3D printers

At Middla we have two Ultimaker 3D printers. a 3+ Extended and a larger S5. These are FDM printers which means they build the object layer by layer using using melted plastic filament. To use the printers you must first pass the 3DPrint Quiz and have their first test print supervised by a tutor or lab manager.

How do I 3D print an object?

1. Obtain a digital 3D model
2. Choose your material
3. Slice your model into many 2D layers using slicing software
4. Print!

Obtain a digital 3D model

• Design your own STL format file using a 3D program of your choice; for example beginner-friendly Tinkercad, feature-rich Blender or heavy-hitter Fusion 360. Great tutorials are available for all of these. Or convert an existing 3D file (such as OBJ).
• Scan an item using your cellphone or Middla's own 3D scanner!
• Download from one of many paid or free libraries online like Thingiverse, Cults 3D, Printables or Patreon.

Choose your material

Nine times out of ten you will be using PLA (PolyLactic Acid) as your filament. This is a somewhat more sustainable plastic made from fermented biomass of corn, sugarcane or similar. It is safe to print without extra ventilation. It is an excellent all-round material that prints easily and at a reasonable cost. If you are buying your own filament please choose one of the following approved manufacturers; Ultimaker, Colorfab, Polymaker or add:north. See under material stores in Useful Links. We use the size 2.85mm.

There are however many other types of filament for different purposes. Some of the common ones are listed here. These require different settings both in software and sometimes hardware, so please contact the studio manager for help with these.

• ABS - lighter, more impact resistant. Unpleasant fumes, not to be used. Choose "tough pla" or x-pla instead.
• TPU - flexible, rubbery, durable filament for things like wheels, grips, phone cases, drive belts. Expensive!
• Nylon - strong, durable, low friction, highly resistant to chemicals.
• Composite filaments - there are lots of different compound filaments which may include metals like steel or brass, carbon fiber, glow in the dark pigment, conductive material, wood or stone/clay.
• PVA  - a special support material, washes away in water. Useful for improved aesthetics and complicated geometry.

Slice your model

Cura slicing software is installed on the Mac closest to the printers at Middla. Here is a quick introduction to the first steps in Cura (ca. 5 mins). You can ignore the section on previewing and monitoring for now, and as our printers are not networked, you will choose "save to removable disk" having inserted the USB-drive from the printer you intend to use.

Print!

• Check that the print core / nozzle and loaded filament are correct and match what you chose in your slice.
• Otherwise, change or load filament according to your slice. Studio manager will go through this on your first run.
• Check that the print-bed is clean from scraps of filament, greasy fingerprints, loose debris.
• Follow the onscreen instructions and menu choices to find your file and choose print..
• Fill in the print job sign with your KTH userid and if you are using private or specialised filament, etc.
• Stay around and watch the first few layers go down to ensure that the print has started properly.
• TROUBLESHOOT!  When, not if, things go wrong, use this visual troubleshooting guide to help.
• Remove your print. You shouldn't be in too much of a hurry, it will be easier to remove as it cools and shrinks from the plate.