What file do I upload?

A binary STL. ASCII STL is refused rather than silently misread, so export binary from your CAD package.

How strong is a printed part?

Strong along the layers and weaker across them. Tell the shop which direction carries the load and it will orient the part for it.

3D Printing (FDM)

A nozzle lays molten plastic down one layer at a time, building the part from the bottom up.

Your file is measured and sliced in your own browser, so a price appears before anything is uploaded.

The cheapest way to hold a real part in your hand this week
Large parts, because you pay for the plastic the part uses rather than for a block it was cut from
Iterating — a changed dimension costs another print, not another setup

Layer lines are visible, and the part is weaker across layers than along them — orientation is a design decision, not a detail
Unsupported overhangs need support material, which leaves marks where it is removed
Tight tolerances are a poor fit; machine a mating face instead of printing it

Twenty-odd filaments are modelled, from commodity PLA through to carbon- and glass-filled engineering grades and soluble supports.

Availability depends on the workshop quoting your part; the quote shows you which of them can run the material you pick.

.stl

STL files must be binary. An ASCII STL is refused rather than read incorrectly, so export binary from your CAD package.

Price follows the plastic the part consumes and the time the machine spends printing it, against the rate card of the shop that owns that machine.

Unit price falls with quantity, because setup is spread across the batch.

GST is not included in the quoted price; it is added later, in the order.

Your file is measured and sliced in your own browser, so a price appears before anything is uploaded.