the plastic rather than changing the hardware earlier. If they could identify a plastic that did not warp – or at least warp far less than ABS – the problem would be solved WITHOUT needing a change in hardware!
And that appears to be achieved with their announcement of BigRep Pro HT 3D printer filament. They say it’s the:
World’s first high-temperature filament for 3D printing in an open and unheated build chamber with heat resistance of 115°C
Even better, this stuff is biodegradable, weatherproof and has UV and heat resistant properties. It could be a practical alternative for ABS in such large machines.
The new material is available for order right now, and comes in rather large spools for use in such huge machines:
- 2.5kg €129.95 (USD$145)
- 4.5kg €239.95 (USD$268)
- 8.0kg €419.95 (USD$470)
This should make 3D printing a great deal easier on the BigRep equipment – and indeed any other large format machine capable of using open filament.