Converting to millimeters (mm)

Why convert to mm?

3D printers require STL files to print from. An STL file is a universal 3D file that you can convert to from almost any 3D CAD package.  The main issue is that all CAD packages are different, some use mm, some use cm, some inches (mainly US software packages) and architectural packages tend to use meters.

We open all our files in mm as standard (industry standard), but we have no way of knowing what it has been saved as. 90% of the time we as humans can tell just by using common sense, but sadly a computer can’t as they have logic, but no common sense (or emotions, thank God).

STL files are UNITLESS – i.e. for a dimensions they just alocate the number – for example 40 across and 30 deep instead of 40mm across and 30mm deep. If you save in cm, it will come out as 4mm by 3mm… which is rather small…. and in inches… 1.57mm by 1.18mm… etc.

How do I save as in mm?

Even if you are working in mm in your workspace in your CAD package, your save as or export settings might be in a different setting – ESPECIALLY if they are US based packages like Autodesk or alike – these tend to export in inches regardless of what you are working in in the workspace (which is annoying).

To save in mm, simple select ‘save as’ or ‘export’ – this usually brings up a window which will have an options button – click that and you should be able to easily navigate to the export units – then obviously select mm.

What if I can’t do this?

Don’t worry – there is a button at the bottom of the quote to send it to manual review – we can investigate it from there and advise.