FDM 3D printing in Sydney

Filament comes off a spool and gears push it into the hot end, where it melts at 200 °C or more. A 0.4 mm nozzle lays it down as a thin bead, tracing each layer's outline and then filling it in. The next layer goes on while the one below is still warm enough to bond.

Standard quality uses 0.2 mm layers. Finer 0.16 mm or 0.12 mm layers give a smoother surface but cost more, because the part takes more layers.

Our FDM printers have an enclosed, heated chamber, which ASA needs to print without warping, and they feed filament from sealed boxes that keep it dry. Damp filament prints stringy and weak. The biggest part we can print in one piece is 400 × 400 × 400 mm.

An FDM part isn't solid plastic. It has walls around the outside, solid skins top and bottom, and a lattice called infill in the middle. Most of the strength is in the walls, while the infill holds up the top and stiffens the part without the weight of solid plastic.

The strength options on the quote page add walls and infill. More of either makes a heavier, tougher part, and the price updates as you change them.

Each layer fuses to the one below, but that join is never quite as strong as the plastic along a bead. PLA tests at about 35 MPa across its layers against 39 MPa along them. For a sharp knock the gap is far bigger: an ASA bar struck across its layers takes about an eighth of the blow it survives the other way.

So a bracket printed standing up can split along a layer under a load it would carry lying flat. Pick an orientation on the quote page, or leave a note about which way the force goes, and we'll lay the layers to suit.

Every layer needs something underneath it. A wall leaning out up to about 45° prints cleanly, but past that the plastic droops and needs supports. A flat bridge between two points prints cleanly up to about 5 mm.

We use tree supports where they help, since they touch the part in fewer places. The first layer is pressed onto the plate to grip, which can flare the bottom edge slightly, and a small chamfer there hides it.

PLA is the default. It prints cleanly, comes in the most colours and costs the least, but it softens in the mid 50s °C, so a PLA part left on a car dashboard in summer will sag.

PETG is tougher and handles more heat, so it's the usual pick for working parts like brackets and clips. ASA takes the most heat and holds up in sunlight, so use it for anything that lives outdoors. None of them is certified food safe once printed.