I am a novice and have very little experience with additive/reductive modeling so please correct anything that is stated herein... which is in error.
3D printing is an *Additive* process whereby you are adding materiel in order to build an object. The two most common types of 3D printers that you will read about and see on OGR are:
1) Filament printers, which are spools of material that are automatically fed (think, wire feed) into the printer. The printer melts the material (there are many types of material) and injects it on to the plane of the printer where the object is being formed. The filament is added in very thin multiple layers until the object is completely formed.
Filament printing; https://www.youtube.com/watch?v=Vx0Z6LplaMU
2) Resin printers, is a process where a liquid polymer (resin) is poured into the holding dish/vat on the plane of the printer. The resin is UV sensitive. When struck by a computer-controlled UV laser, the resin will change from a liquid to solid state. Basically, the laser “draws” the outlines of the print onto the resin layer and hardens the parts that it touches. The parts that are not touched by the laser will remain liquid. The resin is added in very thin multiple layers until the object is completely formed.
Resin printing: https://www.youtube.com/watch?v=b-sIcYo8isI
Each process has advantages in terms of costs, ease of use and degree of detail. A very general and simplified comparison would be that Filament printers would be somewhat more affordable and easier to use... and that, Resin printers will provide a higher degree of detail.
Conversely, *Reductive* modeling is a process whereby you remove material to form an object. This would include Laser Cutting, Engraving and CNC milling. Each has it's advantages and appropriate application to the hobby. These processes will be presented in another amateur explanation... hopefully soon
Types of 3D Printing Technologies and Processes
The American Society for Testing and Materials (ASTM), developed a set of standards that classify additive manufacturing processes into 7 categories. These are:
- Vat Photopolymerisation
- Material Jetting
- Binder Jetting
- Material Extrusion
- Powder Bed Fusion
- Sheet Lamination
- Directed Energy Deposition
Which 3D printer should I Buy?
That depends... before buying a 3D printer sign up with TinkerCad… it is a free, browser-based CAD program with interactive tutorials. Take your time and go through all the tutorials… then, take the simplest design that you want to create and create it in TinkerCad. At this point you have spent $0.00.
Once completed, you will be in a much better position to decide which 3D printer to purchase... and, you will have a much easier learning curve to the software that comes with your printer and other available CAD offerings.
Scaling... quick reference
When scaling an object you have to make sure that it will fit on the plane (platform base) of your printer. If the object is a little to big for your printer... Semi-Scale ... approximately, (1:56) 87%-88% of O-Scale works very nicely with Post War Lionel layouts.
