From your phone to the printer: getting an STL or 3MF from iPhone or Android into your slicer
Designing on a phone is the easy part; the file then has to reach the computer or the printer that slices it. Every route below is boring and reliable, which is what you want at 10 pm with a part to print.Where the file lands
iPhone and iPad. Safari puts downloads in the Files app, in a folder called Downloads (either on the device or in iCloud Drive, depending on Safari's settings). The download arrow at the top of Safari lists recent downloads and opens the folder. If Safari appends a number or changes the extension to .txt, rename the file in Files; the contents are unchanged.
Android. Chrome saves to the Downloads folder. The notification shade shows the file when it finishes; the Files app (or Google Files) lists it under Downloads. Some phones show a "download blocked" warning for unfamiliar extensions; allow it, STL and 3MF are plain model files.
Route 1: a slicer or printer app on the phone
Several printer manufacturers' apps and some slicer apps accept a 3MF or STL shared from the phone and slice it with a saved profile, sending the job straight to the printer. Which apps do this changes with every release, so test yours once: open the file in Files, tap Share, and look for the app in the list. If it appears and the model opens at the right size, this is the shortest route and the phone never needs a computer.
Route 2: a shared folder
Save the file to iCloud Drive, Google Drive, Dropbox or OneDrive from the Share sheet. On the computer that runs the slicer, the same folder syncs and the file is waiting. This is the route to use when you design in the evening and slice the next day, and it keeps a copy of every file you have made.
A network share (a NAS or a shared folder on the slicer computer) works the same way from the Files app on iPhone or a file manager on Android.
Route 3: AirDrop or Nearby Share
From the Files app on iPhone, share the file with AirDrop to a Mac; it lands in the Mac's Downloads. From Android, Nearby Share (now Quick Share) sends to a Windows PC with the Quick Share app installed, or to another Android device. Both are instant and need no account. The limitation is that both devices must be awake and near each other, which is the case when you walk past the slicer computer.
Route 4: USB
Plug the phone into the computer. Android mounts as a drive and the Downloads folder is visible. iPhone shows photos only over USB, so use one of the routes above instead.
Opening the file in the slicer
Drag the file onto the bed, or use File, Import. A 3MF from SpeakCAD carries the millimetre unit and the model name, so the object appears in the object list with the name you gave it. An STL has no unit, so the slicer assumes millimetres, which is correct; if a slicer asks whether the model is in inches because it is small, say no.
Multi-part files (a box and its lid side by side) come in as one object from an STL and as separate objects from a 3MF. If you want to print the parts separately, download the 3MF.
If the size is wrong
The editor shows the model's outside dimensions under the render. Compare them with what the slicer shows. A factor of 25.4 means an inch conversion was applied somewhere; undo it. Any other mismatch means the wrong file was opened; the editor keeps every version in the project history, so download the right one again (small fixes re-download free).
Fixing a part from the phone after the print
The part came off the bed and the hole is 0.3 mm tight. Open the project on the phone, type the fix, download again (free for small fixes), and send it by the same route. The loop from print to corrected file is under a minute, which is why the phone workflow is worth setting up once.
- 1Find the downloaded fileOn iPhone and iPad, Safari saves downloads to the Files app under Downloads (tap the arrow icon at the top of Safari to see them). On Android, Chrome saves to the Downloads folder, visible in the Files app or the notification shade.
- 2Pick a route to the slicerShare the file to a slicer or printer app that accepts 3MF, save it to a cloud folder the slicer computer syncs, send it directly with AirDrop or Nearby Share, or plug the phone in over USB.
- 3Open it in the slicerDrag the STL or 3MF onto the bed in PrusaSlicer, Bambu Studio, OrcaSlicer or Cura. A 3MF from SpeakCAD carries the millimetre unit and the model name; an STL is assumed to be in millimetres, which it is.
- 4Check the size onceRead the dimensions the slicer shows against the numbers in the editor. If they match, slice with your usual profile. If the slicer asks whether the model is in inches, answer no.