Comparing Machining to;
You may be looking into the pros and cons of using 3D printing over machining, which is understandable considering the cost difference. Likely the most important aspect of your decision will hinge on the type of material you need for your product and the quantity.
3D and FDM machines build parts bottom to top, the parts can be made with internal components already in place, and you have the capacity for more complex shapes. While the cost per part is generally lower than machining, and the production numbers will be higher, the materials used in this process are limited.
One example for CNC machining vs. 3D printing is in regards to a living hinge. This is a design where the material is the same for the hinge and the parts it connects on either side. While you can print living hinges with 3D equipment, the thermoplastic material used in the Selective Laser Sintering (SLS) process will show signs of wear and weaken with repetitive use. CNC machining can cut Polypropylene, which is perfect for living hinges as it can be bent millions of times and still work beautifully.
Water Jet Cutting
This is the most versatile of the cutting options, until specific depth cutting is required. Of the few key drawbacks, the primary drawback is that Waterjet cutting is designed for through-cutting, meaning it can be difficult to cut only to a certain depth, and its quite the challenge to program an effective depth cut that is not a through cut. Projects requiring specific depth are better suited to other cutting methods.
Laser Fuel Cutting
Laser cutting is great for the diversity of materials that can be cut with this method, until we start talking plastics. There are a significant number of drawbacks in cutting plastic with lasers. Plastics may have a charring effect within the cut, causing discoloration. In addition, lasers are challenged with hairline fractures within the cut, melted edge cuts, and dangerous, even lethal fumes. There are a number of laser cutting facilities that generally avoid cutting plastics, with few exceptions.
Oxy-Fuel Cutting and Plasma Cutting
Used for cutting metal
Plastic Fabrication Longevity and Versatility: