Almost without exception all 3D printers will need to use support material when the model has an overhang that is greater than 30 degrees from the vertical.
On completion of the print the support material is then removed to reveal the completed item. This can be done by washing, dissolving, breaking or vacuuming depending on the type of 3D printer and support material used. The advanced printers used by 3PS have dual print heads (extruders). This means that the printing process can be fed two materials; the material used for the model and a specialist material for support. The specialist material (PVA) that we use dissolves and is easily removed from the product.
The disadvantage of the cheaper single extruder printers is that with only one material available for the printing process, the support material is the same as the model material. This will normally mean that the support elements will need to be broken/cut from the model which will leave “damaging” marks on the model surface supported. This can be mostly corrected with finishing, sanding polishing etc., but can add considerable time and cost to the project.
There are some exceptions to the above - for example, printers designed to use laser sintering and powdered nylon. Using this method the printer prints in a bed of the powder so that the powder itself acts as the support and is relatively easily cleaned off the surfaces afterwards.