You’ve found a model online, or someone has designed a part for you, and now you have a file. Before you hit send, it’s worth knowing which formats print directly, which need a little work first, and what else to include so the quote is right the first time.
The short answer
- STL, 3MF or OBJ: send it as is. These can be quoted and printed directly.
- STEP: also welcome. It’s the best choice when the part might need changes, and we’ll review or convert it before printing.
- No file at all? Photos, a sketch and some measurements are enough to start. The part is modelled first with CAD design.
What each format is
STL
The most common 3D printing format. An STL describes the surface of a part as a mesh of tiny triangles and nothing else: no colour, no material and, importantly, no units. Most STLs are drawn in millimetres, but if a part comes out ten times too small or 25 times too big, the units were different. Tell us the size you expect and we’ll check the scale before printing.
3MF
A newer format that packages the mesh together with its units, multiple parts and colour or material assignments in one file. Our workshop runs Bambu Lab printers, whose slicer works natively in 3MF, so it’s a great format to send, especially for multi-colour models.
OBJ
Another mesh format, common from 3D scanning and modelling apps. It prints just like an STL. Include the size you expect, as with any mesh.
STEP
STEP files come from CAD programs and describe exact solid shapes rather than a mesh. That makes them the easiest format to change: moving a hole, thickening a wall or adjusting a fit. If your part came from an engineer or a CAD package, send the STEP as well as any STL.
Common file problems (and what happens next)
- Wrong scale: usually a units mix-up. Easy to fix once we know the intended size.
- Holes or broken surfaces in the mesh: common with downloaded and scanned models. Many can be repaired; sometimes redesigning the part is the better path.
- Walls or details too thin to print: fine details can be lost or break off. We’ll flag these and suggest a thicker version.
- Too big for one print: large parts can often be split into pieces that fit together after printing.
We check every file before quoting. If a file needs repair or modelling work, that’s part of the quote, so there are no surprises.
What to send with your file
A file tells us the shape, but not what the part has to do. Along with it, include:
- the size you expect, or one key measurement to check the scale against
- where it will be used: indoors, outdoors, in a car, near heat or under load
- a preferred material and colour, if you have one (see the materials guide)
- how many you need
The quote form takes up to five attachments (10 MB in total), so you can send the file alongside photos or a sketch. We usually reply within 24 hours.