The flippant answer is, "about $50,000."
3D printers are really just lower-cost, slightly less-capable, rapid prototyping or additive manufacturing machines. These days they sell at prices in the $300 to $10,000 range rather than the $60,000 (and up - way up) associated with their big brothers. Prices have declined to the point where it's possible to buy a very capable photopolymer-based machine for less than $1,500, or a basic, fully-assembled thermoplastic extrusion-based system for $350. Buyers who are willing and able to build a kit can be in business today for as little as $299. 3D printers have some additional, generally-agreed-upon defining characteristics:
- They can be used in an office environment.
- 3D printers are generally small and in most cases can sit on a desktop. RP machines are usually much larger, often free-standing with large appetites for electric power. They're frequently designed to use materials in proprietary cassettes or other enclosed means. While there are exceptions, 3D printers usually can accept materials from a variety of sources.
- 3D printers usually make smaller parts.
- Being smaller on the outside means there's less room to build parts inside. Most 3D printers are limited to making parts that will fit roughly in a cube 8 inches on a side. On the other hand, rapid prototyping machines often provide a build chamber at least 10 inches on a side, and some have build chambers approaching 3 x 3 x 2 feet and much larger. A smaller build envelope also means that it's not possible to make as many parts at the same time. 3D printers aren't necessarily build-size limited, however. Several thermoplastic extrusion entries sacrifice a small footprint to provide huge build volumes of up to a cubic meter.
A wide range of 3D printers. Left to right: (Not to Scale.)
The XYZPrinting da Vinci Jr 1.0 (US$350). Formlabs Form1+ (US$3,299).
The Mojo 3D printer from Stratsys (US$10,000).
(Photos courtesy of respective manufacturers.)
- 3D printers are (often) easier to use.
- As a consequence, they require much less or even no training at all in contrast to rapid prototyping machines. Indeed, it's possible to be making parts pretty much right out of the box with some well-implemented machines. But simplicity comes at the price of flexibility. Unlike RP machines, you may not be able to adjust or select many build parameters, or change them on the fly. Also, be forewarned that the lowest cost hobbyist level equipment is frequently not "Plug & Play." Some of what you save by buying one of these very low cost machines is likely to be offset by the extra time required to get the equipment running reliably and learning how to use it.
- 3D printers are cheaper to maintain and feed.
- You can expect to spend several hundreds to a few thousand dollars per year to maintain a 3D printer and keep it fed with materials, but it costs several tens of thousands of dollars each year to maintain an additive manufacturing system. Simply replacing a laser in a stereolithography machine can cost $20,000, and filling a big vat with photopolymer can easily cost more than $50,000. Most RP systems require proprietary materials, but 3D printers most often do not, greatly lowering costs.
- 3D printers are not as accurate.
- Rapid prototyping machines provide specified accuracy and in some cases produce better finishes than 3D printers today - but the difference isn't an order of magnitude. Actually, the specs are very similar for like-sized parts, and in both cases depend to a considerable extent on the geometry being produced. 3D printers are probably not as repeatable as their more expensive brethren and very few of them actually have specified part accuracy. Most low-cost 3D prinyers specify machine positioning accuracy which in the end means nothing much.
- Material choices are wider for 3D printers.
- Metals are not available at all at the moment in a low-cost 3D printer, although some work is proceeding in that area. However, it's possible to make functional plastic parts for nearly any applications with today's 3D printers. If anything, the range of thermoplastic materials that has opened up around these low-cost machines is wider than the proprietary choices offered by the major manufacturers. Dozens of specialty filaments, including flexible, glow-in-th-dark, wood- and metal-filled materials are available - and at reasonable prices. Many photopolymer-based 3D printers offer a wide range of materials that can be separately purchased, as well.
3D printers are an example of the popularization and progress of a technology. It happens in almost every field. When television was first commercialized, video cameras were large, expensive, delicate and difficult to maintain instruments. They could only be used effectively in a well-lit studio environment and there was no way other than movie film to record what came out of them. And what came out of them was a low-fidelity black and white picture that made it difficult to recognize an individual person. Today, all of the functions of a TV studio fit in one hand, work flawlessly and cost little. Professional equipment is still available, of course. It provides more versatility and better picture fidelity, but most of us don't need those capabilities. So, too with copiers, computers, cellphones and now additive manufacturing.
The reasons for using a 3D printer are fundamentally the same as for using any additive technology: to verify a design; to share information across distances; to make a one-off part - and many others. Only now you can afford to do it.